Thank you all for the kind words about hitting 100,000 subscribers! I know it is just an arbitrary number, but I can't deny that it feels good! You're an amazing community, and I feel lucky to have subscribers and people watching who want to contribute positivity and positively to coffee! Thank you thank you!
I have been experimenting with blended extractions, and would interesting exploration for the coffee science series. Rather then optimize a single extraction, its sampling then mixing different extractions. There are valuable flavour characteristic present in over- and under- extracted coffee that find a place when presented in their appropriate concentration.
Chemist here. Decent explanation of buffers but an important note is that different buffer solutions have different buffering capacity and different useful pHs. Bicarbonate ions have a pretty distinctive taste, so that may mess with the coffee. Other buffers worth trying that are non-toxic (and have different taste profiles) (make sure you have food-safe/high purity stuff before trying this) - trisodium citrate (E331 - used to flavour club soda) or potassium citrate (E332 - used in baking iirc) - disodium citrate (E331ii - same uses as trisodium citrate) - potassium tartrate (E336 - used in baking, so should be possible to find) - monopotassium phosphate (E340 - used in diary products sometimes, so should be possible to find)
@@butsukete1806 sodium carbonate does not act as a buffer on its own. It's just a strong base in water. You can prepare a carbonate bicarbonate buffer (there's tools online on the ratios) by mixing sodium carbonate and bicarbonate. This buffer will buffer between pH 9 and 10, so it is significantly more alkaline that bicarbonate carbonic acid buffer. This should make it more potent as a way to remove acidity but this is a double edged sword
E336 can refer to both potassium tartrate and bitartrate, but I think you were referring to the bitartrate in saying it's used in baking - potassium bitartrate is cream of tartar, and is most well known on FoodTube as that acidic powder that you add to egg whites before whipping to make meringues more stable.
Probably could do a very dilute calcium hydroxide solution, as well (it's safer than other common hydroxides and since it's used in pickling, easy to find food grade). It might react with diluted carbon dioxide within the coffe, what would make the coffee look cloudy and weird, though;
I was thinking, if this is why I prefer americano vs espresso, especially light roasts. Most specialty coffees are lighter roasts which I never liked as espresso.
@@jackfranks7160 maybe try a turbo shot, Lance Hendrick did a good video explaining literally EVERYTHING about it and in my experience turbo shots are great for lighter roasts
Me: Studying (Buffers acids bases) for my final chemistry exam tomorrow... James: Uploads a video on Buffers and acidity in espresso Coincidence? I don‘t think so! Congrats on 100k James!! Love your videos!
At one time in my life I was considering being a Chef, so I studied for a short time with the chef of the Paulist Fathers in San Francisco, the great and unsung Cordon Bleu trained Chef Josephine Araldo. The Fathers raved about her coffee, and I had heard stories from visitors that her was coffee was amazing, and having a cup or two in the mornings myself, nor could I disagree, it had a rich, full flavorful, that was soft, and nonacidic. People often asked the Fathers what the secret was and they would throw up there hands say, "....we do not know, she refuses to tell us, it is her secret...."! I believe they did know, but it was sort of an in joke. I wondered why her coffee was so good, when there was so much bad coffee everywhere. Of course she ground her own beans, but the beans were not a special mix or type, it was a medium roast "house blend" in a large bag that she bought from some where in San Francisco, at time when most people did not use whole bean coffee. She brewed coffee in a large professional restaurant brew style machines ( the Fathers drank a lot of coffee ). While I was setting up for breakfast one morning she called me over and told me to watch her, She used about half as much more coffee than would have been a regular dosage into the brewer, then added two or three broken Egg Shells she had pulled out of a box ( she took shells from the eggs she used previously and then boiled and dried them ), the rind of one quarter an Orange, a quarter teaspoon of Bicarb Of Soda, and a literal pinch of Salt, and then brewed. It created an amazing batch of coffee and I felt honored knowing her secret, though at the time I didn't understand how or why all of that worked.
Wow, I know the egg shell trick is used with tea brewing as well - but as far as I know, it's used to counter bitterness, not acidity. It works in a similar way to brewing in an unglazed (thus porous) ceramic teapot which interacts with the brew to reduce bitterness. Interesting mix though! Salt is also good for counteracting bitterness (at least, perceived bitterness, similar to using sugar to counteract acidity perception as mentioned in the video).
@@daniel.lopresti I suspect that's what the egg shell is for here as well, while the bicarb tackles the acidity. Don't know about the orange zest, though. Maybe for fruitiness?
@@daniel.lopresti Salt is a flavor enhancer. Tiny amounts can improve a lot of things, especially those with subtle flavors. MSG too though it's about 10 times as powerful, so be careful.
"Half as much more coffee" is quite a confusing phrasing. I'm intrigued with this method but don't know whether you mean "0.5" or "1.5" times as much coffee. I'm guessing (as well as my wife) that it's probably "1.5" times the amount but if you could clear this up I'd definitely give it a try.
I just tried a variation of this and have been adding a pinch(very small about the size of pepper corn) of sodium bicarbonate distributed over the top of the puck, and it makes a pretty remarkable difference. Definitely removes a noticeable amount of acidity but also dramatically increases the extraction time. Like by at least 25%.
Exactly! Sugar is sweet, because it is alkaline. Another candidate for reducing acidity in coffee (from the chemistry POV) would be soap (soap - technically - is a salt - a compound of a very weak acid and a very strong caustic - when dissolved in water the strength of the alkaline/caustic part prevails - making soapy water taste sweet
This is a bad idea because my friends are already looking at me askance when I'm weighing out my beans and beverages (and thank god my colleagues never see me mixing the week's coffee water)... Imagine their looks when I start dribbling chemicals in their drinks. (Edit: Which is to mean of course that I'm definitely going to do it.)
SpookyFM, my wife got me drinking coffee a couple years ago when I was not a fan of coffee at all. She loves strong coffee and her favorite right now is a dark roast. Now that I have found this channel, I’m weighing my beans and water each morning. She looks at me like I’m nuts. I just can’t start adding things to my water, let alone my coffee after I’ve brewed it. Lol.
Here in HongKong, “Cha Chaan Tang” mixes egg shells with the coffee grounds. I believe the calcium carbonate acts as a neutraliser as you suggested. Thanks very much for your informative video!
I found this most interesting. I lived in Munich for several years where the water is extremely hard, so we were always descaling our espresso machine. The local brewers chose to counter the water hardness by using more darkly roasted barley (or wheat for weissbier). Many years ago, living in a city with fairly moderate pH water, I used to enjoy the Sumatran/Javanese coffees, but now I am in another hard water area, they no longer appeal. It is a complicated topic.
Brilliant, Mr Hoff! I bake cakes for a living and although I'm no scientist, found the little I know, of great use in vegan baking. Chemistry, as I often say. This fine vid, made me think of adding salt to a tomato, for sweetness. Counter-intuitive, but it works. The salt stimulates your salivary glands, causing them to produce the saliva that distributes flavour to the old taste buds. It also suppresses the perception of bitterness, making the tomato taste even sweeter. Made me also think of whisky science. Adding miniscule amounts of water to a fine malt. I read somewhere that the taste improvement happens/changes, because alcohol molecules and those that determine whisky flavour, tend to stick together. Could be tosh, but it does make your coffee experiment ever more relevant.
Great video, Mr. Hoffman. Some cheap pH paper off Amazon would give you a way to relate a number value to the level of acidity you are sensing in the coffee. It would be interesting to see how much the pH is actually changing with brewing with alkaline water vs adding alkaline water.
I love this series! I'm a huge fan of both science (am a biologist) and coffee. The interface between coffee and science is so exciting! Makes me want to participate in the field. Thanks, James!
Tried this a while back, and it's super interesting. A neat side effect is that lower bicarb water has lower viscosity, so if you use this trick to lower the bicarb of your brew water, you can grind a little finer too. Another neat little effect is that if you add a lot of it at once the espresso actually foams up like new crema is appearing out of nowhere. Not the most practical magic trick, though, since enough bicarb to do that tends to ruin the shot.
