Weird Coffee Science: The Hard Bloom
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- Опубліковано 1 жов 2024
- This is the first in a series of videos where we experiment a little with something weird in coffee. To get 10% off from Squarespace, then use: www.squarespac...
Before you ask (if you happen to read this) the next video on the channel will be the V60 video, sorry for the tease...
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Making my morning coffee looks more like I'm cooking meth now
@Sam 2018 Ever try making meth in a french press? It's the worst.
Haha. Breaking Bad's sequel, "Breaking Crust".
James' Baby Blue Mountain coffee is 99.1% pure. Fun fact: He makes his coffee and these videos wearing only tighty-whities.
@@ericpmoss Breaking Crust: Smells great
atleast you didn't say "my meth cooking looks more like i'm brewing coffee now"
A month ago I was going along happily just brewing my coffee. Now, since I stumbled across your channel, I am sitting here looking up how to test the hardness of my water, running triangle taste tests, measuring the consistency of my grinds, and even home cupping. WHAT HAVE YOU DONE TO ME?
hurdlingelephants I think he might call it education! 🧐
Relate to this so much 😂
Same here. God I miss those times where I could enjoy every kind of coffee, even instant coffee. Ignorance is bliss.
Same buddy, he fucked my life up. But I still love him and his videos :D
I agree with this comment. Now I am never happy with my coffee ☕️. Bailey’s seems to balance it out though no matter how hard or soft my water is.
Laying in bed about to go to sleep but wishing I could just stay up and experiment with coffee all day.
Same.
Same here. Excited for tomorrow morning
Same here
So, so often.
Laying in bed, or lying in bed?? Hmmmm
Hello James,
I think you have a very interesting experiment here. I am glad that at least some coffee experts are willing to test assumptions and shake (or break) old ideas!
I believe the hard water bloom you observed has more to do with the pH of water than it’s hardness. This would be an easy one to experiment with, but first let me explain how I reached this conclusion.
I am a chemical engineer and I have spent a considerable amount of time developing a process to convert biomass, such as wood, corn stover or bagasse, into more useful materials. Coffee (green, roasted, whole bean, ground, etc) is biomass too. All biomass contains basically the same stuff: cellulose, hemicellulose and lignin. There are other things in it, and to be sure in the case of coffee these other things are what makes coffee distinct and so flavorful. Yet, one-fifth of the mass of coffee bean is lignin.
I did a series of filter-extraction experiments on lignin, which I had previously purified from woody biomass. It was clear that using water that was more alkaline in the extraction caused a dramatic blooming effect (swelling of grounds). In fact, a small increase in pH caused filtration to nearly stop (lignin became impermeable). On the other hand, neutral or slightly acidic water filtered through ground lignin without a problem.
Lignin is a complex material that gives plant life its structural rigidity and protects it from the elements. I believe alkaline water makes lignin partially ionic, completely altering its filtration properties. Water hardness is not the same as water pH, but it is correlated, with harder water being more alkaline (higher pH). I would speculate that extracting coffee with hard water seems to increase blooming not because more CO2 is being pushed out of grounds, but merely because hard water affects the physical properties of coffee that have little to do with flavor. Indirectly, hard water makes filtration slower, which could lower the quality of the resulting cup of coffee.
Cheers, love your videos!
Excellent comment! Thank you!
Thank you for sharing with us your experience and professionality. It always feels exhilarating to be able to explain what you observe with scientific experiments.
Thank you for your comment!
Why would there be no difference then in the experiment with an extra 100ppm of bicarbonate? Would that not have a dramatic effect on the pH therefore causing more bloom in the 250ppm test?
Awesome comments and response!!! Your scientific insight not only reveals what is taking place in this experiment, but also how our human misconceptions can take us in seriously wrong directions.
'...the next video on the channel will be the V60 video' *screams in disbelief*
Right??? I'm so excited for this, I've been waiting for it for so long!!!
Thebular1337 I‘m not even in need for a pour over tutorial, but I‘m still hyped up thinking about the release given that we‘ve all been waiting for half an eternity. I guess Jim must be about to break UA-cam with that 😂
TETSU KASUYA IS KING!
