Did Science Just Reinvent Espresso?

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[@morebagful]

Hi James. I wanted to say thank you for making such a well-balanced review of our work, and also for helping to propogate the ongoing conversation about this. I'll be following the comments here with interest.

[@Thamanizer]

Lots of appreciation from this physics grad and coffee drinker! I really appreciate these sorts of wholesome, multidisciplinary papers: the balance between theory and experiment was absolutely on point here. It was a great and educational read.

[@DrDankoff]

Evidence based shot design, thank you for bringing some knowledge to an art. It can only be elevated. And thanks James, your words are like the interpretation of an article by a senior physician in medicine, filled with the pearls that make pure evidence relatable and creating real world usability.

[@fanothecardgame9996]

Hi James, thanks for your paper. I enjoyed reading it. I can't help but wonder if the turning point in EY% is the emergent property that, in truth, defines a proper espresso. Could this property (micro-aggregate formation of fines) that allows for a creamy, yet well extracted shot, without crossing the over-extraction line, be the reason espresso migrates away from filter coffee? I wonder if the conversation can be two-pronged: (1) as James Hoffman suggested, how can we control the flow of water into the puck to be more thorough and cover a greater surface area and (2) how can we harness the emergent property to make excellent espresso more reproducible. Can this be achieved by layering coffee grounds such that the stratification artificially reproduces this effect? Would love to hear your thoughts.

[@morebagful]

@@fanothecardgame9996 No worries. Glad you enjoyed. The honest answer to your question about whether the turning point defines an espresso is that I am not sure. That being said, I do think it is a more useful definition than the presently accepted one by SCA, which, I think, is rather outdated and even misleading. An interesting point about stratification. With rather minor modifications, my code can actually simulate what we should expect from layered pucks. It'd be interesting to see what comes out of that. I need a willing grad student to try these things out.

[@MarKeMu125]

I wonder if there's an ideal puck depth for extraction, and inversely an ideal puck cross sectional area (or even ideal shape) for a given measure. I imagine they'll be a crossover much like there is with pressure where a deep puck could have better extraction (every ml of water travels through the most mass of coffee possible) but one that's too deep couldn't be overcome by the pressure and just jams. This could lead to different (thinner & taller) basket / portafilter designs that use less coffee but obtain even greater extraction, and could be made to fit on existing group heads etc. Would be an interesting experiment.

[@jedidiahsolomon9952]

love the scientific term:"tasty point"

[@michaeledwards6455]

I think there is a sugar level in foods that manufacturers call the "bliss point". I would argue to swap these names. "Bliss point" works much better for me when we're talking coffee than "tasty point". Another captivating video. Thanks so much James.

[@Throughly1]

It's nice we have a tasty point. Maybe scientists are not too far from a tasty line or zone. Who knows?

[@brandonbenjamin9452]

Jedidiah Solomon I thought it was tasting point

[@stuffnuns]

Best scientific term since “The Goldilocks Zone”.

[@MelindaGreen]

@@stuffnuns My favorite scientific term is "Sausage instability".

[@MarketingGuy]

At the end of the video, James reminds me of my overly excited high school physics teacher who himself was so excited about physics and desperately tried to transfer his excitement to the students.

[@jameshoffmann]

haha! I will take this as a compliment!

[@dustinandrews89019]

Did you have Mr. Niznick (sp?) too? He made Bill Nye look mellow.

[@bluppflash]

aeugler Did ist work? ;)

[@ehtikhet]

The best teachers! I’m guessing you remember particular lessons and experiments?

[@MarketingGuy]

@@ehtikhet no.

[@TommyFugitive]

I frequented Tailored in Eugene when I lived in the states. I would sometimes chat with Chris Hendon because we were there at the same time so often. These shots were really good. When the barista told me it was a 15 second shot, I glared. I tried it. It was good. He pointed at Chris. Chris looked pleased. He gave me the elevator pitch of the science. I got this kind of shot nearly everyday for the summer before I headed to Europe. I was still baffled by the explanation and still am, a bit.. The flavor is really good. I did taste a difference between the old, long pulls and the new pulls. Some flavors were lost, but other flavors appeared. I don't know if they were adjusting the bars yet, as this was two years ago and they were just trying it out for the first time. I bet they've improved the kinks. It's definitely worth having a go. Chris also convinced me it was ok to freeze coffee if I wanted to keep it a while. He said the beans would preserve just fine. He turned out to be right.