Thank you for confirming I am not weird lol. I already put a pinch of either baking soda or salt in my coffee and everytime I am with company, they always question me about it lol. I was only doing as a "flavor enhancer" without thinking about the science behind it but it makes sense. 👍
The free espresso at my workplace is the most acidic I have ever tasted, to the point where it curdles my non-dairy lattes. I found that it doesn't take much sodium bicarbonate to fix the coffee, just the smallest pinch, and with that amount you don't really taste the sodium bicarbonate. It completely neutralizes the tart taste of the coffee as well and makes it really smooth when I drink it as an americano. I have kept a mason jar of the white powder with me at the workplace since this discovery. People really should just try it. It really doesn't need to be an exact science of the trying to create a buffer recipe with final molar concentrations, monitoring the pH... just add a small pinch, then if it's not enough add more. If it's too much then add somewhere in the middle. People seem to be too scared to actually just try it out but the worst that would happen is you just made a bad cup of coffee even worse.
The is a super cool experiment and encouraged me to do some testing of my own. I have a delicious, very floral light roasted coffee that I usually drink as V60 pourover. In the past I tried making espresso with it in my Flair, but the result was always very acidic. The wonderful floral notes came through, but were somewhat drowned out by the acidity. After watching your video I mixed up 200g water to 1.3g baking soda per your instructions, and added 2g of that directly to the brew chamber on my Flair before filling it with the brew water. I loaded my Flair with 15g of coffee and pulled a 30g shot. It was wonderful! The acidity in my shot was reduced (though not gone) and the floral notes of the coffee shone through in a bright and tasty espresso. Thank you for the wonderful tip!
I've commented this here before, but OH MY GOODNESS I love your cinematography, on top of positively adoring your content. Thank you for being a truly sterling part of this world, James. What you do is beautiful, and as Plato put it, "The Good is Beautiful."
James, this is such an intriguing experiment, and one which i’ll definitely be partaking in. Making a dropper bottle of high alkaline water at this very moment (as i’m drinking some Vichy Catalan, appropriately) to test it out at home and various coffee shops to see how it affects flavour of different origin coffees, on ristretto & espresso. Also a huge congrats on the 100k, and thank you for all the great content, for your honest in depth & sincere reviews, and pushing the world of coffee to new heights.
Isn't this why there's a historical practice of adding egg-shells alkalinity to some brews? BTW As a roaster in South East Asia and a coffee history nerd, I'm really loving your channel's coverage of relevant topics. Keep up the great work
I had been contemplating adding bicarbonate recently because of a highly acidic cup of espresso I had. The good thing about bicarbonate is that it will turn into a sodium salt with components that are in the coffee and if you use the right amount you will not be tasting bicarbonate at all but the reduced amount of acid and a very dilute organic sodium salt solution. With your simple test and facial reaction I feel more validated to try to use bicarbonate in certain instances. The acids present in coffee are what give it some of its complex flavor profile, but it is clear that some types will for whatever reason be too acidic. Thanks for your honest, elegant and informative videos!
What I liked most about this video is the premise; that certain coffees are simply going to be very acidic as espresso, even when "properly" extracted. I always tell people who are struggling with tart espresso to dilute it down to brew strength. If it tastes great, then you aren't likely suffering from under-extraction so much as you are experiencing the full force of that coffee's natural acidity. This is a subjective thing, and everyone's tolerance/perception will be different but - like you mentioned - those shots are probably still complex, sweet, and aromatic, it's just difficult to get past the palate-wrecking nature of acidity. This is why I think it's silly to put espresso in a box, where it has to be "this one way/thing", because you are just robbing the potential for greater enjoyment of a given coffee by forcing it into a predetermined mold.
Oh my, I am TOTALLY going to give this a good try. I have been dialling in an old Gaggia Baby 91 that's cost me just $20 and a bottle of descale liquid. It, like most Italian machines, has 0 chill and the pump gets some awesome but acidic shots when I get a great tamp down. Still getting as much practice in as possible, but the beans I have have such a spicy, back of throat kick with the acidity with a bright fruity cherry note that it's a bit hard to drink without some Coffee Mate. (Terrible, I know!) I will definitely give this a try. I'm a lover of kitchen science/chemistry, especially food chemistry. I look forward to seeing what I can get out of these beans.
Hi James! thank you for this video in particular. At my cafe we only brew single origin coffees (for both filter and espresso) and have a particular bend toward washed Ethiopian coffees. We have played around in the past with seasoning espressos after brewing with just a few drops of a 20% saline solution (á la Dave Arnold) with enjoyable results. We've also added small amounts of a solution of isomalt to intensify mouthfeel, we've also played with isomalt in our iced coffee (a modified version of Windelboe's sugar in the iced coffee) but ultimately these techniques have never seen day to day service because of what amounts in my head to a fundamental lack of understand of my role. I'm not sure if my job is to showcase coffees, I.E. source, brew, and serve them as best I can or if it's to make the tastiest drinks I can. is modifying a coffee post-brew somehow disingenuous? is it faking? or is it our duty to make the tastiest coffees by any means available? I'd love to know your thoughts.
4:30 minutes into the video. James: Let's use a filter-roasted Kenyan as base for this experiment. Me: Oh boy, I can't wait for his expression when he tastes it :-)
Somehow, I thought I've seen this topic somewhere before, and I went back to check it and found that, indeed, Jonathan from Coffee Ad Astra posted in one of his blogs saying that he once messed up with the brewing water but found it amendable by adding bicarb afterwards. So, rather than playing a role directly in coffee extraction, bicarb may have more to do with the taste of it. And today, we have our Mr.Hoffmann, the business owner, the coffee professional, the yesterday champion, the necromancer, the fine UA-camr loved by his patreons and sponsored by fine companies, look into the topic! Chemistry is lovely, we should talk about it more Lol.
Love these kind of vidoes, ever since I watched your video about removing crema from americanos i've been mostly hacking my blacks that way. It's great that you put your ideas into motion and record experiments like this, big fan!
I have seen in many coffee shops where they serve a glass of sparkling water, (it could be soda water, which is basic whereas sparkling is acidic) with my espresso. Your video made me wonder if this maybe an establish thing or they are doing it for some other reason. For me I treated the sparkling(or soda water) like a chaser that I drink after the espresso which mellows the harshness in the throat. Anyway I don’t reckon it’s weird at all, some espresso are quite concentrated, and I would do anything to mellow down a sour espresso. It’s like adding water to whisky.
Well, just went and added some sodium bicarbonate directly into my portafilter of a double espresso of my decaf coffee. I use the Swiss Water version of the decaf, and I found it very sour. No amount of fiddling with grind and ratios would seem to make any difference. But this does the trick. Will still have to experiment, and I know that adding it into portafilter makes for the most inconsistent method, but it works, and that is the most important thing. Thank you James, oh so much, for teaching me how to make and enjoy coffee
in my house where we are all dairy free, most single origin beans we get split when mixed with soy milk, and adding a bit of bicarb can sometimes fix that, i think this is the same effect, but explained a lot better. but we always put too much in and can taste the bicarb, need to do the dropper thing. great video
Recently I've been making moka pot "espresso" using beans that are intended for filter coffee. The result is an intense, fruity drink, that is honestly a little too sour to enjoy fully. Some of that sourness can be balanced by allowing the moka to brew more of the bitter notes at the end. But the best results come when turning that fruity, sour, concentrated shot into a milk drink. The heated milk provides the sugar, which (as you said) serves to harmonise the acidity. The result is a cappuccino-style drink that everyone I've served it to has commented on being one of the best coffees they've ever had. And I'm a coffee newbie (hooray for lockdown!). I think this opens up a whole other door for coffee lovers. Not everyone loves dark roasts, but they're what's predominantly used in espresso and, therefore, espresso-based drinks. But by changing your approach, and embracing the factors that compliment sourness, you can make drinks that massively outperform the traditional recipes for those people whose tastes lean towards light-roasts. Experiment, dear coffee lovers!