To be honest it turned me on as James held the kettle ....
*screams with pleasure*
Noticed James hiding his bandaged finger and now I can’t unsee just how well he hides it throughout the entire video. What a man!
You monster.
You should see his wife when shes pregnant lol.
@@jaimep3432 what a weird comment
His left pinky?
Came to the comments section specifically to see if anyone else noticed this too!
A fairly sciency answer could be ionic strength I.e. in hard water there are generally more ions.
My correlative hypothesis. During the blooming process some CO2 release from grounds becomes dissolved in the water prior to off gassing and some CO2 remains dissolved. The presence of other ions in the hard water cannot be displaced to gas and inhibit CO2 solubility making it off gas faster I.e bigger bloom.
This could potentially explain the acidity change as well less dissolved CO2 could result in less formation of carbonic acid.
Thank you for the information, i tried both the procedure with my Bedhatu Ethiopia, and with hard water bloom it mutes some of the acidity and also the texture and gives me a lower tds compare to the soft water brew.
@Parker Lindsey Interesting. I thought the water hardness wouldn't affect the gassing off of CO2, but instead helped form a more stable foam. I wouldn't worry about the purified water; the osmotic effect is not nearly as dangerous as the popular stories say.
Thanks for the insightful comment !
This thread is great.
Maybe a bit outdated thread... But I find this theory quite convincing. I specifically think that the concentration of carbonate ion is determining.
When CO2 dissolves in water, it forms carbonic acid, which (in my view) is one source of acidic taste in the coffee.
H2O + CO2 H2CO3
However, as hard water already contains a greater amount of carbonates than soft water, the equilibrium of this reaction is shifted more to the left side of the equation. That is, CO2 released from the coffee cannot dissolve in hard water to form carbonic acid.
Regarding the experiment at 2:00, I guess150 ppm of bicarbonate was already enough to massively shift the equilibrium to the left. According to one paper, the solubility of CO2 in distilled water at a room temperature is about 77 ppm, when the gas contains 5% of CO2 (which is much much greater than in the air!). The solubility of a gas generally declines with increasing temperature, so I believe that the actual solubility of CO2 under the coffee blooming conditions is much lower than that.
James, the way you “set up” the brew during your ad was pretty cute. I would’ve enjoyed a bit more spoon sorcery, but this vid was still rad.
Call me a conspiracist but I'm beginning to think that James' spoon conjuration was just a big hoax.
Definitely more spoon sorcery needed
My old man worked in marketing for a coffee company in San Francisco in the late 60s right out of collage. They were making canned ground blended coffee, but the executives enjoyed drinking fresh ground single source coffee and blends to experiment with the flavors. My dad suggested they try selling little one pound bags of fresh roasted whole bean coffee so that customers could enjoy the same quality they drank in the office and he got laughed at. They told him the unwashed masses weren't sophisticated enough to appreciate coffee in that way. Now look how we buy coffee.... True story.
Another video with dope music from James the Demystifier
As a control specifically for the bloom with harder water, you could bloom with softer water, and add the volume of harder water immediately after the bloom. Extraction between the two brews, and acidity of the total volume of water should be comparable, so then it's just the bloom.
This is a great idea!
James Hoffmann pretty sure you knew this already ; )
@@renix3968 simp
Everyone: Please pour over video.
James: ok, ok, pour over basics: Bloom... Oh boy...
I'm only 10 seconds in and the shot of a guy gently wank1ng a coffee bag made my day :-) - 0:10
Turbo Mini TV I didn’t even notice that when I watched this video. Just lost my breath from
Laughing so hard!
Great video - but I was strangely drawn to the plaster on your little finger of your left hand which you then try and hide during the rest of the video.
Same! Came to the comments to see if anybody else felt similarly. It disappeared quickly and was well hidden for the rest of the video
This is definitely one of your best uploads. The editing was superb, the soundtrack was beautiful, and the way how you threw in your ad in the "setup" process was genius. Proud to be a patron James, keep up the great work!
