I have drunk coffee all my life and you explore things about brewing coffee which have never crossed my mind. About 35 years ago I went through a period of roasting my own beans to duplicate a historical procedure from the 18th and 19th century. Roasting them in an open pan, I cooled them and crushed them mortar and pestle style and brewed them by placing the grounds in fresh boiling water just removed from the heat. After a minute or two, I would drizzle a small amount of cold water into the pot to settle the grounds. Waiting for about a minute, I would then decant the brew into a replica tinware coffee pot. I still do this when primitive camping and it produces an outstanding cup of coffee. At home, I use a French press or a mocha pot.
That is awesome! I have been telling people about how to do that for years when they are camping and they look at me like I'm crazy. I'm like, try it!👍
@@ronniepirtlejr2606 Exactly, hella awesome and saves money from buying any electrical products All you need is water & heat and your good and something to make great
That's so cool, actually sounds like it would get you great coffe in a weird, unexpected way! Maybe our ancestors weren't so in-the-dark as we tend to think. . .
I imagine the colder the beans are, the more of a "shattering" effect they'll experience when they grind, producing a less uniform grind potentially. Warm, they might be softer, and therefore break into the size that the grinder is asking of them more consistently.
I'm baffled by this. From "has he gone insane" to "has he gone insane but also that's really interesting". What is your secret, James? How do you never fail to make a good video, even if the topic is completely bonkers?
"This all started with the V60 video" We bullied James to make that video and that has made him go completely off the other side 😂 Jokes aside, how temperature affects grind, which affects brew (but only affects taste after grounds have cooled) is really fascinating. I'm definitely curious to see more rigor throughout every stage of the process in hopes of further isolating & putting to words what's really occurring here. Also good talking points regarding affects of heated beans and the resulting aroma when ground; seeing as presenting ground coffee is sometimes a step in consumer spaces, I wonder how that would affect perception of a product.
I've had fresh ground coffee made from hot beans strait out of the half-round cast iron skillet, ground immediately with a colonial era style hand grinder, then brewed on the spot. I have to say that was the best cup of coffee I've ever had. The venue, being by the fire in an arctic forest, probably helped a bit.
That surprises me. I thought that if you brewed with freshly roasted coffee without letting them rest and shed excess co2, the coffee would taste sour and acrid.
Hi James, In our paper we showed that at low T (dry ice, LN2) you made the average particle size smaller than at RT. But at normal freezer T the average particle size got slightly larger. We attribute this to a pseudo phase transition around 0 C (edit here: I originally mislistened and noted that the shots run slightly slower with cooling. This could be due to two effects, the mode of the particles is getting smaller, the volatiles are locked in. Heating causes their release, reducing void space for H2O and slowing the shot time per mL). This shouldn't be confused with the size of the fines decreasing monotonically. In fact, the reason for the skewedness of grinding at RT or likely microwave T (local T of H2O is very very high, the rest is being passively heated), is that you have likely reduced the number of fines being produced marginally, but also vastly increased the homogeneity of the boulders. I sit of the side of the "fines are doing the business", so I'd be inclined to say that heating is problematic. Three other considerations here. I) we use microwaves to accelerate chemical reactions in the lab. The reason it works is microwaves, as I mentioned, specifically target a vibrational mode of H2O. The real test here is controlling for hydration level in the roasted bean. Of course in your samples they are all approximately the same but the corolary to microwaving is that molecules very near the hot water molecules are experiencing much much much higher local T than the rest of the bean. In fact the heat capacity of the bean is relatively low, so microwaving the bean is really just targeting local pockets throughout. In these pockets you may be performing chemical reactions, for better or worse, but it's worth being aware that a microwave is a chemical reactor. Ii) when we cooled coffee we had intended to also heat it using a similar process to Dawn. We couldn't do this scientifically because the deltaT was too great, even when dosing into an EK43. In other words the rate of cooling was way too fast to get good data from. Id be wary of assigning absolute T to any coffee beans using that surface IR device. III) letting the coffee equilibriate to the same T sounds, in principle, like a good idea and minimizing variables but actually at the T range you were looking at *this is your biggest variable*. Chahan and his talented postdoc Samo showed conclusively that the rate of certain volatile losses occured on the seconds (rather than 10s of seconds) time scale and the process is kinetically limited. This means at high T, cooling, vs RT sitting there, the chemical composition of the volatiles has vastly changed. Volatiles are one of the main reasons shots run at different rates - less water, solid interface, lower extractions, etc. When you grind hot you drive off more of these, and while your EY doesn't change (lets not talk about that measurement though...thats clearly problematic given the experiment I just described) your flavor profile does. Anyway, good compelling discussion but I sincerely hope we don't see people microwaving beans in the future, if only because reproducibility will nose dive.
@James & @Christopher, For me the quick comment that got me really thinking here was when James mentioned the Mythos One and it's heating element. Currently I have the pleasure of testing the newest Mythos 2. Not only can one choose on demand the temp of the heating element, but also motor RPM. So out of curiosity I cranked up the heat from my last dial in where I had set the grinder and RPM to it's lowest settings (30C, 700RPM). At the lowest settings the espresso blend I was working with was insanely sweet, high clarity of flavor, ripe acidity, with a very creamy body. I chose this blend to work with as differences in flavor/tactile are easily perceptible. I attributed most of the positive aspects to the lower RPM speed. Next I cranked up the heat to 50C. As expected the extraction time sped up significantly. Which then caused me to start grinding significantly more fine. After a few adjustments I got an espresso in line with my typical recipe. I found the body to still be quite enjoyable but the sweetness reduced and overall clarity of flavor declined. Had I more time to really play around with these variables my next experiment would be to also turn up the motor RPM a touch. Seems like heating coffee up and grinding is to mimic "peak" grinder operation. I'd like to see more being done in grinder tech to keep things more cool. Thanks for keeping interesting coffee conversations going, loving it!
Hey! Thanks for the comment. A few quick things: - The shots ran slower, not faster, when beans were around 0C and below. - I thought a lot about H20 retained (or more accurately reabsorbed post roast) back into the coffee bean - it is something we don't really talk about in coffee, and it's distribution in the coffee bean too. I was suprised that microwaving worked as quickly as it did. (My other thoughts didn't really go anywhere) - It's interesting that regardless of heating method (water bath vs microwave) that you can still effectively up your yield for a given contact time. - I've never (or to my memory) seen anything on volatile loss vs flow rate. Is there anything published you can link to? - I'm not really proposing that people microwave coffee in a meaningful way - it's just a fun experiment, where I was surprised to stumble upon the effect, and more surprised that it didn't make the coffee taste at all bad. That seemed worth sharing...
@@jameshoffmann Ah sorry, I miss-listened regarding the rate in which the cold shot ran. Without sounding like "I can't be wrong", this new data does make some sense. Cooling the coffee does make the mode size of all particles smaller so it going slower is the expectation. This in combination with the retention in volatiles evidently results in a marginally slower shot. The fact your coffee yield goes up with T is an argument for extraction being kinetically limited - higher average T, higher EY. But what EY do you want, that is the question. Re volatile loss vs flow rate - no data published that I am aware of, but certainly true from my experience in large scale batch reactor setups. I guess someone will publish on this at some point?? And finally, of course, I know you aren't advocating for this ;). I'd like to show you an equally crazy idea I've ambiently been working on. I wonder when I will see you next.
@@jameshoffmann: I am not a researcher, would be the effects of using colder beans for espresso, seeing that shots run slower that way, therefore dissolving more solids?
Sitting here with a 25.6% avg extraction, What I do think is that the difference have to do with co2, non microwaved beans during bloom smells of co2 very unpleasant microwaved beans don't have that smell, It's just instant pleasant aromas during bloom. Very nice James thank you for sharing
Tried it today for pour over, there were so incredibly few fines that it drained insanely quickly, and I had already ground finer anticipating that. I might be able to go a whole setting lower with my Lido 3, which would be the finest I'd ever attempted on a pour over. Even today with the "too coarse"/fast draining brew, I am getting good flavor, the sweetness is amped up. Yesterday I tried it with the Flair and maybe over compensated on grind, going too fine and sustaining 10 bar, but it tasted good - again, amped up and syrupy sweetness. Starting to see a trend?