Just got myself some fab Kenyan yesterday and as expected it’s incredibly sour when I pull a shot so definitely going to try this over adding sugar. Thanks James.
Does the high-buffer water create any precipitates in the espresso? What about the sodium, what’s happening to it and are you getting any salty flavors?
I did not taste salty flavours but added the bicarbonate directly to the grounds. It really changed an acid roast to a sweet, chocolatey well bodied espresso. I was amazed.
This is so cool. I watched this video a while back, when getting into coffee, but I forgot most of this info. Today I brewed an AeroPress and an espresso with Evian water, which is a very hard water. The espresso tasted amazing, the sourness of the light roast was toned down to allow me to enjoy the flavor a lot more. The AeroPress, however, was a little bit bland. I like it better with soft water. Can't wait to try this experiment with a V60.
Super cool video! In a field like coffee where things often feel very regimented and prescribed, I love that you're showing that there can be a lot of room for curiosity and experimentation too. One question, as an owner/maintainer of the espresso machine you used: Did you flush the boiler when you changed the water? The brew boiler isn't large, but it holds a few shots worth of water and I could see it affecting the actual water makeup if some care isn't taken
I did that, and I was quite surprised. Texture does change a little bit, but the change in my opinion is pleasant. I have to try making a long black now, that might be interesting ...
I used to add baking soda to a certain coffee drink I used to make. I did it specifically to neutralize the acidity in both the coffee as well as the cocoa powder. It worked pretty well.
I traveled through quite a bit of Italy in the late 80s and noticed in the coffee shops many people who ordered espressos put a pinch of a white crystal into their drinks. I picked up the container they were dispensing from and put a bit in my hand, low and behold it was salt. I'll be trying the bicarbonate tomorrow, sounds intriguing.
@@rene3076 Solid - phase extraction (SPE) would be more accurate to describe espresso. It is chromatography in the simplest sense, a liquid extraction that passes through a solid matrix that can separate the solutes based on polarity. Solid-liquid extraction is more general, defined by the simple mixing of solid and a liquid solvent followed by separation of the liquid. Since there is no solute separation happening in the liquid phase, it is not a form of chromatography, and solute separation is dependent solely on misicibility in the solvent. This is more descriptive of a infusion brew. Liquid-liquid and Solid-liquid extraction are quantitative techniques for the concentration of solutes, think soxhlet extractor. They are preparative methods used before the separation techniques like chromatography. A good cup of coffee requires the precise separation of soluble components, i can only imagine how terrible coffee from a soxhlet would be, although strong!
You are on the right track. Bicarbonate of soda helps release carbon dioxide at about 80 degrees celcius. I have added it to my expresso to the middle of the grind before tamping. As it brews thru the grind it produces a less acidic taste. Thanks for doing this video.
Hoffman, Brilliant. Canadian here. Might not be relevant to this specific video but about two weeks ago I commented on one of Hoffman’s videos, having just discovered him. I said in that comment that I feel like I could taste a hundred coffees and notice no difference. Goodness was I wrong. I did not spend a single dime, Just listened to what Hoffman had to say. And wow, my coffee experience has changed. I’m still uncomfortable saying that phrase. But those simple alterations really made major changes in how much I need to add to my coffee before it’s palatable. It doesn’t need any improvement anymore, no sugar or flavouring. Hoffman you’re a magician (Scientist, Professor, mentor) But magician
James Hoffman liked my comment😊 lovely. Also wow I sound like a fanboy. Idk I didn’t think an improvement in coffee skills would really improve my situation this much. Of course this channel teaches a lot deeper than hot beverages.
The point of buffer solutions is to *maintain* a certain pH range, keeping your solutions pH from changing to unfavorable levels. This is technically just adding a basic solution to raise the pH.
Apologies if i am asking something all to apparent but what about salt. You’ll still bring the PH up it’s obviously readily available and in small amounts in may actually bring out the origin of the coffee the same as it does for flavors when cooking.
Random thought: so salt (like ordinary table salt) changes your perception of coffee by reducing bitterness. Specifically, the sodium ion actually changes how the butter taste receptors react in your mouth, inhibiting them. When you've mixed in the sodium bicarbonate, you're releasing sodium ions into the drink (I think. My stoichiometry might be off, it's been a while). This can affect how you actually taste the coffee and might be the other "changes" you taste in the espresso. Thoughts? Also, salt in coffee could be something to explore. I know a small pinch in the grounds has made some very cheap coffees somewhat more bearable for me.
Bicarbonate is actually forming salts with the acids, mainly sodium citrate, malate and quinate. Those vary in taste from "salty" (malate) to slightly sour (citrate) and somewhat bitter (quinate).
Sodium ions don’t generally produce scale. In fact commonly in industrial uses we use resin filters that replace calcium ions with sodium to prevent scale buildup in boilers and other equipment where heated water is needed.
Congrats on earning a Silver Play Button!! I'm very curious to see how I like a more buffered shot, because high acidity is my favorite attribute of espresso. I'll drop another comment once I try it out.
Hello Mr. Hoffmann. A pleasure. Now adding sodium bicarbonate is about the best agent of alkalinity possible. No better choice to make so far. I can add this to your info: By adding bicarbonate to your coffee after extraction you do not change the extraction process itself but you cause more of the acids already present in the cup of espresso to stay in your body beacause they are already bound and neutralized and thus not perceived as acid anymore. So everything you explained is actually right, but adding bicarbonate can better the taste of acidic coffee at the expense of more acid accumulation in your body on long term conpared to not using bicarbonate.
What would happen if you inoculated the coffee grounds directly with a dose of sodium bicarbonate (bicarbonate of soda/baking soda), so that it gets extracted with the coffee in the portafilter?
That would be pretty tough without a really nice scale. He is using 0.13 grams of sodium bicarbonate per double espresso. It would be interesting to be able to do it to help keep your machine scale free, though. pH can definitely change the solubility of certain compounds as well as obviously directly affecting flavor perception. i have a feeling that the two espressos he made with altered water chemistry may be significantly different because of the altered extraction chemistry in the first vs. just neutralizing some of the acidity in the second coffee. Water chemistry and pH is always monitored in beer brewing as a way to control the extraction of tannins that lead to astringency (as well as other reasons), so I suspect pH control during coffee extraction could be equally important.
The AWS LB-501 scale is a really nice scale that measures down to 0.01g and up to 500g - Plus it's not all that expensive, though harder to come by in Europe.
i have been adding heart salt (higher potassium chloride).....just a small amount as I use filtered rain water and that would have next to zero minerals....now i will try it with baking soda and see the difference...adding salt gives my coffee more body!
So I saw that you were using a Sage/Breville machine for your tests. Breville states that they do not recommend water from reverse osmosis filtration for use in their espresso machines because it lacks the necessary mineral content needed for their sensors to operate. So I'm adding a splash of tap water to my tank each time I fill it up with water form my large filtration system. All that to say, I have no idea what my water chemistry actually is and I was one of those who wanted this video to be THAT video about water chemistry. :D Congratulations, James, on the 100K milestone. You're seriously knocking it out of the park content wise!
The reason they suggest not using reverse osmosis filtered water is because it's really corrosive and doesn't make good tasting coffee. Use the 'water hardness' strip provided with the machine, then go into settings and set 'water hardness' accordingly. It'll determine the cleaning cycle and internal filter change intervals.
@@space.youtube actuality they state quite clearly that it's about their sensors and taste. www.brevilleusasupport.com/bes900xl/troubleshooting/ see the section about the importance of water. As for the corrosiveness of the water, I'll have to look into that. They do not provide a test strip with the model I have here in the US.