[@mishtram]

I can speak anecdotally, but I’ve been a frequent flyer at that cafe in Eugene Oregon (Tailored Coffee Roasters), and I can speak that their espresso has always been the best I’ve ever had. I’ve spoken to the baristas and they’ve always said that their espresso was pulled faster and different. Thanks to this paper I understand what they mean now. I’ve also met Dr. Hendon once - super super smart. So excited for this video James!!!

[@SkaCorePunker]

Hey! I live there! Will have to check them out!

[@codyvanvoorhis6486]

I miss that place a lot :(

[@themedicinedan154]

I really hoped this was about Centrifugally Separated Turkish Coffee.

[@user-iz3hd6mt1h]

Me too

[@panp1222]

boy do i want to see this

[@mildlydazed9608]

Isn't half the goal of Turkish coffee to have that mouth feel?

[@digitalinversion9500]

funny thing I actually build a system in my university years to do exactly that. The result was not as satisfying as the original thing

[@corwinblack4072]

@@mildlydazed9608 Probably, but if you get clean ibrik (filtered) you might found out that its about best coffee you ever had. Except you will need to do it yourself.

[@christellez3628]

WE've been pulling 15 second shots at our cafe for the past 4-5 month; 16g input/30g output/15 second brew time... 5-6bars of pressure. Excellent results!

[@zeropuckprep]

19.5g => 24g out is one of my faves no research paper necessary

[@cz5696]

@@zeropuckprep 🤔

[@myname-mz3lo]

@@zeropuckprep ratio is really just down to taste. you just preffer ristretto

[@anasghandorah4354]

TEST SETUP Essp. Machine: GS3 AV Pressure: 6 bar Grinder: Mahlkonig E65S Basket Size: 14g Refractometer: ATAGO Brewing Temperature: 93.7 ºC Coffee Beans & Roast Date: RED BRICK Espresso Blend (20/11/2019) Brewing Water: 3rd Wave (Espresso Profile) 167 PPM (TDS) Scales: acaia RESULTS (1) Water/Coffee Ratio: 2.14 Grinder Setting Range: 0.55 to 1.1 Peak Extraction %: 20.63 at 24.5 sec with 0.8 Grind Setting (2) Water/Coffee Ratio: 2.84 Grinder Setting Range: 0.8 to 2.05 Peak Extraction %: 22.66 at 19 sec with 1.7 Grind Setting Best Tasting Recipe: 2.05 Grind Setting, 14g Dose, 39.9 Yield, at 16.5 sec, with 7.5% TDS (Strength), and 21.37% Extraction Yield NOTE: I have had a home subscription with SQUARE MILE for a while and so far have consumed around 8kg of the RED BRICK Espresso Blend. RED BRICK never tasted this good. To James Hoffmann, We cannot thank you enough for your inspiring dedication and generous contributions to our lives!

[@smwillia]

I love how this paper will push people into the "less sexy" part of the scientific method, the replication studies part. That is the area where the nailing down of the facts and methods are made.

[@Seblo_]

I tried this at my cafe during a quiet period. I found very similar results to yours, the texture definitely suffered a little, but the method still produced a nice cup. I found it hard to grow accustom to however... Especially when you compare it to what I'm normally tasting. It had a lot of similarities to a V60 in terms of the clarity flavour in my opinion. My recipe: 16g in 38g out @ 15s Equipment: EK 43 Black Eagle PUQ Press 2 Coffee: Pablo & Rusty's 'Trailblazer' (seasonal blend)

[@MrThedalaillamaknows]

Fuck yeah P&R make incredibly great coffee.

[@krist6028]

A couple days back, I was in a very small Maine cafe (way off-season), in a very small town, and the owner already knew about this study and was excited about learning more. There is hope for humanity.

[@samsturdi]

I’ve been a barista for 13 years and this is the most thought inducing conversation for a very long time.