Very interesting indeed. My hypothesis as to why this happens is as follows: Every grinder crushes the beans to an extent. The sharper the burrs, the less that happens I would guess, but it still happens. The crushing makes the beans break apart in places that they might already be weaker in, which produces fines. You can try that by cutting a coffee bean in half; even with a very sharp knife you will get many small particles. Now, if you heat the coffee beans, the moisture in there in there spreads through them, making them softer and more elastic. Thus, the burrs have an easier time actually cutting the beans, and less "shattering" occurs, which leads to less fines being produced, and thereby finally to the ability to grind a bit fine and extract more. I'd be curious what you guys think
I just woke up to thinking about coffee roasting then turned on the computer :) It seems to me old dry bread in a microwave brings it back if nuked for very short period of time by adding some moisture. An oven seems to do the same. I want to try this with some old dry (carbonized) toast and see what happens. I do wonder if its the oils in the bean or humidity in the air that is effecting it most but then heat may make the roasted bean more pliable/elastic. I notice dark roasts leave a lot of sludge when using a French press so I will have to see what happens by warming the beans with and without a small amount of humidity in a sealed bowl. I just looked this up and think it may apply. watch?v=YPNcTIauATw
Really interesting video James. Are there two things happening? 1. Heating the beans accelerates de-gassing - which is why you aren’t getting the same affect post-grinding 2. Warmer ground coffee allows the water to flow through quicker
Alton Brown from the Food Network Good Eats program has an episode ( from some years ago ) where he recommends to warm up the coffee beans before grinding. This "reactivates" the essential oils and brings them to the surface. I do this now with a dedicated kitchen pan and the coffee tastes much much better. I warm up the beans for 5 min... constantly moving and stirring the beans in the pan, fine grind and brew.... fantastic results every time
The one thing missing is some kind of microscopy on the heated/cooled beans, the partially ground beans and the end result. That may give a clue as to what is happening and why the end results are different.
To minimize grinder static I used to slightly moisten my beans using the wet spoon trick. But when grinding for espresso I had infuriatingly inconsistent grounds retention in my Graef CM800. Since I weigh both before and after grinding, this frustrated me enough to revisit my Hario Skerton hand grinder. However grinding for espresso with the Skerton is maddeningly time consuming. But lo and behold, microwaving the beans rewarded me with stable and minimal grounds retention and as an added bonus it improved extraction dramatically. My wife often thinks I get a bit too silly/nerdy/obsessive about coffee, but thanks to you my coffee making skills have improved immensely. Thank you James! I hope you have a great day.
I've been watching your videos for a while now, I've been a coffee drinker for 20~ years and only now am I starting my journey into becoming an espresso enthusiast. You inspired me to tinker and experiment with what I've had - V60 pour-over kit - to get the best coffee out of it. But now I'm looking to get into the Espresso world - I was lucky enough to find a '91 Gaggia Baby that was treated well to go with the ROK manual grinder I purchased. Thank you for making the sciences of coffee fun in a very humble and direct way, I really appreciate your humour and you've become my go-to for coffee knowledge. I look forward to more Weird Coffee Science from you!
I see a few people saying about extra “roasting” your bean in the microwave. Microwaves don’t work like that. How a microwave works is by simply agitating the water molecules in the bean to heat them up and in the process would be making the bean softer from the inside out. Just think this we have all done the following at some pintbun time, you get a piece of stale bread put it in the microwave for a few seconds to get it up, but it come out soft and fresh. That’s because the water molecules in the bread have been agitated and heated to to make the bread appear fresh. The same would be happening to the coffee beans.
This is super interesting! Just tried with a v60 and it reduced my draw down time by a fairly significant amount. I also think fewer fines were produced when grinding. I didn't however, allow the ground beans to cool down so I did taste some of the unpleasantness/over extraction that you mentioned towards the end of the video. Definitely going to experiment some more.
i would have tried doing 1/3 hot grind 1/3 cold grind and 1/3 room temp grind in the same cup to see if you broaden the flavors across the entire spectrum.
I'm actually kind of surprised that someone didn't mention a hot-air popper. It would take a few trials to figure out how long to 'pop' the beans, but it would work quickly--surrounding them with *LOTS* of really hot air--and can sit in the corner of your coffee cupboard without taking up a lot of space.
I tried this and it was night and day, the coffee changed completely. This may make a small difference if you have a good grinder but I have a Krups gvx that I bought 15 years ago and blasting the coffee beans 2x 30sec in the microwave brought flavors that I did not know my nice coffee had. Brewed with french press and everything was weighted and timed so no possible error. Maybe James should revisit this and see what difference it makes with different grinders.
Today ground hot beans ( cooled down just a tad), microed 1 minute on high in a ceramic cup. Did my Clever in the brewer into the nuke box to maintain brew temp pour over method 2 mins on low after grinds over hot water method (took a good minute of stirring to sink the grinds) so basically a 3 minute brew at boiling. This time did not get a "flat bottom" grinds very much stuck to the sides of the filter paper. AWESOME CUP!!!!!
This is old but hope you see this. I have a coffee TRUCK. Not a shop. My biggest issue is that the temperature and humidity in my truck vary wildly as the day progressed and I have to constantly adjust my grind and dose to keep a consistent shot. The hotter it gets, the finer I have to grind and the dose changes from less to more from 16 to 18 grams. It's a pain in the honey. My roaster thinks I am crazy, but of course he has a regular shop where the temperature stays constant from the moment he opens to the moment he closes.
French Press by Bodum using plastic frame, used for Brewing 60g whole beans frozen in Ziploc for freshness a la George H. Sealed ziploc put in microwave with warming coffee cup full hot water. Microwaved until beans warm to touch. Ground in Rocky set to 20. Put in preheated French Press, which half filled boiling brew water, vigorously stirred, adding remaining Litter. Microwaved at 4 minutes to keep brew temp up arround 93C. Poured at 10 min total brew time. Fully extracted, like dark brown velvet covering on memory foam pillow. Roast: Medium Dark, not surface oily, not dry beans, blend Central & South American Arabica from altitudes greater than 1200 meters. Brew water ppm:150;10;10 Ca, Mg, CO3 a la Monika K. My better half liked the coffee black for the first time!! I liked the coffee black from hot to tepid; and it also made a great " strong coffee ice cream flavor with heavy cream and stevia; Keto either way. I love the ability to independently control variables using French Press. Grind size, brew time, temperature independently controllable. As are brew water Ca, Mg hardness and CO3 buffer. I have begun at a grind size that also works for Venus Bialetti on my induction plate. This grind size is about 100 micron radius, as suggested by a video on maximizing extraction fraction. This brew water starting pH 7.69 and brew is pH 6.34. Love coffee science! Don
I recently made the mistake of purchasing roasted coffee beans from one of my favorite local coffee shops; the shop sells fresh, but Amazon delivered comparatively (over 2 months after roast) old / stale beans; the only way I could tolerate those older beans was to first microwave them for 4 mins @ 50% power (20g spread out flat in a large 4c pyrex measuring cup) … flavor was sufficiently rehabilitated fyi - my brew method is Flair 58 LE, with Goat’s Arco hand grinder
I use a Moka Pot and have always enjoyed the taste of dark roast beans that are keep in the freezer but I have never thought about heating them in a microwave. I am going to have to try this now. Over the weekend I ordered an espresso machine and can't wait to start experimenting with it.
The solution is easy. First you package the beans frozen in cup to full pot sizes. Then the fun part is a custom grinder that has a heating element that you would put the grounds into. Slowly bringing the grounds to temp then it heats the grounds to the desired temperature and to texture. Think easy bake oven with a digital clock. it could connect to coffee maker of proprietary design. Flushes itself with water then air.
Consider that heating dries the beans and getting cold beans out of the freezer into the room temperature causes condensate, which increases the moisture content. When I get fresh beans from the local coffee shop and pull fresh shot the same day I get one flow rate. After the beans sit at my place, which almost always has drier air than the coffee shop due to heating or air conditioning for a few days, then I get a very different flow rate. That of course with all the other variables like grind size, etc being equal.
I did a variation. I have a microwave that is also a convection oven. I normally use the 100 degree Fahrenheit setting for raising bread dough. So I "raised" my beans for 5 minutes and put them through the Rocky grinder. The result was much less clumping and a fluffier grind. I reduced the grind setting one notch. A dark roast is a little sticky due to caramelization of sugars during roasting. My medium roast is not sticky. However, while my fingers do not recognize the beans as being sticky, the grinder seems to disagree. Coffee beans are notorious for being able to pick up flavors. It appears they also are somewhat hygroscopic and a brief stint in the oven dries out the surface moisture that they pull out of the air. The grinder definitely likes the drier beans better, The puck is wetter at the end of brewing due to the finer grind. My bottomless filter basket shows no spatter and more even flow. A work of caution here. I do things differently. 23 grams in the basket gets brewed then divided into two 10 ounces mugs which get diluted to make a total volume of 20 ounces. This is coffee for 2 made by Miss Silvia. This works for us and is a large improvement over our old Kurig which we gave away to a worthy cause. Miss Silvia is stock except for the addition of a PID temperature control. The NotNeutral mugs fit under the bottomless filter, but not the standard filter basket. The PID is temperature only, preinfusion is done manually with a stop watch. Our first Kurig died when the electronic display quit working. If my stop watch quits, I can replace it on my next trip to the grocery store and it will cost less than $10, If the PID dies, I can revert to factory default, or replace the PID which I installed myself. I can get parts for Miss Silvia. No more unrepairable coffee machines for us. However, I can't brew coffee and talk on the phone simultaneously and I wouldn't want to insult the beans by doing that.