At the shop I work at, we make a form of iced americano using Topo Chico Mineral water, and it makes the espresso wildly calmer tasting. I want to try adding a bit of flat mineral water to an espresso and tasting it to see if it tames the acidity.
I mentioned adding SB(baking soda) to your coffee in a previous video's comment section. It has been done here by many for decades. Adding just a pinch to a pot of coffee really can round out the flavors.
Potassium Bicarb is a good substitute for Sodium Bicarb if you are on a low sodium diet. Some "experts" also use epsom salt and calcium chloride in coffee water. I am not interested in manufacturing espresso water but I may try some KHCO3 in the cup.
This video is great, do one where you really talk about the influence of the minerals on taste! I'm sure there are more people interested in a bit of extra chemistry
haven't people been mixing bi-carb with grinds since drip machines were around? you can also mix directly in espresso grinds and along with it's buffering characteristics, it will also produce more crema. adding a pinch of baking soda to the grinds feels like a cheat to not just buffer the acidity but the grocery store coffee and blade grinder too, but the way you put it feels more sophisticated.
Love this test. Could you possibly do a video about the concept of freezing and/or refrigerating beans? Whether or not it preserves flavour and extend expiration. Maybe some blind tests?
This is absurd. Coffee snobs will have you roast a Kenyan barely to the finish of first crack to preserve it's "character", and even though it tastes like battery acid you're supposed to pretend to like it if you want to be in the coffee club. Bicarbonate of soda tastes AWFUL. Try some just dissolved in water by itself. We're supposed to improve that precious Kenyan that we worked so hard to make as acidic as possible by adding an awful tasting base to it? I've got a tip - try a Guatemala Huehuetenango roasted halfway to second crack. It's called balance.
A lot of things can be done to make the coffe taste better or different. Adding strawberrys is one. Adding sugar, honey or milk is one. Adding bicarbonate is one. It's not revolution but it is interesting. I had another idea. If you could pull a shot along a cut-open cable with just small compartments - you could rebuild your espresso again by mixing it all up - or by mixing it up with different proportions... What would make it a little bit like an audio equalizer - but to the espresso.
Love this! As I've been exploring espresso more, I find that ones that I get from most cafes are extremely sour... I might have to sneak some of this along with me.
This is so true. Every other espresso I get at a coffee shop is sour. Do they just not know what they are doing??? I read that sourness is typically caused by low water temp and/or too fast of an extraction. It’s very common though. I thought it was just poor quality beans until I looked into it more
I often drink a splash of sparkling mineral water before a shot of light roast espresso. I have found drinking the mineral water before the shot mellows the initial acidity and the lingering bitterness of the espresso, I presume this must be why. Another benefit is that it cools the mouth, which can make drinking a fresh shot a little more pleasant to the tongue.
Wow, this hack is amazing. I've just got an old Pavoni and keep getting super sour coffee. I don't have a grinder, so probably getting a not perfect grind and underroasted coffee (supermarket stuff unfortunately). Reducing the acidity with this makes a huge difference
Just rediscovering an old Pavoni Professional these last few days which my parents were given years ago - it was gathering dust, but I remember having used it years ago and it made pretty weak sour shots (and I didn't have a clue about coffee back then). I'd say it's most likely the supermarket pre-ground coffee as you say, which is not quite fine enough - but more likely over- than under-roasted, especially if the texture/thickness is good but it's just too acidic.
Thanks James for this fantastic input. I was wondering, can we simply add the soda powder like sugar in order to get to the same point? we wouldn't have the "added-water-bias" then.. I'll defently try this in some way at work
I think you'd have to have a very accurate scale to accomplish this, as the prescribed dose and strength (4g of water at 3.2g/liter) works out to just 12.8mg of sodium bicarbonate. As most brewing scales only have a sensitivity of about 100mg (0.1g), it would be difficult to get an accurate and repeatable amount.
I did it an the result was spectacular. Less acidic, sweeter and full body with a rich crema espresso. Just don't overdose it since you still want to keep some slight acidity.
Kava "Acid Neutralized" Instant coffee has potassium hydroxide in it (suggested buffer below). I wonder how much KOH would deliver the same acidity as your 3.2g bicarb to water without the bicarb taste.
Admittedly I don't make espresso at home since I'm broke and its been a long time since I've taken chemistry, but if the whole idea is to add alkaline water to neutralize an espresso's overwhelming acidity, if the amount of buffering solution you would need to add to round out the sourness is so much so as to significantly dilute the espresso, why bother with just a buffering solution? By adding a strong base such as sodium hydroxide or calcium hydroxide to the espresso, perhaps through titration or a dropper, couldn't you get the same effect of rounding out the sourness without as much dilution? Also, on the off chance that James Hoffmann reads this comment, James, could I suggest a weird coffee science video exploring what effect if any variable RPM on an espresso grinder has on the taste, texture, and overall quality of the final espresso cup?
My first thought was to use a little bit of NaOH - lye - in solution rather than bicarbonate. That should be completely taste neutral, at worst adding just hint of salt. Of course, that won't mean the effect ends up being taste neutral. In Norway it's easy to get food safe lye as it's used in preparing some traditional foods.
A super easy way of measuring small amounts of concentrate is by using little 10ml syringes with the millilitre markings up the side. It's how I mix up my jugs of water that I use for brewing and in the machine.
Thank you all for the kind words about hitting 100,000 subscribers! I know it is just an arbitrary number, but I can't deny that it feels good! You're an amazing community, and I feel lucky to have subscribers and people watching who want to contribute positivity and positively to coffee! Thank you thank you!
James Hoffmann congratulation on the 100k ! Cheers for the next 500k !
I have been experimenting with blended extractions, and would interesting exploration for the coffee science series. Rather then optimize a single extraction, its sampling then mixing different extractions. There are valuable flavour characteristic present in over- and under- extracted coffee that find a place when presented in their appropriate concentration.
Works for acid reflux as well ;)
Love your stuff James, you're the big reasons I've gotten into high quality coffee and just wanted to say my taste buds(but not my wallet) thank you.
You help me being explorative as a barista. I learned so much from you! Thanks, James.
Chemist here.
Decent explanation of buffers but an important note is that different buffer solutions have different buffering capacity and different useful pHs.
Bicarbonate ions have a pretty distinctive taste, so that may mess with the coffee. Other buffers worth trying that are non-toxic (and have different taste profiles) (make sure you have food-safe/high purity stuff before trying this)
- trisodium citrate (E331 - used to flavour club soda) or potassium citrate (E332 - used in baking iirc)
- disodium citrate (E331ii - same uses as trisodium citrate)
- potassium tartrate (E336 - used in baking, so should be possible to find)
- monopotassium phosphate (E340 - used in diary products sometimes, so should be possible to find)
What about sodium carbonate? It's easy to make, just bake your baking soda.
@@butsukete1806 sodium carbonate does not act as a buffer on its own. It's just a strong base in water. You can prepare a carbonate bicarbonate buffer (there's tools online on the ratios) by mixing sodium carbonate and bicarbonate. This buffer will buffer between pH 9 and 10, so it is significantly more alkaline that bicarbonate carbonic acid buffer. This should make it more potent as a way to remove acidity but this is a double edged sword
E336 can refer to both potassium tartrate and bitartrate, but I think you were referring to the bitartrate in saying it's used in baking - potassium bitartrate is cream of tartar, and is most well known on FoodTube as that acidic powder that you add to egg whites before whipping to make meringues more stable.
It might be worthwhile to monitor the pH.
Probably could do a very dilute calcium hydroxide solution, as well (it's safer than other common hydroxides and since it's used in pickling, easy to find food grade). It might react with diluted carbon dioxide within the coffe, what would make the coffee look cloudy and weird, though;
Americano Fans: "i told you guys, add water"
I was thinking, if this is why I prefer americano vs espresso, especially light roasts. Most specialty coffees are lighter roasts which I never liked as espresso.
hahaha.... good one!
Ah-ha!!