The coffee industry in 2030: all espresso machines have two water lines and shots are pulled using "hardness profiles"
Yeah and you can choose your water from the menu/counter
I started following your videos after you confirmed my position against swirling espressos. I am learning a lot with your work and curiosity. For the last three weeks, I watch one of your videos while I brew a pour over for breakfast. Thank you!
What's that about not swirling espressos?
Care to share?
@@rbmanb Swirling doesn't mix the espresso as well as stirring with a spoon, and it makes a mess. That's the gist of it.
This makes sense because the acidity in coffee is probably reacting with whatever pH buffers that are contributing to the hardness of the water.
Edit: Lack of acidity confirms my suspicions, the extra bloom is more than likely a byproduct of the acid-base reaction that is taking place with the coffee and buffer.
Here's an idea! One of these episodes could be a collaboration with Cody's Lab or NileRed or someone of that nature, that would be awesome!
Also...you might get a load of new subs, the amateur scientists who watch those video, I can guarantee, are avid coffee drinkers ;)
I like this idea!
right off the bat James, hard water is going to affect PH which in return affects acidity, so there's part of the answer as to why one had more "acidic bite" over the other.
Definitely a possibility but not a certainty. Hard water doesn't automatically mean pH greater than 7. You can have a fair amount of dissolved Calcium in water with a pH of 5 or 9. If the calcium in his hard water source is from dissolved Calcium Carbonate, then that would indeed increase the pH and reduce the acidity. He should do some analysis on the water to see what's actually in it instead of just saying "hard water"
almost relieved to hear after many years brewing with soft Edinburgh water and being vaguely concerned it never seemed to bloom like the youtube videos 😂
... Great intro btw 👍
1. Hard water bloom, hard water brew
2. Hard water bloom, soft water brew
3. Soft water bloom, hard water brew
4. Soft water bloom, soft water brew
5. Mixed water bloom, mixed water brew
6. Hard water bloom, mixed water brew
7. Soft water bloom, mixed water brew
8. Mixed water bloom, hard water brew
9. Mixed water bloom, soft water brew
10. Finished :)
x5 aaaand randomized
Squarespace
@Ryan W And your results were?.
I liked this video for two main reasons, 1 - your style and apresentation are very pleasing to watch, good identity I always come back to the channel. 2 - When you apply the cientific thinking into the everyday situation you are making science at its finest, good job.
Every video's intro music just makes you wanna go watch Stranger Things 👌
Love the nerdiness, love the imagery. Oh, and you should consider doing voice work, audio books, etc.
Work with Socratic Coffee. Their science + your delivery and audience = WWWOOOOWWW
yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes PLEASE
YES. THIS^^^
Love the concept! This is like a deeper dive into coffee. I do know that type of water we use could affect brewing that is it. Heard of soft and hard water ('coz I purchased your book, haha) but never really understood it thoroughly. Looking forward to the next episode as always! 😊
all the science and theories aside, brewing part of the video was so beautifully done. really enjoyed it :)
I love all the old footage at the start of this video
Does more blooming foam actually equal better blooming? To me it just seems to say something about the foaminess of hard water.
It's probably the same reason why you need more soap with hard water. Cursory google search suggests different surface tension.
Great question! It really asks if we understand why we bloom. If it is about getting CO2 out of the coffee, then yes - more blooming is good and we should see increased extraction and better taste. In theory...
James Hoffmann I think what Tilman Baumann is questioning is whether a greater volume of blooming foam actually means that more CO2 was released. As he says, it could be that hardness is altering surface tension, making bubbles form more easily. Perhaps soft water blooms an equal amount of CO2, but lesser surface tension doesn't allow foam bubbles to form as easily. A method for measuring total CO2 release is needed.
@@drloko4013 That is what I mean. I don't think more foam is a metric for better bloom.
I feel very stupid now. We definitely need a way of working out total CO2 release...
It's time for the coffee industry to look at gas spectrometry (it's far cheaper than its liquid counterparts!)
James, what if you use a vacuum chamber to extract those CO2 molecules? Look up those multichamber vacuum sealers, where you can, for example, force extra watermelon juice inside cubes of watermelon.
So my guess would be that you would grind the coffee, put it in one of the vacuum bags together with some soft water. You would then suck out the air around the bag, which inflates the bag, dragging out the CO2 from the grind, then equalize the 2 pressures, which forces the CO2 out of the bag, while the grind and water would be forces together.