[@willyp618]

“This is not a recipe to remove the barista from the process” *Perger has left the chat*

[@dreamvisionary]

I've got a low-end home setup consisting of a Gaggia Classic and a Sage BCG600SIL. Having watched this video, I checked the brew head pressure and found it to be 10 bar. I typically use 17 grams coffee for a 20 seconds 40 grams pour and to be honest I have struggled with pulling a good shot, but lowering the pressure to 6 bar and grinding slightly coarser to achieve a 15 second for 40 grams yields a much better shot. I pretty sure it would not be up to the standards that many who watch James' videos would be satisfied with but it's a considerable improvement for me. I suspect at 10 bar I was getting puck compaction and channelling, as I noticed the pour speed increase over the length of the pour. Maybe this has some value to us low-end brewers.

[@81caasi]

I have a Classic(w PID controller installed) as well with a Baratza sette 270. I lowered the pressure from 15 bar to 9 bar for 17g dose, then to 6 bar cause I switched to a 15g dose/basket and needed a much slower flow rate for the smaller dose. I aim for a shot between 15s to 24s. My grind is close to the finest setting on the Sette to the point where distribution/even flow are a sensitive situation and I could only get consistency with a distribution tool(using a naked portafilter). I find these faster shots are less sour and plump enough, but I'm still looking for the sweet spot with natural sweetness/flavor. I'm close but not there yet. I'm still searching to find this cross point where the grind size is the finest to slow down my fast shots but doesn't begin to mess with even distribution.

[@TimTeatro]

I'm a PhD student so I have very modest equipment. My background is in computational physics, applied math and control systems engineering, so this paper is well within my wheelhouse. I taught myself to make Espresso a couple of years ago by standard doctrine. The timing of this video and paper, for me, is delightfully coincidental-as I've recently been discovering some of this on my own-just by toying around morning to morning. One morning I forgot to adjust my grind and noticed that I got a much nicer americano than expected on a looser grind. I started thinking about the tradeoff between channelling and surface area and postulated this sweet spot. I can't wait to read the paper. Thanks so much!

[@TheDenisedrake]

My taste buds are dull. I probably couldn't tell a delicious espresso from strong pour-over. I'm just here for the smooth voice and the knowledge that nerdy people can be lovely and beautiful. So for that, I thank you.

[@bakhitalketbi9460]

when you brush your teeth try brushing your tongue too

[@stefan2901]

The more you know the less you know. I kinda have the same oppinion about my taste buds, but then i remember: - once pulled a shot so good i was smiling like an idiot, could taste the forest fruit notes so clearly, it wasn't even described in the coffee description, some local blend based on brasil; - once had an aeropress at a coffee shop, actually had more at that shop but this one was something else, again very clear fruity notes, peach, nicaragua i think; - at another shop they were testing some speciallity/expensive coffee for a future contest and they gave me to taste it in spoon, i recognized the lemon but i wasn't sure about my taste buds, and then the guy there told me first note is lemon :o Anyway, i don't think even good baristas can pull 100% consistent shots. I can recognize good shots from bad ones, but rarely taste some notes.

[@shorttimer874]

The same, chemo is unkind to taste buds

[@cdgonepotatoes4219]

@@bakhitalketbi9460 hey, it's great againt bad breath

[@TheDenisedrake]

@@bakhitalketbi9460 That's a good idea. I could also focus more on what I'm drinking.

[@jean-simondesjardins2819]

You are the only KZbinr that gets me pumped about uniformly shredding burnt berry pips. And it isn't unpleasant at all! Thank you for the video and your pragmatic approach to the paper and news.

[@BensCoffeeRants]

I usually do cappuccinos but I've had really good results with shots that ran super long due to a way too fine grind, and good results with a way too fast shot (too course). It bugs me that some people just throw out a shot of espresso because they think it didn't turn out good, especially if they never even tried it! If it's not good and you're not anti-dairy, add some milk and/or sugar and it's still salvageable :p People worked very hard to grow and prep that coffee. :O

[@omniplank]

I've honestly been waiting and hoping you'd make a video about this. I expected a level-headed and well-informed response and you, of course, delivered. Thank you James!

[@ericgoldstein2051]

sometimes i just turn on your videos to be soothed by your voice and to relax. i then either start to cook, do some exercise or just have a smoke on my windowsill. i also love your content and at other times i just binge your channel, including rewatching older videos, for hours. thank you james.