@@jackfranks7160 maybe try a turbo shot, Lance Hendrick did a good video explaining literally EVERYTHING about it and in my experience turbo shots are great for lighter roasts
Me: Studying (Buffers acids bases) for my final chemistry exam tomorrow...
James: Uploads a video on Buffers and acidity in espresso
Coincidence? I don‘t think so!
Congrats on 100k James!! Love your videos!
Robert Stark you’ve got a final exam in October? Dude I just took my midterm in Biochem 😂 8-week course?
every branch of science can learn from espresso
At one time in my life I was considering being a Chef, so I studied for a short time with the chef of the Paulist Fathers in San Francisco, the great and unsung Cordon Bleu trained Chef Josephine Araldo. The Fathers raved about her coffee, and I had heard stories from visitors that her was coffee was amazing, and having a cup or two in the mornings myself, nor could I disagree, it had a rich, full flavorful, that was soft, and nonacidic. People often asked the Fathers what the secret was and they would throw up there hands say, "....we do not know, she refuses to tell us, it is her secret...."! I believe they did know, but it was sort of an in joke.
I wondered why her coffee was so good, when there was so much bad coffee everywhere. Of course she ground her own beans, but the beans were not a special mix or type, it was a medium roast "house blend" in a large bag that she bought from some where in San Francisco, at time when most people did not use whole bean coffee. She brewed coffee in a large professional restaurant brew style machines ( the Fathers drank a lot of coffee ). While I was setting up for breakfast one morning she called me over and told me to watch her,
She used about half as much more coffee than would have been a regular dosage into the brewer, then added two or three broken Egg Shells she had pulled out of a box ( she took shells from the eggs she used previously and then boiled and dried them ), the rind of one quarter an Orange, a quarter teaspoon of Bicarb Of Soda, and a literal pinch of Salt, and then brewed. It created an amazing batch of coffee and I felt honored knowing her secret, though at the time I didn't understand how or why all of that worked.
Wow, I know the egg shell trick is used with tea brewing as well - but as far as I know, it's used to counter bitterness, not acidity. It works in a similar way to brewing in an unglazed (thus porous) ceramic teapot which interacts with the brew to reduce bitterness.
Interesting mix though! Salt is also good for counteracting bitterness (at least, perceived bitterness, similar to using sugar to counteract acidity perception as mentioned in the video).
@@daniel.lopresti I suspect that's what the egg shell is for here as well, while the bicarb tackles the acidity. Don't know about the orange zest, though. Maybe for fruitiness?
I’ve got to try this
@@daniel.lopresti Salt is a flavor enhancer. Tiny amounts can improve a lot of things, especially those with subtle flavors. MSG too though it's about 10 times as powerful, so be careful.
"Half as much more coffee" is quite a confusing phrasing. I'm intrigued with this method but don't know whether you mean "0.5" or "1.5" times as much coffee. I'm guessing (as well as my wife) that it's probably "1.5" times the amount but if you could clear this up I'd definitely give it a try.
I just tried a variation of this and have been adding a pinch(very small about the size of pepper corn) of sodium bicarbonate distributed over the top of the puck, and it makes a pretty remarkable difference. Definitely removes a noticeable amount of acidity but also dramatically increases the extraction time. Like by at least 25%.
What a year to be alive in 2019! Watching James Hoffmann drinking espresso.
Wait for 2020 man, its really something.
2021 loading...
There’s a company called third wave water that sells mineral supplements for a gallon of distilled water. I saw it on Shark Tank,TV,
@@christiansmith1663 No it was not
we need to go back
- Espresso! - Sugar? - Bicarbonate of soda, please!
Exactly! Sugar is sweet, because it is alkaline.
Another candidate for reducing acidity in coffee (from the chemistry POV) would be soap (soap - technically - is a salt - a compound of a very weak acid and a very strong caustic - when dissolved in water the strength of the alkaline/caustic part prevails - making soapy water taste sweet
@@onemanmob6756 weird coffee science must be updated :D @jimseven
"Would you like cream with that?" "Yes, cream of tartar!"
This is a bad idea because my friends are already looking at me askance when I'm weighing out my beans and beverages (and thank god my colleagues never see me mixing the week's coffee water)... Imagine their looks when I start dribbling chemicals in their drinks.
(Edit: Which is to mean of course that I'm definitely going to do it.)
tell them you brew your coffee beans with dihydrogen monoxide (make sure you don't switch it with hydrogen peroxyde)
Sounds like your friends just dont like coffee
SpookyFM, my wife got me drinking coffee a couple years ago when I was not a fan of coffee at all. She loves strong coffee and her favorite right now is a dark roast. Now that I have found this channel, I’m weighing my beans and water each morning. She looks at me like I’m nuts. I just can’t start adding things to my water, let alone my coffee after I’ve brewed it. Lol.
SpookyFM - lol, that’s so funny. I totally understand! Best regards
@@insomniafuel000 Haha, that's a great idea! I'm going to put a "dihydrogen monoxide" label on our water filter or something.
Here in HongKong, “Cha Chaan Tang” mixes egg shells with the coffee grounds. I believe the calcium carbonate acts as a neutraliser as you suggested. Thanks very much for your informative video!
Interesting to know！
My first thought was to add a bit of chalk dust to the grounds, which would do more or less the same thing.
Makes for a perfect feritilizer for your garden too!
Oh interesting -- I've heard this as a practice in midwestern churches as well!
@@charleslambert3368 try ash instead! Would probably affect the texture and flavor less
I found this most interesting. I lived in Munich for several years where the water is extremely hard, so we were always descaling our espresso machine. The local brewers chose to counter the water hardness by using more darkly roasted barley (or wheat for weissbier). Many years ago, living in a city with fairly moderate pH water, I used to enjoy the Sumatran/Javanese coffees, but now I am in another hard water area, they no longer appeal. It is a complicated topic.
Brilliant, Mr Hoff!
I bake cakes for a living and although I'm no scientist, found the little I know, of great use in vegan baking. Chemistry, as I often say.
This fine vid, made me think of adding salt to a tomato, for sweetness. Counter-intuitive, but it works. The salt stimulates your salivary glands, causing them to produce the saliva that distributes flavour to the old taste buds. It also suppresses the perception of bitterness, making the tomato taste even sweeter.
Made me also think of whisky science. Adding miniscule amounts of water to a fine malt. I read somewhere that the taste improvement happens/changes, because alcohol molecules and those that determine whisky flavour, tend to stick together. Could be tosh, but it does make your coffee experiment ever more relevant.
I really love the intro to this series, absolutely 10/10
Great video, Mr. Hoffman. Some cheap pH paper off Amazon would give you a way to relate a number value to the level of acidity you are sensing in the coffee. It would be interesting to see how much the pH is actually changing with brewing with alkaline water vs adding alkaline water.
What’s the pH I should try to get?
I love this awesome Weird Coffee Science series! It's so hard to find similar things like this around, keep up the good work James :D
I love this series!
I'm a huge fan of both science (am a biologist) and coffee. The interface between coffee and science is so exciting! Makes me want to participate in the field.
Thanks, James!
This is honestly your best video out there. Even though everyone of them are super informative, this one tops it. I see this being used, definitely!
Tried this a while back, and it's super interesting. A neat side effect is that lower bicarb water has lower viscosity, so if you use this trick to lower the bicarb of your brew water, you can grind a little finer too.
Another neat little effect is that if you add a lot of it at once the espresso actually foams up like new crema is appearing out of nowhere. Not the most practical magic trick, though, since enough bicarb to do that tends to ruin the shot.