ANOTHER SUCCESS. microwaved some fine whole beans 30 secs on high (plenty hot also let cool to around body temp b/4 grinding this time) this time in a plate for better heat distribution than a mug, then in Clever basic bloom pour over then 2 minuted low in micro to keep brew temp at/near boil. A FINE CUP INDEED. Surmise the at boil brew impacts brew taste more than the brief nuking. Hard to know since I don't have it in me to do 3plus solo cuppings.
Microwaves are a bit different, so results may vary. An IR-thermometer like that costs from about £7 - and you can probably think of other uses for it as well :) If you have a milk thermometer, perhaps you can use that in stead?
Ground my coffee, then microwaved grinds then brewed clever pourover grinds atop hot water method today. Results........EXCELLENT CUP. Shoot looks like I accidentally deleted details of my 1st microwave beans cup also tasty. Have only had two mishaps......burned beans once, and the boilover debacle below.
I gave this a shot - punsssss. It made the most difference with stale beans for me. I could extract a bit more flavor and produce less bitterness. I still don’t think you need to cool the beans before pulling the shot though, especially if you pre-infuse.
There have been papers written about it. Easy. Coffee becomes more brittle as the temp of yhe bean goes up. That leads to coffee particles being more inconsistent in size and less uniform which also leads go faster shots. The cooler the coffee is, we will get the opposite effect. This is how the whole freeze your beans craze started, it mainly leads to more uniform particle size, tighter density in the puck, longer shots.
I don't have a way to measure the temperature, so I just microwaved my beans until they felt "strongly warm but not yet hot". Grinding with hand grinder, the feeling definitely changed, it feels like grinding something a tiny little bit more... "elastic"? I'll try to make beans even hotter next time and see if there is any difference. Will update when beans cool down, gonna make some stove moka pot coffee. It also made me wonder, if anyone working at coffee roasting place ever tried grinding coffee immediately after roasting, when it was still relatively hot? Or let it cool only partially and just toss it in a grinder? Then, when roasted and ground coffees are cool, grind some more roasted coffee, brew, and compare both? Edit: Inspected what I ground, and I was honestly surprised! A lot more bigger pieces (but the desired-size big), a lot less smaller pieces and fine particles. Also, I should have measured brewing time, but I swear it was a bit faster than usual (for this 3c size moka pot). Waiting for the coffee to cool down a little, will update on the taste. (Beans used: medium roast Brazilian beans with milk chocolate/nuts/cocoa flavour profile. No acidity.)
You should try cashew coffee! I had it this morning for the first time and was very impressed. It tastes almost the same as an almondmilk latte but is just freshly brewed coffee and cashews mixed in a blender.
While living on Hawaii Island I bought green Kau coffee beans and roasted them in my oven I let them cool to the touch and ground them The coffee was stunningly delicious.
Today's "microbrew" nice Ethiopian beans nuked 1 min on high (3x 20s actually to be scorch safe) Ground stil warmish. Brewer nuked 2 mins on power level 20 (next to lowest on my box) Again smells extra yum ground. Did grinds over water method. Again super heady/bubbly/bloomy so stirred top cafe layer quite a bit. Brew poured through quite quickly, nice "bed" few side clingers. Smells wonderful. Now for taste its at chosen temp.....did i brush my teeth.........yes.....EXCELLENT.......no sign of over extraction, I think I'd have liked to have brewed it 3 mins. I haven't had this same bean in 2 or more days so can not say hella better than sans bean preheat, and I've brewed it several ways. Its just VERY VERY GOOD. Weird????? Yesterdays made similarly was extraordinary.......but those were extraordinary beans to start with. these are far from meh....very good. I've had them maybe 10 days stored well.
I now use this hack every day. The first time I tried it my wife complained the coffee was too strong. So, I'm using about a tablespoon less beans per pot. This also solved the problem of grounds from frozen beans clumping on the inside of the grinder I guess because of condensation. Even for our boring old drip coffee, usually Aldi's San Pablo Estate from Peru, this seems to have made a significant difference.
I currently work for a coffee kiosk company and the first time I noticed this temperature phenomenon was a couple days into working for this company. The shots in the morning were fine and consistent then mid morning I found myself struggling to keep the shots consistent. Every single pull yielded a different result. Then I noticed the sun was beating down on the grinder. I put my fingers in the hopper and, sure enough, the beans in the back were much cooler then the beans facing the sun. I stuck a thermometer in and there was a 70 degree difference between the front and back. It made so much sense because things that are warm are more mailable than things that are more cold and brittle. I made a makeshift hood and the temperature stabilized as did the consistency. The most annoying thing is that some kiosk managers don’t want you to ever adjust the grinders 🤦♂️
Paul Aspen correct in you assumption. If you work in an air conditioned environment where the ambient temperature and humidity is constant there is no need to adjust your grinder. If you Coffee station is out in the elements you’ll need to adjust your grinder depending on the hour of the day, the humidity, and the ambient temperature. This all affects the grind of your bean, and your grinder should be adjusted accordingly to suit the surrounding elements.
Warming the beans will make them softer and less brittle, so the grind will be more consistent. Being less brittle also means less shatering, aka "fines"
Grinding also makes the larger masses smaller which is contributing to the greater heat absorption. Not to mention the friction and pressure of grinding itself.
Some wild guess: Microwave vibrates water molecules. It frees the water molecules from the coffee-bean cells so the beans are dryer. It may makes the bean cells' moisture uniform. Thus, the grind produces more uniform particles. Also, despite the water molecules, generally hot things should be easier to be cut/broken because their particles have more potential energy & don't really "mind" to separate from each other. So, it's easier to be cut by the grinder & the result is a more uniform grind.
The physical chemistry of the coffee brewing is just fascinating. I think it's not only the temperature but the humidity content in the coffee beans, maybe that present quantity and state of the water molecules contained is affecting the quality of of the flavor of the brewed coffee. Why? Well microwave's heating may have those water molecules in a more excited state and disolving part of the aromatic and other soluble molecules inside the coffee beans. Microwaves are known for being capable of uniform and efficient heating so maybe that mild heating and posterior cooling before grinding makes the coffee beans more "juice" wich in the end could be the difference in the taste on the espresso cups. This is a really fascinating topic. Nice video and thank you, the topic is surely worth of a series of more experiments after all there are more variables to consider.
It's kindy funny that all that years I heard that an advantage of burr grinder over the blade is that the former doesn't heat up grounds while grinding. Turns out it may actually not be bad! (use burr grinder though not to avoid heating up the beans but to get far more consistent particle size). Is there an easy way to heat up beans without microwave that can be incorporated to a morning routine?
For coffee or espresso? I guess with an espresso machine you could put a little tray with beans on the cup warmer on top while it's heating up (except, in my case, I got a pavoni and no microwave, so I guess I'm out of luck ¯\_(ツ)_/¯)
I might test it, but I have a few strange questions... one I want to know what it will do if I put coffee in a steamer, like my rice cooker, another what will it be like if I try to roast my coffee in a slow cooker? What will coffee taste like in the slow cooker like stewed coffee? Hmm Nothing seems to be a good idea, but I am curious.
james could make a 20 minute video comparing the different types of hand crafted chocolate that are better suited to pour over beans and chewing on them
@@sebaba001 I’ll second the idea of finding the best chocolate coated coffee bean as a video concept. That could be really interesting, which chocolates, and which beans, make the ultimate chocolate coated coffee bean.
This actually makes perfect sense! Freezing the beans would make them more brittle during grinding, and therefore more likely to break into inconsistently-sized particles. Heating should have the opposite effect, reducing the brittleness, and creating more consistency in the grind size.
I use to have a high end stereo store. Lots of listening in our reference room. This was in the late 70's, early 80's ( a very volatile time in the stereo industry}. Bottom line, is that people frequently preferred the "different" to the more accurate (reference). I wonder whether some of that isn't going on with our coffee tasting. Just saying.
I think it would actually be pretty simple to replicate commercially, given the important factor is heating the beans, and not the microwave interaction... I think just pour it into like a jacketed hopper that is kept at X temp. grind per order, either tamp and wait, or par grind as needed.