Link to an example of this: ua-cam.com/video/rYjZl2yPmaQ/v-deo.html
This sounds like a good bit of weird coffee science
Beware of the different is better phenomena.
Interesting suppositions.
James, I think you should start with distilled water and add minerals to it creating some very hard water. Then mix that water with distilled water to achieve any ppm level you wish. Then you can test many different levels of hardness and compare. I use the following recipe:
Potassium Bicarbonate @ 0.1g per 300 grams Distilled Water
Magnesium Chloride @ 0.5g per 300 grams Distilled Water
Calcium Sulfate @ 0.4g per 300 grams Distilled Water
To just say use soft or hard water doesn't work for me, as there are too many variables. I have been using between 100 ppm and 150 ppm water to make espresso, using my Flair Espresso Maker and Kinu M47 hand grinder, and am pleased with the result. I find it amazing what one can feel when using all manual devices, as you don't get the feedback when using powered machines. I roast my own coffee, and even find differences in the espresso making experience because of the roast level or the coffee seeds themselves! With my tools I can dial it in very nicely, but there are still differences even when trying to do everything the same.
This sounds like the more scientifically sound procedure to carrying out this experiment. To have evidence of sufficiency and necessity, you'd need to have trials adding and subtracting minerals.
Argh! I JUST stopped swirling my coffee in the filter and now I see that you do it. What's a guy to do?
I love how you hid a V60 tutorial in here ... swirling the bloom, eh? ... you must have the older V60 papers ... you do! ... the fluff on those grinds is incredible
Love the intro of this new series! Our roastery is in a area of surprisingly hard water (for Dutch standards), but it is coming from high quality reserves of ground water. We filter (and soften) the water going to our espresso machine, but for pourovers, I have mixed feelings. Not all our origins necessarily benefit from using filtered water. But in our case we guess that the filtering is removing "nice" minerals and perhaps flattening out some coffees... but my guess is that we are fortunate and our tap water is high in magnesium and other minerals, but not in bicarbonates. Coming back to your experiment, as a business serving V-60's, we go frequently through the process of blooming and brewing with different waters due to logistics and rush periods. Mostly we refill the kettle with the 95C tap that goes through the filter, sometimes I fill it from the normal tap and let my bonavita do the heating (it doesnt fill nicely under the other tap ;-)). When doing multiples pourovers, I sometimes run out of water after rinsing filters and blooming (with hard water), and I quickly refill a kettle from the filtered tap. Even then, I personally dont notice an improvement. For delicate teas that's another story altogether and we only use filtered water.
Hi James, awesome idea for a series. As a chemical engineer doing his PhD on delicate chemistry this series certainly blends my passion for coffee with my curiosity to discover the chemistry behind it. This particular video touches upon an issue I had while brewing. I live in Portugal in a region with typically softer water, but have been living for the last few months abroad in a region with clearly harder water. Although I didn't notice the difference in bloom volume, I did notice that brewing with harder water does tend to overextract and, additionally, mask the finer aromas of a particular batch of coffee. What is your opinion on this? Your brewing experiment here was certainly interesting, but what about adding a third brew with just hard water and compare the results? I'd love to hear your thoughts on this. Keep up the great work!
Surely added bicarb would interact with dissolution of CO2, no? It would seem to make sense to also test with other softeners (citrate, borate if you're adventurous) and with distilled water.
"Let's uhhh let's do that then" this is the English delivery that keeps me coming back every vid.
We need a fast car chase in an urban European setting in an Italian sports car followed by a Bond like spy having coffee with a bad guy who uses coffee as a cover for his sinister activities yet the prep and serving and drinking of the coffee should be emphasized scenes like the pastry scene in Inglorious Basterds.
I don’t know what a bloom is, so thanks for starting with that.
Could dump the bloom water before brewing the rest.
Really interesting video. I'd never thought about this. :)
That's what I do. LOL!! I definitely notice a diff.
I am so excited for the v60 video!!!!
I would like to try and brew coffee with controlled amounts of salt. Pure water vs. 1%, 2.5%, or 5% salt water solutions.