Thank you for confirming I am not weird lol. I already put a pinch of either baking soda or salt in my coffee and everytime I am with company, they always question me about it lol. I was only doing as a "flavor enhancer" without thinking about the science behind it but it makes sense. 👍
The free espresso at my workplace is the most acidic I have ever tasted, to the point where it curdles my non-dairy lattes. I found that it doesn't take much sodium bicarbonate to fix the coffee, just the smallest pinch, and with that amount you don't really taste the sodium bicarbonate. It completely neutralizes the tart taste of the coffee as well and makes it really smooth when I drink it as an americano. I have kept a mason jar of the white powder with me at the workplace since this discovery. People really should just try it. It really doesn't need to be an exact science of the trying to create a buffer recipe with final molar concentrations, monitoring the pH... just add a small pinch, then if it's not enough add more. If it's too much then add somewhere in the middle. People seem to be too scared to actually just try it out but the worst that would happen is you just made a bad cup of coffee even worse.
The is a super cool experiment and encouraged me to do some testing of my own.
I have a delicious, very floral light roasted coffee that I usually drink as V60 pourover. In the past I tried making espresso with it in my Flair, but the result was always very acidic. The wonderful floral notes came through, but were somewhat drowned out by the acidity. After watching your video I mixed up 200g water to 1.3g baking soda per your instructions, and added 2g of that directly to the brew chamber on my Flair before filling it with the brew water. I loaded my Flair with 15g of coffee and pulled a 30g shot. It was wonderful! The acidity in my shot was reduced (though not gone) and the floral notes of the coffee shone through in a bright and tasty espresso.
Thank you for the wonderful tip!
I've commented this here before, but OH MY GOODNESS I love your cinematography, on top of positively adoring your content. Thank you for being a truly sterling part of this world, James. What you do is beautiful, and as Plato put it, "The Good is Beautiful."
100k subs congrats james !
James, this is such an intriguing experiment, and one which i’ll definitely be partaking in. Making a dropper bottle of high alkaline water at this very moment (as i’m drinking some Vichy Catalan, appropriately) to test it out at home and various coffee shops to see how it affects flavour of different origin coffees, on ristretto & espresso. Also a huge congrats on the 100k, and thank you for all the great content, for your honest in depth & sincere reviews, and pushing the world of coffee to new heights.
6:49 it doesn't hurt my face... WHAHAHA classic hoffmann! gotta love the hoff! make a tshirt with this quote!
Isn't this why there's a historical practice of adding egg-shells alkalinity to some brews? BTW As a roaster in South East Asia and a coffee history nerd, I'm really loving your channel's coverage of relevant topics. Keep up the great work
I had been contemplating adding bicarbonate recently because of a highly acidic cup of espresso I had. The good thing about bicarbonate is that it will turn into a sodium salt with components that are in the coffee and if you use the right amount you will not be tasting bicarbonate at all but the reduced amount of acid and a very dilute organic sodium salt solution. With your simple test and facial reaction I feel more validated to try to use bicarbonate in certain instances. The acids present in coffee are what give it some of its complex flavor profile, but it is clear that some types will for whatever reason be too acidic. Thanks for your honest, elegant and informative videos!
What I liked most about this video is the premise; that certain coffees are simply going to be very acidic as espresso, even when "properly" extracted. I always tell people who are struggling with tart espresso to dilute it down to brew strength. If it tastes great, then you aren't likely suffering from under-extraction so much as you are experiencing the full force of that coffee's natural acidity. This is a subjective thing, and everyone's tolerance/perception will be different but - like you mentioned - those shots are probably still complex, sweet, and aromatic, it's just difficult to get past the palate-wrecking nature of acidity. This is why I think it's silly to put espresso in a box, where it has to be "this one way/thing", because you are just robbing the potential for greater enjoyment of a given coffee by forcing it into a predetermined mold.
Oh my, I am TOTALLY going to give this a good try. I have been dialling in an old Gaggia Baby 91 that's cost me just $20 and a bottle of descale liquid. It, like most Italian machines, has 0 chill and the pump gets some awesome but acidic shots when I get a great tamp down. Still getting as much practice in as possible, but the beans I have have such a spicy, back of throat kick with the acidity with a bright fruity cherry note that it's a bit hard to drink without some Coffee Mate. (Terrible, I know!) I will definitely give this a try. I'm a lover of kitchen science/chemistry, especially food chemistry. I look forward to seeing what I can get out of these beans.
Hi James! thank you for this video in particular.
At my cafe we only brew single origin coffees (for both filter and espresso) and have a particular bend toward washed Ethiopian coffees. We have played around in the past with seasoning espressos after brewing with just a few drops of a 20% saline solution (á la Dave Arnold) with enjoyable results. We've also added small amounts of a solution of isomalt to intensify mouthfeel, we've also played with isomalt in our iced coffee (a modified version of Windelboe's sugar in the iced coffee) but ultimately these techniques have never seen day to day service because of what amounts in my head to a fundamental lack of understand of my role.
I'm not sure if my job is to showcase coffees, I.E. source, brew, and serve them as best I can or if it's to make the tastiest drinks I can. is modifying a coffee post-brew somehow disingenuous? is it faking? or is it our duty to make the tastiest coffees by any means available?
I'd love to know your thoughts.
4:30 minutes into the video.
James: Let's use a filter-roasted Kenyan as base for this experiment.
Me: Oh boy, I can't wait for his expression when he tastes it :-)
Somehow, I thought I've seen this topic somewhere before, and I went back to check it and found that, indeed, Jonathan from Coffee Ad Astra posted in one of his blogs saying that he once messed up with the brewing water but found it amendable by adding bicarb afterwards. So, rather than playing a role directly in coffee extraction, bicarb may have more to do with the taste of it. And today, we have our Mr.Hoffmann, the business owner, the coffee professional, the yesterday champion, the necromancer, the fine UA-camr loved by his patreons and sponsored by fine companies, look into the topic! Chemistry is lovely, we should talk about it more Lol.
Love these kind of vidoes, ever since I watched your video about removing crema from americanos i've been mostly hacking my blacks that way. It's great that you put your ideas into motion and record experiments like this, big fan!
Why I bicarb my cup not my water... oooh wait, wrong channel. Haha - the Venn for this is so special!
Why I bicarb my espresso machine and not my cup
@@MrHamed99 Why I bicarb my mouth and not my coffee.
I have seen in many coffee shops where they serve a glass of sparkling water, (it could be soda water, which is basic whereas sparkling is acidic) with my espresso. Your video made me wonder if this maybe an establish thing or they are doing it for some other reason. For me I treated the sparkling(or soda water) like a chaser that I drink after the espresso which mellows the harshness in the throat. Anyway I don’t reckon it’s weird at all, some espresso are quite concentrated, and I would do anything to mellow down a sour espresso. It’s like adding water to whisky.
Kingeresident I can’t remember most of them, there is one that I remember, it’s called Dolce Espresso I think in Doncaster
Congratulations to 100k! Very well deserved!
Well, just went and added some sodium bicarbonate directly into my portafilter of a double espresso of my decaf coffee.
I use the Swiss Water version of the decaf, and I found it very sour. No amount of fiddling with grind and ratios would seem to make any difference.
But this does the trick. Will still have to experiment, and I know that adding it into portafilter makes for the most inconsistent method, but it works, and that is the most important thing.
Thank you James, oh so much, for teaching me how to make and enjoy coffee
in my house where we are all dairy free, most single origin beans we get split when mixed with soy milk, and adding a bit of bicarb can sometimes fix that, i think this is the same effect, but explained a lot better. but we always put too much in and can taste the bicarb, need to do the dropper thing. great video
I was so shocked at how effective this is i said expletives out loud in my reaction while alone in my kitchen.
Fantastic tip, James!
One of the few comments of someone actually trying it. Thanks!
Recently I've been making moka pot "espresso" using beans that are intended for filter coffee. The result is an intense, fruity drink, that is honestly a little too sour to enjoy fully. Some of that sourness can be balanced by allowing the moka to brew more of the bitter notes at the end. But the best results come when turning that fruity, sour, concentrated shot into a milk drink. The heated milk provides the sugar, which (as you said) serves to harmonise the acidity. The result is a cappuccino-style drink that everyone I've served it to has commented on being one of the best coffees they've ever had. And I'm a coffee newbie (hooray for lockdown!).