I actually have thought the idea of microwaving coffee beans would work, and had done it, but didn't experiment much with it - I didn't know what temp they were before grinding or brewing, etc. So I'm really happy to see you went the next steps with this! I'll play around with it more myself to see if I can get a noticeable, reproducible improvement in flavor that's worth the added bit to the process.
As a coffee enthusiast, one of the things that I like about it is how different of a food it is, but sometimes I wish we would spend effort into trying to make "acorn muffins" or "maple tree seed tea" or even a cinnamon substitute made from entirely pine cones. #nuts
Tried heating the beans up. I think my coffee tastes better?... I'll keep doing it. The static that I experienced with my Lido hand grinder is no longer an issue - an unintended result of heating the beans - THats Gold son Gold I say...
Hey James, as always, love your videos. Thank you for all the information! I was wondering whether you have any interest in making a video on decaf coffees. I drank coffee for the caffeine for over a decade before discovering specialty coffee, and for the first time, I'm completely infatuated with the taste of coffee. And I'd love to find great decaf coffees that would let me enjoy that kind of taste well into the evening. Thanks again. Cheers!
Maybe when warm a few hits and they get punched into pieces - like kicking a cake - as you do - and then chomped easily to size with no hassle. But when cold, they bounce around between burrs many times, collecting a multitude of little fractures, then getting pressured to cave in, but resisting , producing more and more fractures, like kicking a glass ball around - which contribute to produce overall smaller grind and shatter when chomped down. So in short - I think it's fractures. IF that's true, I think you'll see MORE crema, because the chunks will remain big, so retain their gas.
Never microwaved the beans, but when I used the porcelain and glass v60 I used to spray them with water and microwave them to heat them up. Worked better than using water from the kettle
I was born on an island where coffee beans cherries could be picked and on the side of the road. The start and end of a cup of fresh coffee being grilled in brown sugar and pounded to powder and turned into coffee right in front of you is amazing. of course hot ground beans taste better. they did not have grinder back home but the espresso made there can never be rivaled by modern day espresso makers.
Hey ! I have travelled to many coffee producing nations and have witnessed that the locally available coffee beans suck there with best beans getting exported and locals drinking crap Grilling coffee in brown sugar sucks and is only good to cover bad beans. Never seen a decent high end espresso machine in a 3rd world coffee country with locals knowing nothing about real espresso.
OK, added microwaving my two scoops (Yes I know,,, SCOOPS!) for 22 seconds and slowly adding the beans to the grinder rather than just filling it up and letting it go (another of your videos) and the taste has very noticeably improved. Fines have drastically disappeared and the results are far more consistent. I was having issues with occasional higher levels of bitterness. I use a gold metal filter in my Aeropress with a dark roast. 185f.
Didn’t we all learn with the trend of the small spray bottles that water content does have a significant impact on grinding? I feel like the heating is mostly drying the beans which then leads to the described effects. Would be fun to compare vacuum sealed and heated beans (sous vide) with the microwave experiment…
Tried again diff beans 20 secs on high cooled b4 grind. This cup is a bit bitter/ over extracted, but I can not attribute that to bean prewarming. Hmmm
Ok. Here’s my theory. It may be that the slightly higher temperature of the microwaved coffee beans increases the elasticity of the cellulose in the beans. This increased elasticity could cause a narrowing of the peak of the grind distribution or a least reduce the number of fines caused by the shattering of coffee bean particles during the grind..
Perhaps the thermal expansion and compression has an effect on the beams as they’re grinded, like a shrinkydink, you can get much more “detail” that you wouldn’t normally get.
We had a pretty engaging conversation on this topic going on H-B right after Chan's WBC presentation. I'm glad to see you investigating it and sharing your thoughts as well. I played with this a lot, and it certainly helps with pushing bright sours into bright ripes. It really enhances the assertive fruity powerhouse coffees in my opinion, but for tamer coffees, i.e. pulp natural Brazils, most Indo's etc, not as much. Here's a suggestion you might like to play with and report back. Flip the script completely on this experiment, but aimed at a different target. Take a darker roast, a blend, anything that's seen second crack, and do a pour-over brew session that begins with a simple plastic bottle of water chilled in the fridge, to completely pre-wet the entire grounds bed before then proceeding to extract with whatever temp off boil you prefer and report back. It might REALLY surprise you. I'm not going to dump forum links on someone else's social without permission but I've written about that too. Great video!
@@jameshoffmann www.home-barista.com/tips/sous-vide-espresso-extraction-wbc-finalist-dawn-chan-kwun-ho-t35328.html And my method for a cold start for dark roasts noted here, was inspired by and credit goes to Lucio Del Piccolo and what he shared with the coffee world in regards to cold starts for mocha pot brewing. www.home-barista.com/brewing/cold-water-start-for-dark-roasts-t53568.html I have yet to find a darker roast that didn't benefit from this little trick.
@@jameshoffmann And Lucio Del Piccolo's discussion was circling around the concept of simply pre-wetting the mocha pot bed of coffee before beginning the brew. I took this to the next logical step when applying it to brewing darker roasts. Both center around a simple concept of a heat soak. Starting with cold water and forcing the brew temp to be exaggeratedly cold towards hot from the beginning really does some fascinating things that remove the nasty distillates or harsh roasts notes in darker roasted coffee. This method honestly makes me love darker roasts a lot more than I used to. www.home-barista.com/brewing/how-to-improve-your-moka-pot-coffee-t48638.html
I've gotten more and more into coffee in the last few years and it's become a real passion of late. And I've found these videos super interesting! I'm going to try this. Thanks!
I had two drip machines, 1 cud brew 6 cups, the other 2 cups. Trying them both with same amount of water and same amount of the same coffee gave me 2 very diff result. Coffee from the small machine came out much more delicious. The only noticeable diff in brewing was that the small machine took longer to brew the same amount of coffee. Maybe 12 seconds slower.
The grinder won't bring down the temp of the beans if you also heat it up in the microwave first
Mas Tun im not sure if youre uninformed of how microwaves work ok you just want to see the world burn down 🧐
Kiarash Nox - Latter
Brilliant
Gonna try that tomorrow.
Good coffee is more important than an intact house obviously...
My grinder won't fit in the microwave. Bummer - or maybe thank. God!😂😂
The skill of Gareth spinning 2 espresso's at the same time without causing a mess did not go unnoticed
He's the best!
Yeh, but didn’t James tell us to stop swirling?!
@@samroesch, Yes! Stir! :D
What happened to “shaken, not stirred”?
This... This is the nerdy coffee stuff that sparks joy.
It's official; the V60 video has made James mad. I knew that video would come at a price.
Haha! Also, possibly true
I have drunk coffee all my life and you explore things about brewing coffee which have never crossed my mind.
About 35 years ago I went through a period of roasting my own beans to duplicate a historical procedure from the 18th and 19th century. Roasting them in an open pan, I cooled them and crushed them mortar and pestle style and brewed them by placing the grounds in fresh boiling water just removed from the heat. After a minute or two, I would drizzle a small amount of cold water into the pot to settle the grounds. Waiting for about a minute, I would then decant the brew into a replica tinware coffee pot. I still do this when primitive camping and it produces an outstanding cup of coffee. At home, I use a French press or a mocha pot.
That is awesome!
I have been telling people about how to do that for years when they are camping and they look at me like I'm crazy. I'm like, try it!👍
Cowboy Coffee and wow Mortar & Pestle,
I feel like I found my relative when I heard this,
I'm definitely screenshotting this
@@ronniepirtlejr2606 Exactly, hella awesome and saves money from buying any electrical products
All you need is water & heat and your good and something to make great
That's so cool, actually sounds like it would get you great coffe in a weird, unexpected way! Maybe our ancestors weren't so in-the-dark as we tend to think. . .
The Turkish way
I imagine the colder the beans are, the more of a "shattering" effect they'll experience when they grind, producing a less uniform grind potentially. Warm, they might be softer, and therefore break into the size that the grinder is asking of them more consistently.
Dammit, now I have to add another 10 minutes to my morning routine 😅
I'm baffled by this. From "has he gone insane" to "has he gone insane but also that's really interesting". What is your secret, James? How do you never fail to make a good video, even if the topic is completely bonkers?
this topic isnt bonkers 😂
"This all started with the V60 video"
We bullied James to make that video and that has made him go completely off the other side 😂
Jokes aside, how temperature affects grind, which affects brew (but only affects taste after grounds have cooled) is really fascinating. I'm definitely curious to see more rigor throughout every stage of the process in hopes of further isolating & putting to words what's really occurring here.
Also good talking points regarding affects of heated beans and the resulting aroma when ground; seeing as presenting ground coffee is sometimes a step in consumer spaces, I wonder how that would affect perception of a product.