I feel like James Hoffman fills his videos with as much cinematic shots as possible and I love them
Nobody:
Jeff goldblum lookalike: the hard Blum
Coffee Chaos theory
James - there's a cool phenomena you might want to unfold. Dripping a little cold water in, towards the end of a Greek coffee brew, produces a tasty white crema. I could never understand why. The same effect is also achieved through lightly flicking a spoon around the edges, at the end of the brew. Wish we could chat all day about Greek coffee prep but for now I think this may be a cool angle for your science series.
I love the "nuclear physics" type opening. I like to think at this stage I have at least an OK grasp of cooking, yet making consistently good coffee in small batches continues to be a daily struggle :D
So we go even more geeky now?
Love it!
We have to! That's why we watch James' videos in the first place, right? As well as watching Rao's and Perger's
Did you hear about Water for Coffee: Science Story Manual book? Authors of this book made some research about how different ions in water change the way coffee extracts. There are also some vidoes on YT from authors' lectures.
Dawid Gładysz I know right
What were your soft water specs? Is it the “ideal” water you brew with at your roastery? Or an “extreme” version of soft water as a comparison?
It was an extreme version of soft (but not distilled/pure)
Just a thought, (More like a rabbit hole) but I'm curious to see how the test of combining hard & soft water in different combinations throughout the brew can affect different factors like Density, Roast Level, Processing. Could lead to some interesting results.
This is a great science outreach video!
I definitely noticed bigger bloom/co2 with harder water. For example when I travel to USA there are very hard water in some states. Sometimes I have to downscale the amount of coffee I make in my Aeropress because it "blooms over".
Inverted method: 16g coffee and 240g water works fine until the water is hard and I spill all over the kitchen counter...
Did you use Ca and bicarbonate as CaCO3 unit in second test? And how much amount of bicarbonate used in first test?
In your clip, both high bicarbonate water show very thick foam.
Hi James, really enjoyed this video but I have one major request for future experiments: please taste them blind!
I cringed a bit when you explained the effect that the hard water was having and how it aligned with our preconceived notions of hard water brewing. In the future, if you were to taste the coffees without knowing which one was which, your stated results may be more indicative of the coffees' differences rather than our preconceptions.
Thanks a lot and I'm looking forward to more of these in the future!
I primarily use coffee as a companion to certain things I like to eat with it, breakfast, pastry, etc. I use tap water with drip and our hard water does fine for that, I use a refillable Keurig cup when I need speed, and I have to use bottled water for that, so the latter for just drinking unless I'm pressed for time for using with food
so now I have the hard bloom to play around with, I'm retired so what better to do with my time?❤
James would really like to get in touch with you to help with data analysis and I am a coffee nut! London based. How can I get in contact with you?
There's a contact email on my youtube about page!
Mr Hoffmann, Proper reply. " If I ever run into any of you bums on a street corner, just let's pretend we've never met before"
It’s 3:00 A.M and now Im going to make coffee with “Hard Water”🙇🏼♂️😅
Actually did this type of experiment a while back. I use tap water typically, its a little hard but the TDS and mineral content is very good. I also purchased some of the third wave water stuff to try, out of curiosity. While the water did taste softer and a little tastier in my opinion and taste, it actually flattened out the coffee quite a bit, almost made it duller. It had a little bit of the prickly acidity that you mentioned with the soft water only brew but beyond that it just didn't taste as full. Course I could be just conditioned for the harder water at this point. The hard water just tasted fuller and had a larger range of notes. I will have to try the blooming with hard water and brewing with soft water some time. My real question is does it matter all that much the size of bloom when brewing?
Great video! It would make sense to taste the coffee blind though, to remove the possibility of unconscious bias.
Love this, can't wait to see more. The one feedback, i'd love to see them longer!
This is quite the tangent but while we're on the topic of water:
I once read some blog post a few years ago that you should never re-boil water. That re-boiling affects the taste of it or something.
The thing is, how is re-boiling water from a kettle any different from what happens inside the boiler of an espresso machine?
It isn't much different at all. This is why brewing with espresso machine steam boiler water isn't great, and even making americanos with it are inferior to something from a hot water tower or similar.