I think this opens up a whole other door for coffee lovers. Not everyone loves dark roasts, but they're what's predominantly used in espresso and, therefore, espresso-based drinks. But by changing your approach, and embracing the factors that compliment sourness, you can make drinks that massively outperform the traditional recipes for those people whose tastes lean towards light-roasts.
Experiment, dear coffee lovers!
Just got myself some fab Kenyan yesterday and as expected it’s incredibly sour when I pull a shot so definitely going to try this over adding sugar. Thanks James.
Does the high-buffer water create any precipitates in the espresso? What about the sodium, what’s happening to it and are you getting any salty flavors?
I did not taste salty flavours but added the bicarbonate directly to the grounds. It really changed an acid roast to a sweet, chocolatey well bodied espresso. I was amazed.
This is so cool. I watched this video a while back, when getting into coffee, but I forgot most of this info. Today I brewed an AeroPress and an espresso with Evian water, which is a very hard water. The espresso tasted amazing, the sourness of the light roast was toned down to allow me to enjoy the flavor a lot more. The AeroPress, however, was a little bit bland. I like it better with soft water. Can't wait to try this experiment with a V60.
Super cool video! In a field like coffee where things often feel very regimented and prescribed, I love that you're showing that there can be a lot of room for curiosity and experimentation too.
One question, as an owner/maintainer of the espresso machine you used: Did you flush the boiler when you changed the water? The brew boiler isn't large, but it holds a few shots worth of water and I could see it affecting the actual water makeup if some care isn't taken
Wow, This is really great! Thank you so much, James, for sharing this. This is the first video I've seen of you.
I did that, and I was quite surprised. Texture does change a little bit, but the change in my opinion is pleasant. I have to try making a long black now, that might be interesting ...
I used to add baking soda to a certain coffee drink I used to make. I did it specifically to neutralize the acidity in both the coffee as well as the cocoa powder. It worked pretty well.
I traveled through quite a bit of Italy in the late 80s and noticed in the coffee shops many people who ordered espressos put a pinch of a white crystal into their drinks. I picked up the container they were dispensing from and put a bit in my hand, low and behold it was salt. I'll be trying the bicarbonate tomorrow, sounds intriguing.
Also a chemist here, espresso is the most satisfying version of high performance column chromatography out there
Well, its rather a solid-liquid extraction than a chromatography...
@@rene3076 Unless the column he's comparing to is his digestive system 😆
That's really cool! I never thought about it like that.
@@rene3076 Solid - phase extraction (SPE) would be more accurate to describe espresso. It is chromatography in the simplest sense, a liquid extraction that passes through a solid matrix that can separate the solutes based on polarity. Solid-liquid extraction is more general, defined by the simple mixing of solid and a liquid solvent followed by separation of the liquid. Since there is no solute separation happening in the liquid phase, it is not a form of chromatography, and solute separation is dependent solely on misicibility in the solvent. This is more descriptive of a infusion brew. Liquid-liquid and Solid-liquid extraction are quantitative techniques for the concentration of solutes, think soxhlet extractor. They are preparative methods used before the separation techniques like chromatography. A good cup of coffee requires the precise separation of soluble components, i can only imagine how terrible coffee from a soxhlet would be, although strong!
Watching most of the videos from others, this really stands out which explained the properties in technical aspect. Excellent!
You are on the right track. Bicarbonate of soda helps release carbon dioxide at about 80 degrees celcius. I have added it to my expresso to the middle of the grind before tamping. As it brews thru the grind it produces a less acidic taste. Thanks for doing this video.
Hoffman, Brilliant. Canadian here. Might not be relevant to this specific video but about two weeks ago I commented on one of Hoffman’s videos, having just discovered him. I said in that comment that I feel like I could taste a hundred coffees and notice no difference.
Goodness was I wrong. I did not spend a single dime, Just listened to what Hoffman had to say. And wow, my coffee experience has changed. I’m still uncomfortable saying that phrase. But those simple alterations really made major changes in how much I need to add to my coffee before it’s palatable. It doesn’t need any improvement anymore, no sugar or flavouring.
Hoffman you’re a magician
(Scientist, Professor, mentor)
But magician
*Hoffmann
James Hoffman liked my comment😊 lovely. Also wow I sound like a fanboy. Idk I didn’t think an improvement in coffee skills would really improve my situation this much. Of course this channel teaches a lot deeper than hot beverages.
The point of buffer solutions is to *maintain* a certain pH range, keeping your solutions pH from changing to unfavorable levels. This is technically just adding a basic solution to raise the pH.
Apologies if i am asking something all to apparent but what about salt. You’ll still bring the PH up it’s obviously readily available and in small amounts in may actually bring out the origin of the coffee the same as it does for flavors when cooking.
Random thought: so salt (like ordinary table salt) changes your perception of coffee by reducing bitterness. Specifically, the sodium ion actually changes how the butter taste receptors react in your mouth, inhibiting them. When you've mixed in the sodium bicarbonate, you're releasing sodium ions into the drink (I think. My stoichiometry might be off, it's been a while). This can affect how you actually taste the coffee and might be the other "changes" you taste in the espresso. Thoughts?
Also, salt in coffee could be something to explore. I know a small pinch in the grounds has made some very cheap coffees somewhat more bearable for me.
Bicarbonate is actually forming salts with the acids, mainly sodium citrate, malate and quinate. Those vary in taste from "salty" (malate) to slightly sour (citrate) and somewhat bitter (quinate).
Sodium ions don’t generally produce scale. In fact commonly in industrial uses we use resin filters that replace calcium ions with sodium to prevent scale buildup in boilers and other equipment where heated water is needed.
Congrats on earning a Silver Play Button!!
I'm very curious to see how I like a more buffered shot, because high acidity is my favorite attribute of espresso. I'll drop another comment once I try it out.
Hello Mr. Hoffmann. A pleasure. Now adding sodium bicarbonate is about the best agent of alkalinity possible. No better choice to make so far. I can add this to your info:
By adding bicarbonate to your coffee after extraction you do not change the extraction process itself but you cause more of the acids already present in the cup of espresso to stay in your body beacause they are already bound and neutralized and thus not perceived as acid anymore. So everything you explained is actually right, but adding bicarbonate can better the taste of acidic coffee at the expense of more acid accumulation in your body on long term conpared to not using bicarbonate.
I love this weird vintage footage in the beginning and also love your coffee science series! please continue.
What would happen if you inoculated the coffee grounds directly with a dose of sodium bicarbonate (bicarbonate of soda/baking soda), so that it gets extracted with the coffee in the portafilter?
Interesting.
That would be pretty tough without a really nice scale. He is using 0.13 grams of sodium bicarbonate per double espresso. It would be interesting to be able to do it to help keep your machine scale free, though. pH can definitely change the solubility of certain compounds as well as obviously directly affecting flavor perception. i have a feeling that the two espressos he made with altered water chemistry may be significantly different because of the altered extraction chemistry in the first vs. just neutralizing some of the acidity in the second coffee.
Water chemistry and pH is always monitored in beer brewing as a way to control the extraction of tannins that lead to astringency (as well as other reasons), so I suspect pH control during coffee extraction could be equally important.
The AWS LB-501 scale is a really nice scale that measures down to 0.01g and up to 500g - Plus it's not all that expensive, though harder to come by in Europe.
My thoughts exactly!
James, what about adding bicarb to the top of the puck? Wouldnt that a. Solve the lime scale problem and b. Still give you the same results?
anyone tested?
i have been adding heart salt (higher potassium chloride).....just a small amount as I use filtered rain water and that would have next to zero minerals....now i will try it with baking soda and see the difference...adding salt gives my coffee more body!
So I saw that you were using a Sage/Breville machine for your tests. Breville states that they do not recommend water from reverse osmosis filtration for use in their espresso machines because it lacks the necessary mineral content needed for their sensors to operate. So I'm adding a splash of tap water to my tank each time I fill it up with water form my large filtration system.