The secret is too much coffee
When James comes home drunk and brainstorms video ideas
Thats what coffee vodka does to you
*baristastorms
This video should've been sponsored by Empirical Spirits.
I've had fresh ground coffee made from hot beans strait out of the half-round cast iron skillet, ground immediately with a colonial era style hand grinder, then brewed on the spot. I have to say that was the best cup of coffee I've ever had. The venue, being by the fire in an arctic forest, probably helped a bit.
Sean Dees I need to try this!!
That surprises me. I thought that if you brewed with freshly roasted coffee without letting them rest and shed excess co2, the coffee would taste sour and acrid.
@@HaydenX Something in the arctic forest might have played a role in speeding up the degassing process 🧐.
@@PCT6566 Elves, no doubt.
Hi James,
In our paper we showed that at low T (dry ice, LN2) you made the average particle size smaller than at RT. But at normal freezer T the average particle size got slightly larger. We attribute this to a pseudo phase transition around 0 C (edit here: I originally mislistened and noted that the shots run slightly slower with cooling. This could be due to two effects, the mode of the particles is getting smaller, the volatiles are locked in. Heating causes their release, reducing void space for H2O and slowing the shot time per mL). This shouldn't be confused with the size of the fines decreasing monotonically. In fact, the reason for the skewedness of grinding at RT or likely microwave T (local T of H2O is very very high, the rest is being passively heated), is that you have likely reduced the number of fines being produced marginally, but also vastly increased the homogeneity of the boulders. I sit of the side of the "fines are doing the business", so I'd be inclined to say that heating is problematic. Three other considerations here. I) we use microwaves to accelerate chemical reactions in the lab. The reason it works is microwaves, as I mentioned, specifically target a vibrational mode of H2O. The real test here is controlling for hydration level in the roasted bean. Of course in your samples they are all approximately the same but the corolary to microwaving is that molecules very near the hot water molecules are experiencing much much much higher local T than the rest of the bean. In fact the heat capacity of the bean is relatively low, so microwaving the bean is really just targeting local pockets throughout. In these pockets you may be performing chemical reactions, for better or worse, but it's worth being aware that a microwave is a chemical reactor. Ii) when we cooled coffee we had intended to also heat it using a similar process to Dawn. We couldn't do this scientifically because the deltaT was too great, even when dosing into an EK43. In other words the rate of cooling was way too fast to get good data from. Id be wary of assigning absolute T to any coffee beans using that surface IR device. III) letting the coffee equilibriate to the same T sounds, in principle, like a good idea and minimizing variables but actually at the T range you were looking at *this is your biggest variable*. Chahan and his talented postdoc Samo showed conclusively that the rate of certain volatile losses occured on the seconds (rather than 10s of seconds) time scale and the process is kinetically limited. This means at high T, cooling, vs RT sitting there, the chemical composition of the volatiles has vastly changed. Volatiles are one of the main reasons shots run at different rates - less water, solid interface, lower extractions, etc. When you grind hot you drive off more of these, and while your EY doesn't change (lets not talk about that measurement though...thats clearly problematic given the experiment I just described) your flavor profile does. Anyway, good compelling discussion but I sincerely hope we don't see people microwaving beans in the future, if only because reproducibility will nose dive.
@James & @Christopher,
For me the quick comment that got me really thinking here was when James mentioned the Mythos One and it's heating element. Currently I have the pleasure of testing the newest Mythos 2. Not only can one choose on demand the temp of the heating element, but also motor RPM. So out of curiosity I cranked up the heat from my last dial in where I had set the grinder and RPM to it's lowest settings (30C, 700RPM). At the lowest settings the espresso blend I was working with was insanely sweet, high clarity of flavor, ripe acidity, with a very creamy body. I chose this blend to work with as differences in flavor/tactile are easily perceptible. I attributed most of the positive aspects to the lower RPM speed. Next I cranked up the heat to 50C. As expected the extraction time sped up significantly. Which then caused me to start grinding significantly more fine. After a few adjustments I got an espresso in line with my typical recipe. I found the body to still be quite enjoyable but the sweetness reduced and overall clarity of flavor declined. Had I more time to really play around with these variables my next experiment would be to also turn up the motor RPM a touch. Seems like heating coffee up and grinding is to mimic "peak" grinder operation. I'd like to see more being done in grinder tech to keep things more cool. Thanks for keeping interesting coffee conversations going, loving it!
Hey! Thanks for the comment. A few quick things:
- The shots ran slower, not faster, when beans were around 0C and below.
- I thought a lot about H20 retained (or more accurately reabsorbed post roast) back into the coffee bean - it is something we don't really talk about in coffee, and it's distribution in the coffee bean too. I was suprised that microwaving worked as quickly as it did. (My other thoughts didn't really go anywhere)
- It's interesting that regardless of heating method (water bath vs microwave) that you can still effectively up your yield for a given contact time.
- I've never (or to my memory) seen anything on volatile loss vs flow rate. Is there anything published you can link to?
- I'm not really proposing that people microwave coffee in a meaningful way - it's just a fun experiment, where I was surprised to stumble upon the effect, and more surprised that it didn't make the coffee taste at all bad. That seemed worth sharing...
@@jameshoffmann Ah sorry, I miss-listened regarding the rate in which the cold shot ran. Without sounding like "I can't be wrong", this new data does make some sense. Cooling the coffee does make the mode size of all particles smaller so it going slower is the expectation. This in combination with the retention in volatiles evidently results in a marginally slower shot.
The fact your coffee yield goes up with T is an argument for extraction being kinetically limited - higher average T, higher EY. But what EY do you want, that is the question.
Re volatile loss vs flow rate - no data published that I am aware of, but certainly true from my experience in large scale batch reactor setups. I guess someone will publish on this at some point??
And finally, of course, I know you aren't advocating for this ;). I'd like to show you an equally crazy idea I've ambiently been working on. I wonder when I will see you next.
Christopher H. Hendon That’s easy for YOU to say...
@@jameshoffmann: I am not a researcher, would be the effects of using colder beans for espresso, seeing that shots run slower that way, therefore dissolving more solids?
Sitting here with a 25.6% avg extraction, What I do think is that the difference have to do with co2, non microwaved beans during bloom smells of co2 very unpleasant microwaved beans don't have that smell, It's just instant pleasant aromas during bloom. Very nice James thank you for sharing
Interesting! Thank you for that info!
You may very well be right about CO2 being the secret, but I'm not sure how you're "smelling" CO2 during the bloom since it's an odorless gas
Hey James, I would appreciate if you make a video on how different size cups and materials; paper, ceramic, porcelain, affect the taste of coffee.
It's weird hearing james swear.. O.o
He feels like that one super wholesome friend who really just enjoys sharing his interests with you
I'm just confused what Ukraine ever did to James XD
Tried it today for pour over, there were so incredibly few fines that it drained insanely quickly, and I had already ground finer anticipating that. I might be able to go a whole setting lower with my Lido 3, which would be the finest I'd ever attempted on a pour over. Even today with the "too coarse"/fast draining brew, I am getting good flavor, the sweetness is amped up. Yesterday I tried it with the Flair and maybe over compensated on grind, going too fine and sustaining 10 bar, but it tasted good - again, amped up and syrupy sweetness. Starting to see a trend?
🤣 You tell that train who's boss..
James, please put clips like this to the end of every video (if you have any funny scene from raw videos of the episode) :)
Very interesting indeed.
My hypothesis as to why this happens is as follows:
Every grinder crushes the beans to an extent. The sharper the burrs, the less that happens I would guess, but it still happens. The crushing makes the beans break apart in places that they might already be weaker in, which produces fines. You can try that by cutting a coffee bean in half; even with a very sharp knife you will get many small particles.
Now, if you heat the coffee beans, the moisture in there in there spreads through them, making them softer and more elastic. Thus, the burrs have an easier time actually cutting the beans, and less "shattering" occurs, which leads to less fines being produced, and thereby finally to the ability to grind a bit fine and extract more.
I'd be curious what you guys think
This makes a lot of sense to me.
I was going to write a similar reply. I think by heating the beans, the oils are dispersed more evenly
My home grinder is crying for a burr replacement and landing on this video seems like destiny. I'm totally trying this out on my next drip.
I just woke up to thinking about coffee roasting then turned on the computer :)
It seems to me old dry bread in a microwave brings it back if nuked for very short period of time by adding some moisture. An oven seems to do the same. I want to try this with some old dry (carbonized) toast and see what happens.
I do wonder if its the oils in the bean or humidity in the air that is effecting it most but then heat may make the roasted bean more pliable/elastic. I notice dark roasts leave a lot of sludge when using a French press so I will have to see what happens by warming the beans with and without a small amount of humidity in a sealed bowl. I just looked this up and think it may apply. watch?v=YPNcTIauATw
It's just a freaking cup of coffee.