@@jameshoffmann What about the water that comes out of the grouphead then? Does the constant bounces in temperature also affect its quality?
@@jameshoffmann it reminds me of the experiment video of Mei Leaf on how reboiled water affects the tea. But Don Mei guessed the oxygen molecule is the answer affecting the "freshness" of the brewed tea. Because for him, brewing tea with 75C from boiled water mixed with cooler water gave him better result than cooled down boiled water. How is your opinion James? Is it because of the oxygen molecule or something else?
Uhm... what is hard water?😂
Water with a high mineral content (or “ppm”)
Google is a thing
Ice
Water with high levels of dissolved calcium ions and bicarbonate. This is typically from water that has passed through a limestone bedrock. Heating the water causing the calcium and bicarbonate to bind too each other and to come out of solution - as limescale that you see on kettles/inside coffee machines. It breaks coffee equipment and often makes coffee taste bad. However, pure water is also bad as it is corrosive and makes bad tasting coffee too!
@@jameshoffmann does your book contain this explanation? I have to stop procrastinating buying your book!
From a chemistry perspective, this behaviour between alkaline and acidic solutions is predicted.
So, while overly simplified, disregarding the exact composition of the used coffee or water,
hard water (usually alkaline) and something acidic (compounds in coffee), yields less acidity (due to conversion to a salt) and will produce CO2.
yeah, That's also what I thought at first. Those bicarbonate in hard water will neutralize the acids in coffee, yielding less acidic coffee brew with more CO2 bloom compared to the ones brewed in soft water
Coffee from areas where the tears of oppressed women and children fall on the coffee plant roots produce a superior brew which normally isn't recognized by commoners but only elite wealthy folk and royalty. As if a spiritual quality is tastable buy those who are gifted in life to have a discerning palate. Commoners lack this just as a dog cannot taste the difference between cooked old dairy cow and filet mignon or Kobe Beef. I've got a Porsche.
Dude, this intro slaps!
Good experiment would be to compare:
Bloom with hard water, then brew with hard water,
Bloom with Soft Water, then brew with hard water,
Bloom with Hard Water, then brew with soft water.
Also might as well do Soft and Soft! So you got basically all the combos to compare. I guess you won't know what's really contributing to what (actually maybe you would?) maybe instead of doing a small bloom and larger pour, split it so it's 50/50 with a good minute pause or so between the bloom and main pour (which are now equal amounts).
Then if Soft then hard is the basically same as Hard then Soft, you'll know it's probably the overall hardness amount contributing to the extraction efficiency and not the hard bloom specifically.
I'm guessing that would be the case, and soft and soft would be under extracted tasting, where hard and hard would be over extracted.
I found in general using higher mineral content (or at least using different Third Wave Waters, vs also pretty hard filtered Tap water) the TWW / Mineralized water made extraction more efficient so I had to lower temperatures to avoid over extraction.
What was the brewer used in this video?
Also, what happened to your pinky?
It’s the Hario V60 carafe
:D I admit I went to the comments to see if anyone else was curious about the pinky
A fascinating premise, James. I look forward to making some interesting observations, if not strictly "good science" tests next time I do a V60. ...Shh... do you hear that...?
*Ground rumbles as the Socratic Coffee folks come stampeding in*
The biggest problem with the test is that it wasn’t done “blind”.
Get 6 cups and mark three cups on the bottom for the "hard" water. Pour "soft" water in the remaining three cups. Then mix up the cups so you don't know which cups contain hard or soft water. Then taste them and set the ones you think are hard water to one side and soft on the other. Then look on the bottom of the cups to see if they were correctly identified.
I'm going to love this series
I wonder if the difference in the bloom is more just due to particulate forming with the higher concentration, and/or is more stable due to the calcium content.
I suggest seeing how the concentration of CaCO3 (Calcium Carbonate) affects the bloom of the coffee. When Calcium Bicarbonate ionizes it turns into a Bicarbonate ion which will probably turn into carbonic acid instead of CO2. On the other hand the Carbonate ion of CaCO3 has a higher likelyhood of turning into CO2.