All that to say, I have no idea what my water chemistry actually is and I was one of those who wanted this video to be THAT video about water chemistry. :D
Congratulations, James, on the 100K milestone. You're seriously knocking it out of the park content wise!
The reason they suggest not using reverse osmosis filtered water is because it's really corrosive and doesn't make good tasting coffee.
Use the 'water hardness' strip provided with the machine, then go into settings and set 'water hardness' accordingly. It'll determine the cleaning cycle and internal filter change intervals.
@@space.youtube actuality they state quite clearly that it's about their sensors and taste. www.brevilleusasupport.com/bes900xl/troubleshooting/ see the section about the importance of water.
As for the corrosiveness of the water, I'll have to look into that. They do not provide a test strip with the model I have here in the US.
This is brilliant, for those of you who dislike milks in you coffe this is a great way to round out the sourness of a shot I tried it and loved it.
At the shop I work at, we make a form of iced americano using Topo Chico Mineral water, and it makes the espresso wildly calmer tasting. I want to try adding a bit of flat mineral water to an espresso and tasting it to see if it tames the acidity.
I mentioned adding SB(baking soda) to your coffee in a previous video's comment section. It has been done here by many for decades. Adding just a pinch to a pot of coffee really can round out the flavors.
It would have been interesting if you measured the PH of everything as you went.
"Oooh", with a smile. Only James could pull that off. 🤗
Thanks for the interesting insight James. Now time to find a coffee shop that will let me play with their Machine
I really appreciate that you link the name of the music used in your videos. Oh and the video is also great! Cheers & greetings from Germany
I love the intro of this series so much!!
It works, you fixed my precious coffee, thank you so much, so much more flavorful and enjoyable
Potassium Bicarb is a good substitute for Sodium Bicarb if you are on a low sodium diet. Some "experts" also use epsom salt and calcium chloride in coffee water. I am not interested in manufacturing espresso water but I may try some KHCO3 in the cup.
This video is great, do one where you really talk about the influence of the minerals on taste! I'm sure there are more people interested in a bit of extra chemistry
haven't people been mixing bi-carb with grinds since drip machines were around? you can also mix directly in espresso grinds and along with it's buffering characteristics, it will also produce more crema. adding a pinch of baking soda to the grinds feels like a cheat to not just buffer the acidity but the grocery store coffee and blade grinder too, but the way you put it feels more sophisticated.
100k subs congrats!!! keep up the good job
Love this test. Could you possibly do a video about the concept of freezing and/or refrigerating beans? Whether or not it preserves flavour and extend expiration. Maybe some blind tests?
This is absurd. Coffee snobs will have you roast a Kenyan barely to the finish of first crack to preserve it's "character", and even though it tastes like battery acid you're supposed to pretend to like it if you want to be in the coffee club. Bicarbonate of soda tastes AWFUL. Try some just dissolved in water by itself. We're supposed to improve that precious Kenyan that we worked so hard to make as acidic as possible by adding an awful tasting base to it? I've got a tip - try a Guatemala Huehuetenango roasted halfway to second crack. It's called balance.
Would be keen to see if you measure the pH of espresso before and after adding sodium bicarb!
Try a sour shot after chewing a tums. Should be equally effective
Never thought the worlds of fishkeeping and espresso would intersect, but here we are
A lot of things can be done to make the coffe taste better or different. Adding strawberrys is one. Adding sugar, honey or milk is one. Adding bicarbonate is one. It's not revolution but it is interesting. I had another idea. If you could pull a shot along a cut-open cable with just small compartments - you could rebuild your espresso again by mixing it all up - or by mixing it up with different proportions... What would make it a little bit like an audio equalizer - but to the espresso.
Mind Blown! I have to try this. Thanks James!
Such an interesting video! This is the video that prompted me to subscribe!
Love this! As I've been exploring espresso more, I find that ones that I get from most cafes are extremely sour... I might have to sneak some of this along with me.
This is so true. Every other espresso I get at a coffee shop is sour. Do they just not know what they are doing??? I read that sourness is typically caused by low water temp and/or too fast of an extraction. It’s very common though. I thought it was just poor quality beans until I looked into it more
Try adding anhydrous buffer on top of the portafilter puck before extraction.
You can bake the bicarbonate and make a stronger base. You could also add it in powder form in the portafilter
I often drink a splash of sparkling mineral water before a shot of light roast espresso. I have found drinking the mineral water before the shot mellows the initial acidity and the lingering bitterness of the espresso, I presume this must be why. Another benefit is that it cools the mouth, which can make drinking a fresh shot a little more pleasant to the tongue.
Very interesting. I worry that lesser shops would use this to compensate for under-extracted and poorly brewed coffee.
It doesn’t disguise quality, defective roasts or green coffees will still taste bad
I always add mineral water to my expreso . It almost brings out the flavour more idk why. A bitter shot becomes really well defined and balanced.
Wow, this hack is amazing. I've just got an old Pavoni and keep getting super sour coffee. I don't have a grinder, so probably getting a not perfect grind and underroasted coffee (supermarket stuff unfortunately). Reducing the acidity with this makes a huge difference
Just rediscovering an old Pavoni Professional these last few days which my parents were given years ago - it was gathering dust, but I remember having used it years ago and it made pretty weak sour shots (and I didn't have a clue about coffee back then). I'd say it's most likely the supermarket pre-ground coffee as you say, which is not quite fine enough - but more likely over- than under-roasted, especially if the texture/thickness is good but it's just too acidic.
Thanks James for this fantastic input. I was wondering, can we simply add the soda powder like sugar in order to get to the same point? we wouldn't have the "added-water-bias" then.. I'll defently try this in some way at work
I think you'd have to have a very accurate scale to accomplish this, as the prescribed dose and strength (4g of water at 3.2g/liter) works out to just 12.8mg of sodium bicarbonate. As most brewing scales only have a sensitivity of about 100mg (0.1g), it would be difficult to get an accurate and repeatable amount.
Hi im your biggest supporter here in KSA im from phillipines im always watching your vlogs thank and will support all of it
Will definitely try this out over the weekend!
Have you tried adding powdered bicarb to the ground coffee in the portafilter?
I did it an the result was spectacular. Less acidic, sweeter and full body with a rich crema espresso. Just don't overdose it since you still want to keep some slight acidity.
I have not tried it yet, but as a chemistry student i have to say: Sounds great! :D
Kava "Acid Neutralized" Instant coffee has potassium hydroxide in it (suggested buffer below). I wonder how much KOH would deliver the same acidity as your 3.2g bicarb to water without the bicarb taste.
Admittedly I don't make espresso at home since I'm broke and its been a long time since I've taken chemistry, but if the whole idea is to add alkaline water to neutralize an espresso's overwhelming acidity, if the amount of buffering solution you would need to add to round out the sourness is so much so as to significantly dilute the espresso, why bother with just a buffering solution? By adding a strong base such as sodium hydroxide or calcium hydroxide to the espresso, perhaps through titration or a dropper, couldn't you get the same effect of rounding out the sourness without as much dilution?
Also, on the off chance that James Hoffmann reads this comment, James, could I suggest a weird coffee science video exploring what effect if any variable RPM on an espresso grinder has on the taste, texture, and overall quality of the final espresso cup?
My first thought was to use a little bit of NaOH - lye - in solution rather than bicarbonate. That should be completely taste neutral, at worst adding just hint of salt. Of course, that won't mean the effect ends up being taste neutral. In Norway it's easy to get food safe lye as it's used in preparing some traditional foods.
A super easy way of measuring small amounts of concentrate is by using little 10ml syringes with the millilitre markings up the side. It's how I mix up my jugs of water that I use for brewing and in the machine.
I tried it. The Bicarb of Soda definitely changes the flavour of the coffee. The acidity was not completely removed.