Really interesting video James. Are there two things happening?
1. Heating the beans accelerates de-gassing - which is why you aren’t getting the same affect post-grinding
2. Warmer ground coffee allows the water to flow through quicker
You're on an awesome streak james first the v60, then tasting, now this 👌🏼
Alton Brown from the Food Network Good Eats program has an episode ( from some years ago ) where he recommends to warm up the coffee beans before grinding. This "reactivates" the essential oils and brings them to the surface. I do this now with a dedicated kitchen pan and the coffee tastes much much better. I warm up the beans for 5 min... constantly moving and stirring the beans in the pan, fine grind and brew.... fantastic results every time
It’s (current year) we freeze, boil & nuke coffee now 👌🏼
Freeze boiled coffee
The intros to these videos are so captivating, thank you for putting the effort you do into them!
The one thing missing is some kind of microscopy on the heated/cooled beans, the partially ground beans and the end result. That may give a clue as to what is happening and why the end results are different.
I know a 'ffs', a 'gfy' and now I have a 'fyt'; thankyou James.
To minimize grinder static I used to slightly moisten my beans using the wet spoon trick. But when grinding for espresso I had infuriatingly inconsistent grounds retention in my Graef CM800. Since I weigh both before and after grinding, this frustrated me enough to revisit my Hario Skerton hand grinder. However grinding for espresso with the Skerton is maddeningly time consuming.
But lo and behold, microwaving the beans rewarded me with stable and minimal grounds retention and as an added bonus it improved extraction dramatically.
My wife often thinks I get a bit too silly/nerdy/obsessive about coffee, but thanks to you my coffee making skills have improved immensely.
Thank you James! I hope you have a great day.
I've been watching your videos for a while now, I've been a coffee drinker for 20~ years and only now am I starting my journey into becoming an espresso enthusiast. You inspired me to tinker and experiment with what I've had - V60 pour-over kit - to get the best coffee out of it. But now I'm looking to get into the Espresso world - I was lucky enough to find a '91 Gaggia Baby that was treated well to go with the ROK manual grinder I purchased. Thank you for making the sciences of coffee fun in a very humble and direct way, I really appreciate your humour and you've become my go-to for coffee knowledge. I look forward to more Weird Coffee Science from you!
I see your bottle of Kahlua in the background.
That reminds me, I might just have to make some homemade Kahlua & cream soon! 👍😎👍
I see a few people saying about extra “roasting” your bean in the microwave. Microwaves don’t work like that. How a microwave works is by simply agitating the water molecules in the bean to heat them up and in the process would be making the bean softer from the inside out. Just think this we have all done the following at some pintbun time, you get a piece of stale bread put it in the microwave for a few seconds to get it up, but it come out soft and fresh. That’s because the water molecules in the bread have been agitated and heated to to make the bread appear fresh.
The same would be happening to the coffee beans.
This is super interesting! Just tried with a v60 and it reduced my draw down time by a fairly significant amount. I also think fewer fines were produced when grinding. I didn't however, allow the ground beans to cool down so I did taste some of the unpleasantness/over extraction that you mentioned towards the end of the video. Definitely going to experiment some more.
That intro was amazing! It almost looked like a Kraftwerk music video!
How does this affect, if at all, other types of brewing coffee (chemex, drip, French press, etc.)
Why don't you try that? If you brew with those methods, that would be good to know.
I'm going to test this with my Aeropress, but I'm also very curious. It would be nice with some input from others.
Anybody try it with a French press yet?
i would have tried doing 1/3 hot grind 1/3 cold grind and 1/3 room temp grind in the same cup to see if you broaden the flavors across the entire spectrum.
Dang 3am. I want my coffee now!
I'm actually kind of surprised that someone didn't mention a hot-air popper. It would take a few trials to figure out how long to 'pop' the beans, but it would work quickly--surrounding them with *LOTS* of really hot air--and can sit in the corner of your coffee cupboard without taking up a lot of space.
I tried this and it was night and day, the coffee changed completely. This may make a small difference if you have a good grinder but I have a Krups gvx that I bought 15 years ago and blasting the coffee beans 2x 30sec in the microwave brought flavors that I did not know my nice coffee had. Brewed with french press and everything was weighted and timed so no possible error. Maybe James should revisit this and see what difference it makes with different grinders.
Today ground hot beans ( cooled down just a tad), microed 1 minute on high in a ceramic cup. Did my Clever in the brewer into the nuke box to maintain brew temp pour over method 2 mins on low after grinds over hot water method (took a good minute of stirring to sink the grinds) so basically a 3 minute brew at boiling. This time did not get a "flat bottom" grinds very much stuck to the sides of the filter paper. AWESOME CUP!!!!!
This is old but hope you see this. I have a coffee TRUCK. Not a shop. My biggest issue is that the temperature and humidity in my truck vary wildly as the day progressed and I have to constantly adjust my grind and dose to keep a consistent shot. The hotter it gets, the finer I have to grind and the dose changes from less to more from 16 to 18 grams. It's a pain in the honey. My roaster thinks I am crazy, but of course he has a regular shop where the temperature stays constant from the moment he opens to the moment he closes.
French Press by Bodum using plastic frame, used for Brewing
60g whole beans frozen in Ziploc for freshness a la George H.
Sealed ziploc put in microwave with warming coffee cup full hot water. Microwaved until beans warm to touch.
Ground in Rocky set to 20.
Put in preheated French Press, which half filled boiling brew water, vigorously stirred, adding remaining Litter.
Microwaved at 4 minutes to keep brew temp up arround 93C. Poured at 10 min total brew time.
Fully extracted, like dark brown velvet covering on memory foam pillow.
Roast: Medium Dark, not surface oily, not dry beans, blend Central & South American Arabica from altitudes greater than 1200 meters.
Brew water ppm:150;10;10 Ca, Mg, CO3 a la Monika K.
My better half liked the coffee black for the first time!!
I liked the coffee black from hot to tepid; and it also made a great " strong coffee ice cream flavor with heavy cream and stevia; Keto either way.
I love the ability to independently control variables using French Press. Grind size, brew time, temperature independently controllable. As are brew water Ca, Mg hardness and CO3 buffer.
I have begun at a grind size that also works for Venus Bialetti on my induction plate.
This grind size is about 100 micron radius, as suggested by a video on maximizing extraction fraction.
This brew water starting pH 7.69 and brew is pH 6.34.
Love coffee science!
Don
I recently made the mistake of purchasing roasted coffee beans from one of my favorite local coffee shops; the shop sells fresh, but Amazon delivered comparatively (over 2 months after roast) old / stale beans; the only way I could tolerate those older beans was to first microwave them for 4 mins @ 50% power (20g spread out flat in a large 4c pyrex measuring cup) … flavor was sufficiently rehabilitated
fyi - my brew method is Flair 58 LE, with Goat’s Arco hand grinder
Really I have some "stale" beans to try this on.......That's pretty big.
Yes.........I have done this and similar for pour over.
This experiment tells us that the temperature of the room matters a lot when making coffee.
Thanks for doing weird stuff with coffee. This is actually very interesting.
I use a Moka Pot and have always enjoyed the taste of dark roast beans that are keep in the freezer but I have never thought about heating them in a microwave. I am going to have to try this now. Over the weekend I ordered an espresso machine and can't wait to start experimenting with it.
Mmmm, i live in Qatar and the temperature here reach 56 degrees, so my question do I still need to heat the beans ? 🤔
The solution is easy. First you package the beans frozen in cup to full pot sizes.
Then the fun part is a custom grinder that has a heating element that you would put the grounds into. Slowly bringing the grounds to temp then it heats the grounds to the desired temperature and to texture. Think easy bake oven with a digital clock. it could connect to coffee maker of proprietary design. Flushes itself with water then air.
Consider that heating dries the beans and getting cold beans out of the freezer into the room temperature causes condensate, which increases the moisture content. When I get fresh beans from the local coffee shop and pull fresh shot the same day I get one flow rate. After the beans sit at my place, which almost always has drier air than the coffee shop due to heating or air conditioning for a few days, then I get a very different flow rate. That of course with all the other variables like grind size, etc being equal.