Forming of Carbonic acid from Bicarbonate ion
HCO3- +H30+ ----> H2CO3 + H2O
Forming of CO2 from carbonate ion
CO32- +2H+ -----> CO2 + H2O
*The Carbonate ion can also turn into carbonic acid
Sorry if I wasn't clear when writing the reactions, I can't write in sub/super-script on a youtube comment
So your point is: the more carbonate in the water, the more acidic the coffee will be. Is that right?
@@sriwahyanibudianingsih1534
Well it could go ether way. The carbonate can ether turn into carbonic acid or be released as CO2. It all depends on which reaction is more likely to happen. And that has to be figured out through experimentation.
The equilibrium of carbonic acid and aqueous carbon dioxide is heavily favored towards the carbon dioxide side, especially at higher water temperatures, so you should have a high conversion rate to CO2. If a very fresh coffee with a great deal of CO2 in solution, though, this could hamper the conversion and leave a higher carbonate concentration, by comparison, since the stoichiometry is loaded to the CO2 side; this can leave a greater textural difference when comparing coffees with this particular type of hardness.
Interesting as always
@5:01 did you burn your finger? Cut? What happened?! James you can't hide it from us! 😁 I hope whatever it is. It has healed.
Sharp knife + onion + idiocy = blood + pain. Nearly healed though!
I grew up in Australia and now I live in Italy. I remember distinctly there was a program where in America they developed a fast take away coffee service . The device heated up by having an internal explosion mechanism.
Does anybody know about this product if it still exists or if they took it off the market? I know it definitely existed and they gave it a trial run. Any info would be appreciated
Hi, James! I tried to set up your experiment, but with one more cup: mix together hard and soft water. Same amounts like in cup with hard water bloom.
Taste quite similar to cup with hard water bloom.
The hard water should neutralize a bit of the acid in the coffee.
...liberating more gasses as a result of the chemical reaction, thus more bloom.
Ok so maybe in this video I'll learn what a bloom is.
So do you keep the harder water bloom as part of your total brew yield or are you separating it, and just tasting the brewed yield post bloom? My question is, how does a bigger bloom effect TDS/extraction? Is there a direct correlation?
A shop where I worked made cortado-size espresso drink where the shot was floated over cold milk and simple syrup.
The espresso floated in different ways across the many dairy and non dairy milks and milk temperature also played a role. I think it's probably a sort of basic matter of density and maybe fat content but I'd love to see you lay it out in this kind of video
I tested this, James, and each time I scoured my press pot with metal cleaner so it was pristine without any oil residue, used separate clean metal filters + paper filters (I use paper as well as metal as the inclusion of paper cuts down on coffee "silt" and makes the cup more delicate to me), same extraction times, and the same bloom time. Hard water for the initial bloom makes a noticable difference, and as I don't like really acidic coffee, proved good to me. Also, bloom time matters a great deal...started out at 20 seconds...wasn't enough. Increased to 30, as well as stirring later on.
The Hoffman effect is real. Can't believe I'm experimenting with hard water and soft water blooms now while most of my peers wouldn't know the definational difference even becuase neither did I.
A collab between James Hoffmann and Peter McKinnon would be fire🔥🔥🔥
Both of you share the same love for coffee yet you both are so different.
What if we mess with the pH of the water? I'd like to participate in an experiment like that.
Possibly the volume of the bloom is due to the surface tension of the liquid forming the bubbles
Hard water with more dissolved calcium will have a higher surface tension and therefore stronger & bigger bubbles
This is the correct answer. The "volume of the bloom" was never measured, only the size of the foam created by the bloom. Less foam formed because interfacial tension was lower, not because the coffee released any less gas. My hypothesis is that the bloom is exactly the same in terms of how much gas is released from the coffee.
@@matthewbaker7513 so the taste difference will be only the minerals in the water?
All my drinking water is RO water. No wonder my fresh coffee wasn't doming much in my V60
You need a "remineralizing" filter added to the RO system. RO water exposed to air actually becomes acidic which can affect your brewing equipment such as espresso machines.