[@GraysonCarr]

Is there a chance Nestle already knows this? I think I recall there being some questions a while back about how Nespresso pods are able to use so little coffee and get such high extraction? Some people even guessed they might be mixing in instant coffee, but that was proven not to be the case.

[@alansaxon]

Thats an excellent point...I think I measured it at something like 6.3 grams. damn tasty too!

[@blzt3206]

Nestle's market cap is 317 Billion dollars. They might know a thing or two about extraction.

[@tim_f_jones]

Heard an interview with the author of the paper last week and capsule systems were brought up. He said that capsules were extracted at very high pressure (15-16bar) so that approach was quite different to the recommendations from the paper

[@5naxalotl]

as i understand it, capsule systems incorporate a restriction, like pressurized basket machines, and similarly the pressure seen by the puck is pump pressure minus restriction pressure. the reason for the high pressure of these systems is that high pressure plus high restriction means that the grind has little effect on the flow rate. it also means the pressure is too high to use a non-pressurized basket without difficulty, unless there is also flow metering ... in which case the pressure applied to a coarse puck is way less than the 15 bar rating, which is merely the maximum pressure the pump can apply as flow decreases

[@nitramluap]

They taste like dirty water. Wash your mouth out!

[@davetellier4063]

Happy to see that i am not too crazy... La Pavoni Europiccola with localy roasted Ethiopia Sidamo beans 14g in, 36 out (coarser grind) 10 sec 1.5 bar, 5sec at 4bars and around 10-12 seconds at 6-7bars. I use and like this recipe since 1.5 years now and was thinking that my coffee taste was a bit odd... Thanks for the great content!

[@Sprometheus]

Great to hear your thoughts on this James. As a natural skeptic, but capable of being able to try this at home I spent some time making some shots within their parameters. Similarly to your view, I did find the shots of 15g in and 40g out in 15 seconds to be surprising pleasant. I expected clear under extraction flavors, but they were sweet and had very high clarity. But I didn't find them capable of surviving an onslaught of milk. Like you mentioned, these things may vary a lot based on the coffee, and likely the equipment used (I used a Linea Mini and a Mazzer Mini). It's interesting to hear your take aways, and I after hearing your thoughts I do wish I could go back in to my video and maybe talk a bit more on the espresso side and forgo a the bit on environmental and economic impacts (yet are still relevant, but tend to be more polarizing). I think the topic of even flow like you mentioned could definitely be something fleshed out a bit more and plan on digging into that a bit both on and off camera. Thanks again for your sharing your insight, hope to see you at Expo in Portland. If so first piece of Tiramisu is on me.

[@davidf888]

In theory if you had a super wide basket with very thin layer of finely ground beans would it make a good even shot? Or if you had a compartment that filled up with the full amount of water and had a tamping method that would push it down all at once into the group head.. Would like yo hear both your thoughts and James on my two ideas

[@cristim9779]

Why don't you make a video about this new recipe and taste impressions?

[@Sprometheus]

cristi m I did in fact make a video about this, it’s the most recent one on my channel.

[@Sprometheus]

David f theoretically those sound like they would crate even extraction. The tricky part would be having to complete design an espresso machine like one of these from the ground up.

[@davidf888]

@@Sprometheus yes you would need to remake every single tool and machine used for espresso making if you make a new much weider size basket but if it works it will be worth the investment. Not saying that every coffee shot needs to switch over but any new place that opens or shops that are planning on upgrading any way can switch over. And the idea if a machine with a compartment that fills up with water and pushes it down mechanically right into the puc will only need a change in the actual espresso machine which companies do anyway all the time when coming out with a new series. Only question is well these methods actually work and if they will it is worth investing in

[@MrSramozz]

I just love when people think of a theory about something, flesh out their thesis, and when testing it out, figure out something that is as ground breaking, but completely different than their original theory. This remind me a lot of Dave Arnold theorising that is the science of cocktail making, the shape and kind of ice used in your shaker didn't actually matter, and when he tested his thesis, he actually found out that yes, in fact, it really does matter, and the best way to use your ice in the process of shaking a cocktail was to use one big block of ice, for displacing and mixing your drink well, and a bunch of smaller ice shards around, to act on the percentage of dilution. As always, I loved your video, thank you.