I did a variation. I have a microwave that is also a convection oven. I normally use the 100 degree Fahrenheit setting for raising bread dough. So I "raised" my beans for 5 minutes and put them through the Rocky grinder. The result was much less clumping and a fluffier grind. I reduced the grind setting one notch. A dark roast is a little sticky due to caramelization of sugars during roasting. My medium roast is not sticky. However, while my fingers do not recognize the beans as being sticky, the grinder seems to disagree. Coffee beans are notorious for being able to pick up flavors. It appears they also are somewhat hygroscopic and a brief stint in the oven dries out the surface moisture that they pull out of the air. The grinder definitely likes the drier beans better, The puck is wetter at the end of brewing due to the finer grind. My bottomless filter basket shows no spatter and more even flow. A work of caution here. I do things differently. 23 grams in the basket gets brewed then divided into two 10 ounces mugs which get diluted to make a total volume of 20 ounces. This is coffee for 2 made by Miss Silvia. This works for us and is a large improvement over our old Kurig which we gave away to a worthy cause. Miss Silvia is stock except for the addition of a PID temperature control. The NotNeutral mugs fit under the bottomless filter, but not the standard filter basket. The PID is temperature only, preinfusion is done manually with a stop watch. Our first Kurig died when the electronic display quit working. If my stop watch quits, I can replace it on my next trip to the grocery store and it will cost less than $10, If the PID dies, I can revert to factory default, or replace the PID which I installed myself. I can get parts for Miss Silvia. No more unrepairable coffee machines for us. However, I can't brew coffee and talk on the phone simultaneously and I wouldn't want to insult the beans by doing that.
ANOTHER SUCCESS. microwaved some fine whole beans 30 secs on high (plenty hot also let cool to around body temp b/4 grinding this time) this time in a plate for better heat distribution than a mug, then in Clever basic bloom pour over then 2 minuted low in micro to keep brew temp at/near boil. A FINE CUP INDEED. Surmise the at boil brew impacts brew taste more than the brief nuking. Hard to know since I don't have it in me to do 3plus solo cuppings.
It really worked for me as well. Especially noticable difference with cheaper ceramic burr grinder.
For those of us without a laser thermometer, how long did you microwave a dose of coffee to get it to ~60C?
Microwaves are a bit different, so results may vary. An IR-thermometer like that costs from about £7 - and you can probably think of other uses for it as well :)
If you have a milk thermometer, perhaps you can use that in stead?
I was wondering the same thing. Maybe James can do a review of IRTs.
For 30g of beans, at about 1000watt microwave - 25-30sec.
Ground my coffee, then microwaved grinds then brewed clever pourover grinds atop hot water method today. Results........EXCELLENT CUP. Shoot looks like I accidentally deleted details of my 1st microwave beans cup also tasty. Have only had two mishaps......burned beans once, and the boilover debacle below.
I gave this a shot - punsssss. It made the most difference with stale beans for me. I could extract a bit more flavor and produce less bitterness. I still don’t think you need to cool the beans before pulling the shot though, especially if you pre-infuse.
There have been papers written about it. Easy. Coffee becomes more brittle as the temp of yhe bean goes up. That leads to coffee particles being more inconsistent in size and less uniform which also leads go faster shots. The cooler the coffee is, we will get the opposite effect. This is how the whole freeze your beans craze started, it mainly leads to more uniform particle size, tighter density in the puck, longer shots.
I don't have a way to measure the temperature, so I just microwaved my beans until they felt "strongly warm but not yet hot".
Grinding with hand grinder, the feeling definitely changed, it feels like grinding something a tiny little bit more... "elastic"? I'll try to make beans even hotter next time and see if there is any difference. Will update when beans cool down, gonna make some stove moka pot coffee.
It also made me wonder, if anyone working at coffee roasting place ever tried grinding coffee immediately after roasting, when it was still relatively hot? Or let it cool only partially and just toss it in a grinder? Then, when roasted and ground coffees are cool, grind some more roasted coffee, brew, and compare both?
Edit: Inspected what I ground, and I was honestly surprised! A lot more bigger pieces (but the desired-size big), a lot less smaller pieces and fine particles. Also, I should have measured brewing time, but I swear it was a bit faster than usual (for this 3c size moka pot). Waiting for the coffee to cool down a little, will update on the taste.
(Beans used: medium roast Brazilian beans with milk chocolate/nuts/cocoa flavour profile. No acidity.)
You should try cashew coffee! I had it this morning for the first time and was very impressed. It tastes almost the same as an almondmilk latte but is just freshly brewed coffee and cashews mixed in a blender.
While living on Hawaii Island I bought green Kau coffee beans and roasted them in my oven I let them cool to the touch and ground them The coffee was stunningly delicious.
Today's "microbrew" nice Ethiopian beans nuked 1 min on high (3x 20s actually to be scorch safe) Ground stil warmish. Brewer nuked 2 mins on power level 20 (next to lowest on my box) Again smells extra yum ground. Did grinds over water method. Again super heady/bubbly/bloomy so stirred top cafe layer quite a bit. Brew poured through quite quickly, nice "bed" few side clingers. Smells wonderful. Now for taste its at chosen temp.....did i brush my teeth.........yes.....EXCELLENT.......no sign of over extraction, I think I'd have liked to have brewed it 3 mins. I haven't had this same bean in 2 or more days so can not say hella better than sans bean preheat, and I've brewed it several ways. Its just VERY VERY GOOD. Weird????? Yesterdays made similarly was extraordinary.......but those were extraordinary beans to start with. these are far from meh....very good. I've had them maybe 10 days stored well.
I now use this hack every day. The first time I tried it my wife complained the coffee was too strong. So, I'm using about a tablespoon less beans per pot. This also solved the problem of grounds from frozen beans clumping on the inside of the grinder I guess because of condensation. Even for our boring old drip coffee, usually Aldi's San Pablo Estate from Peru, this seems to have made a significant difference.
I currently work for a coffee kiosk company and the first time I noticed this temperature phenomenon was a couple days into working for this company. The shots in the morning were fine and consistent then mid morning I found myself struggling to keep the shots consistent. Every single pull yielded a different result. Then I noticed the sun was beating down on the grinder. I put my fingers in the hopper and, sure enough, the beans in the back were much cooler then the beans facing the sun. I stuck a thermometer in and there was a 70 degree difference between the front and back. It made so much sense because things that are warm are more mailable than things that are more cold and brittle. I made a makeshift hood and the temperature stabilized as did the consistency. The most annoying thing is that some kiosk managers don’t want you to ever adjust the grinders 🤦♂️
Paul Aspen correct in you assumption. If you work in an air conditioned environment where the ambient temperature and humidity is constant there is no need to adjust your grinder. If you Coffee station is out in the elements you’ll need to adjust your grinder depending on the hour of the day, the humidity, and the ambient temperature. This all affects the grind of your bean, and your grinder should be adjusted accordingly to suit the surrounding elements.
Could it be the Oil in the bean ? sort of re-hydrating it slightly, giving it that freshly roasted flavor again.
I rewatched this video 2 years later and I now realize the f*** you train at the end! Brilliant James, i loved it!😂
Warming the beans will make them softer and less brittle, so the grind will be more consistent. Being less brittle also means less shatering, aka "fines"
Grinding also makes the larger masses smaller which is contributing to the greater heat absorption. Not to mention the friction and pressure of grinding itself.
wow, what a coincidence... about a few days ago me and my friend doing some 'coffee hack' by microwaving some coffee beans at the office...😂
Some wild guess:
Microwave vibrates water molecules. It frees the water molecules from the coffee-bean cells so the beans are dryer. It may makes the bean cells' moisture uniform. Thus, the grind produces more uniform particles.
Also, despite the water molecules, generally hot things should be easier to be cut/broken because their particles have more potential energy & don't really "mind" to separate from each other. So, it's easier to be cut by the grinder & the result is a more uniform grind.
The physical chemistry of the coffee brewing is just fascinating. I think it's not only the temperature but the humidity content in the coffee beans, maybe that present quantity and state of the water molecules contained is affecting the quality of of the flavor of the brewed coffee. Why? Well microwave's heating may have those water molecules in a more excited state and disolving part of the aromatic and other soluble molecules inside the coffee beans. Microwaves are known for being capable of uniform and efficient heating so maybe that mild heating and posterior cooling before grinding makes the coffee beans more "juice" wich in the end could be the difference in the taste on the espresso cups. This is a really fascinating topic. Nice video and thank you, the topic is surely worth of a series of more experiments after all there are more variables to consider.
This is becoming the greatest series of them all
It's kindy funny that all that years I heard that an advantage of burr grinder over the blade is that the former doesn't heat up grounds while grinding. Turns out it may actually not be bad! (use burr grinder though not to avoid heating up the beans but to get far more consistent particle size).
Is there an easy way to heat up beans without microwave that can be incorporated to a morning routine?