@@jackfranks7160 go one better and mix the bicarb and magnesium yourself. Make up concentrated batches and dose bottles of the RO using a syringe. With a bit of googling and creativity you can make it pretty easy. That way you can experiment and change parameters like James is doing.
My man, you should really consider doing documentary commentaries...your voice is so soothing!!
Yeah, kinda bit hypnotizing as well
Easy. The lime in hard water neutralise the CO2 that forms carbonic acid. Thats why it blooms harder.
Came here coz of coffee, stayed coz of James's expressions
Love it. Everything: intro video, hypothesis, experiment, conclusions, the grand question "what if?". Thanks!
So harder water leads to more extraction, and softer - to more acidity?
Harder water does extract more, softer water less. The bicarbonate (or buffer) in the water affects acidity quite a lot but this is already too much of a simplification.
@@jameshoffmann, thanks! I understand, that these are complicated chemical reactions, so impossible to explain here. But strictly from consumer point of view acidity is what I miss most in my home brews, so it's hard (pun intended) not to ask about such things. Anyway, great vids both quality and content wise! Thanks for that!
So a quick newbie question, not sure if you will put it to the test. I've seen many brewing methods and the one always use right now is Kasuya's method. Is there a huge difference in every brewing method on the same variables?
Plastic tubes and pots and pans
Bits and pieces and
Magic from the hand
We're making
Weird Coffee Science
This problem has probably been solved, but just in case. (Credentials: MSc in Chem., currently doing a PhD in Chem. Eng.)
What we know: more foam is formed when using harder water and the final coffee is less acidic
Hypothesis: the increased bloom is from the carbon dioxide released by the bicarbonate and not from the coffee.
Bicarbonate can react with protons to form eventually CO2 and water. We know that coffee is acidic and therefore releases protons to the solution. Therefore, the final coffee will be less acidic, as some of the protons will be consumed in the reaction that converts bicarbonate to CO2, that in turn gets released and trapped in the foam.
CO3 (2-) + H(+) HCO3(-) ; HCO3(-) + H (+) H2CO3 H2O + CO2 [the final gaseous product in the bloom]
The current experimental setup can not determine if the coffee itself loses more or less of its trapped CO2, but we can say for sure that when the water contains more bicarbonate more gas gets released, which is inline with the much simpler hypothesis above. Therefore an alternative experimental setup would need to be constructed to determine the CO2 release from the coffee. A scientific approach would be to use IR spectroscopy to determine CO2. But this setup also has its flaws.
Thank you!
LOVE LOVE LOVE this series!!!
Unfortunately the release of CO2 carries with it aromatic compounds which I prefer to retain. Cook your coffee cowboy style in a pressure cooker. When max pressure is attained remove from heat and let cool so all is reabsorbed then refrigerate In pressure vessel. Use just roasted coffee for max pressure with minimal heat.
(Staling is the process of intentionally removing CO2 so metal coffee cans don’t explode. Don’t stale YOUR coffee!)😂
I wonder if the "bigger" bloom is ACTUALLY removing more CO2, or if the hard water just traps more foam? It could be that the same amount of CO2 is released by both, but the harder water has more surface tension and creates more bubbles? I don't know if you'd be able to measure this accurately. I imagine the weight of the released C02 is probably well under 0.1g
salt in hard water isn't consist for flavor ..if your serious about this... Try distilled water hit with a quick boil to release gas in the water, then use the same water in ice in the glass for your pour over, which 1) the empty water is stickier ( vs soap making it wetter) and quickly with less quirky salt interactions ..the ice over method " the kyoto method" also captures the delicate aromatics we smell that taste incredible or horrible depending on the coffee and roasting
Fyi best salt is exothermic ( it's pyramid shaped available as MALTON and 1-3 of these grain/crystal of it activates determjnistically ..the ionic taste detectors on the tongue rely on this..as simple electrolyte..in Mexico we use salt on glasses for comparable reason with beer, margaritas
Next try temp ascending in temp start 120, then 140. This progressive temp doesn't burn the 100 or so of 1000 ish compounds
I don't understand why the coffee from the bloom is not discarded. If the goal is to degas and ultimately improve the brew why isn't the coffee from the bloom discarded?! Am I taking crazy pills?