For coffee or espresso? I guess with an espresso machine you could put a little tray with beans on the cup warmer on top while it's heating up (except, in my case, I got a pavoni and no microwave, so I guess I'm out of luck ¯\_(ツ)_/¯)
@@tobymarol7329 I am making pour over at home (home espresso turned out to be too much of a time consuming hobby for me :) )
I might test it, but I have a few strange questions... one I want to know what it will do if I put coffee in a steamer, like my rice cooker, another what will it be like if I try to roast my coffee in a slow cooker? What will coffee taste like in the slow cooker like stewed coffee? Hmm Nothing seems to be a good idea, but I am curious.
This has gotten way to complicated, just cover my beans in chocolate and I’ll chew my coffee.
As Marco Pierre-White would say, it's your choice.
james could make a 20 minute video comparing the different types of hand crafted chocolate that are better suited to pour over beans and chewing on them
@@sebaba001 I’ll second the idea of finding the best chocolate coated coffee bean as a video concept. That could be really interesting, which chocolates, and which beans, make the ultimate chocolate coated coffee bean.
You do get quite a caffeine kick that way!
This actually makes perfect sense!
Freezing the beans would make them more brittle during grinding, and therefore more likely to break into inconsistently-sized particles.
Heating should have the opposite effect, reducing the brittleness, and creating more consistency in the grind size.
So expensive grinders that don't heat the grinds up as much are actually worse?!
I use to have a high end stereo store.
Lots of listening in our reference room.
This was in the late 70's, early 80's ( a very volatile time in the stereo industry}.
Bottom line, is that people frequently preferred the "different" to the more accurate (reference).
I wonder whether some of that isn't going on with our coffee tasting.
Just saying.
Great video as always James, extremely interesting and opened my eyes to something I never would have even considered.
How did it taste after heating it up in the microwave then grinding?
Better or worse?
I think it would actually be pretty simple to replicate commercially, given the important factor is heating the beans, and not the microwave interaction... I think just pour it into like a jacketed hopper that is kept at X temp. grind per order, either tamp and wait, or par grind as needed.
I love your scientific approach!
I actually have thought the idea of microwaving coffee beans would work, and had done it, but didn't experiment much with it - I didn't know what temp they were before grinding or brewing, etc. So I'm really happy to see you went the next steps with this! I'll play around with it more myself to see if I can get a noticeable, reproducible improvement in flavor that's worth the added bit to the process.
As a coffee enthusiast, one of the things that I like about it is how different of a food it is, but sometimes I wish we would spend effort into trying to make "acorn muffins" or "maple tree seed tea" or even a cinnamon substitute made from entirely pine cones. #nuts
Tried heating the beans up.
I think my coffee tastes better?... I'll keep doing it.
The static that I experienced with my Lido hand grinder is no longer an issue - an unintended result of heating the beans - THats Gold son Gold I say...
I experienced the same with the static. No more an issue.
Hey James, as always, love your videos. Thank you for all the information!
I was wondering whether you have any interest in making a video on decaf coffees. I drank coffee for the caffeine for over a decade before discovering specialty coffee, and for the first time, I'm completely infatuated with the taste of coffee. And I'd love to find great decaf coffees that would let me enjoy that kind of taste well into the evening. Thanks again. Cheers!
You can't have decaf beans tho can you?🤔 The caffeine must be extracted somehow and that only works if the coffee is already ground imho...
@@mikeymike437 www.amazon.com/gp/product/B0771T5RS8/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1
Maybe when warm a few hits and they get punched into pieces - like kicking a cake - as you do - and then chomped easily to size with no hassle. But when cold, they bounce around between burrs many times, collecting a multitude of little fractures, then getting pressured to cave in, but resisting , producing more and more fractures, like kicking a glass ball around - which contribute to produce overall smaller grind and shatter when chomped down. So in short - I think it's fractures.
IF that's true, I think you'll see MORE crema, because the chunks will remain big, so retain their gas.
Never microwaved the beans, but when I used the porcelain and glass v60 I used to spray them with water and microwave them to heat them up. Worked better than using water from the kettle
For some weird reason...I totally love that intro music!
I was born on an island where coffee beans cherries could be picked and on the side of the road. The start and end of a cup of fresh coffee being grilled in brown sugar and pounded to powder and turned into coffee right in front of you is amazing. of course hot ground beans taste better. they did not have grinder back home but the espresso made there can never be rivaled by modern day espresso makers.
Hey ! I have travelled to many coffee producing nations and have witnessed that the locally available coffee beans suck there with best beans getting exported and locals drinking crap Grilling coffee in brown sugar sucks and is only good to cover bad beans. Never seen a decent high end espresso machine in a 3rd world coffee country with locals knowing nothing about real espresso.
Does this also apply to filter coffee or french press coffee?
OK, added microwaving my two scoops (Yes I know,,, SCOOPS!) for 22 seconds and slowly adding the beans to the grinder rather than just filling it up and letting it go (another of your videos) and the taste has very noticeably improved. Fines have drastically disappeared and the results are far more consistent. I was having issues with occasional higher levels of bitterness. I use a gold metal filter in my Aeropress with a dark roast. 185f.
Like with the water in Weird Coffee Science One, there are too many variables! Simplify!
Didn’t we all learn with the trend of the small spray bottles that water content does have a significant impact on grinding? I feel like the heating is mostly drying the beans which then leads to the described effects. Would be fun to compare vacuum sealed and heated beans (sous vide) with the microwave experiment…
Tried again diff beans 20 secs on high cooled b4 grind. This cup is a bit bitter/ over extracted, but I can not attribute that to bean prewarming. Hmmm
Ok. Here’s my theory. It may be that the slightly higher temperature of the microwaved coffee beans increases the elasticity of the cellulose in the beans. This increased elasticity could cause a narrowing of the peak of the grind distribution or a least reduce the number of fines caused by the shattering of coffee bean particles during the grind..
I can't wait for celebrities to go in on this action too
Next up: Joe Rogan adds DMT to his espresso
Joe Rogan already adds mushrooms ;)
Perhaps the thermal expansion and compression has an effect on the beams as they’re grinded, like a shrinkydink, you can get much more “detail” that you wouldn’t normally get.
We had a pretty engaging conversation on this topic going on H-B right after Chan's WBC presentation. I'm glad to see you investigating it and sharing your thoughts as well. I played with this a lot, and it certainly helps with pushing bright sours into bright ripes. It really enhances the assertive fruity powerhouse coffees in my opinion, but for tamer coffees, i.e. pulp natural Brazils, most Indo's etc, not as much.
Here's a suggestion you might like to play with and report back. Flip the script completely on this experiment, but aimed at a different target. Take a darker roast, a blend, anything that's seen second crack, and do a pour-over brew session that begins with a simple plastic bottle of water chilled in the fridge, to completely pre-wet the entire grounds bed before then proceeding to extract with whatever temp off boil you prefer and report back. It might REALLY surprise you.
I'm not going to dump forum links on someone else's social without permission but I've written about that too.
Great video!
Please dump links here! We’d all appreciate it
@@jameshoffmann www.home-barista.com/tips/sous-vide-espresso-extraction-wbc-finalist-dawn-chan-kwun-ho-t35328.html
And my method for a cold start for dark roasts noted here, was inspired by and credit goes to Lucio Del Piccolo and what he shared with the coffee world in regards to cold starts for mocha pot brewing.
www.home-barista.com/brewing/cold-water-start-for-dark-roasts-t53568.html
I have yet to find a darker roast that didn't benefit from this little trick.
@@jameshoffmann And Lucio Del Piccolo's discussion was circling around the concept of simply pre-wetting the mocha pot bed of coffee before beginning the brew. I took this to the next logical step when applying it to brewing darker roasts. Both center around a simple concept of a heat soak. Starting with cold water and forcing the brew temp to be exaggeratedly cold towards hot from the beginning really does some fascinating things that remove the nasty distillates or harsh roasts notes in darker roasted coffee. This method honestly makes me love darker roasts a lot more than I used to.
www.home-barista.com/brewing/how-to-improve-your-moka-pot-coffee-t48638.html
I've gotten more and more into coffee in the last few years and it's become a real passion of late. And I've found these videos super interesting! I'm going to try this. Thanks!
You should make a discord!
It would allow you to make a platform for people to discuss coffee
Omg no. 4:16 He swirled the shots instead of stirring them!! Just finishing watching the don't swirl your espresso stir it with a spoon video.
Hearing James say "fuck you train" even if censored, is still a shock
I had two drip machines, 1 cud brew 6 cups, the other 2 cups.
Trying them both with same amount of water and same amount of the same coffee gave me 2 very diff result.
Coffee from the small machine came out much more delicious.
The only noticeable diff in brewing was that the small machine took longer to brew the same amount of coffee. Maybe 12 seconds slower.
I appreciate Gareth as an addition to the Hoffman cinematic universe
Does microwaving maybe dehydrate the beans somewhat? Is there a difference in mass before and after microwaving?