[@jameshoffmann]

Reminds me I need to buy some Cocktail Cubes!

[@christopher.h.hendon]

We've got to adapt our hypotheses based on new data. Our OG hypothesis was that you'd grind finer and get more out. 🤷🏼‍♀️ I guess that was not a good one in hindsight hehe

[@kjeksomanen]

I thoroughly enjoy how you're able to communicate complicated topics succinctly!

[@jasonputt8787]

I saw a couple articles about this and just knew I just had to wait for you to make a video about it!

[@markwaring3638]

AGAIN with the dope and funky intro. The wholesome coffee content I need. Keep up the great work sir I owe my tasty morning coffee to you.

[@BurgundyandBlue1111]

It is amazing how much science and engineering go into food and drink preparation. I believe the same things that drew me to chemical engineering draw me to watching your videos (as well as a bunch of food videos). I appreciate the places in life where science and art coalesce. Thank you for another very interesting video!👍🏽

[@jordandollar4141]

Thank you! I have been so skeptical about these articles!

[@jameshoffmann]

They're worth reading. And testing!

[@carlosfelix8047]

Love the video and your approach James! The more we think about these aspects the closer we get to understandig what we're doing and having a perfect coffee in the morning. Thanks for the video!

[@oliphab7468]

This was a great video! As someone who knows more about science than coffee, your explanation of how science is done, and what we should learn from one paper is great!

[@fredrickyamashita2305]

The first person that popped into my mind when I saw an article about this was you.

[@dan110024]

*read paper....waits for James to release his thoughts* *video pops up next day*

[@neoalex]

I literally hit him up on twitter before reading the paper hahahahahahaha

[@4ksandknives]

James is the peer reviewer that carries weight!

[@BBB_025]

This is one of my favorite videos of yours James! Very well done!

[@benjaminlee1089]

Every video keeps my interest and I learn. Thank you for providing amazing content!

[@Ahkuji]

I was waiting for this. I saw the articles, and was thinking "Alright, I hope James sees this and tries it out."

[@whoissb]

Perhaps a takeaway from the experiment is that manufacturers should make a wider and shallower portafilters/baskets/groupheads so that you can put enough flow through the puck with 18g-20g of coffee in 15 seconds to produce 1:2 extraction. Hello 70mm basket?

[@MarKeMu125]

Not read the paper, but logically I'm not sure why you'd want to do this... A thinner puck would mean each ml of water travels through less coffee leading to less extraction? I feel a narrower setup would lead to higher extraction especially with working with 6 bars as it would dramatically reduce the chance of channeling, however they'll be a crossover where there's too much work to get through the puck.

[@ReluctantRoboticist]

Thanks for another well balanced and thoughtful explanation of your understanding of the original paper and your extensive experience, @jimseven

[@yuugatenshi]

Just what I hope to see you discussing when I saw that paper came out!!! Thank you!!!

[@mishtram]

I met one of the authors when I went to Oregon!!! Super cool to see this vid!

[@AnteUp34]

I knew the moment I saw those papers that I would have some great videos from the coffee authorities to tune into. Thank you James.

[@danielcohn6884]

Great work James! I emailed you about this a few days ago, and like clockwork, you've already put out a thorough video on it. Excited to see where it all goes!

[@zzz3339]

Darn it James, you've interrupted my watching your older videos with another quality upload. How will I decide which to watch first!

[@danishskiwarehouse]

Impressive gerund use, Tsunimo!

[@fadelpw511]

Literally happened to me with the aeropress video, just start watching this channel a week ago

[@deatheater1900]

Thank you so much for covering this. I look forward to seeing what may happen in the future with this paper

[@krimke881]

If coffee shops around the world don't jump on this wagon, they are missing out a huge opportunity. If you can make tastier espressos, with less grounds, you make more money. The "few" who wants that textured body espresso from a 20sec pull, can have that, and the other 90% espresso you make during the day for lattes etc, you do the new way. I think it's a no-brainer. :) ✌️

[@Psysium]

I love the discussion around this. I'm actually really into the minor environmental impacts. My sister went to a coffee farm in Guatemala and they couldn't use their own beans because they were too valuable. And the shop I work at dumps *so* much coffee. And I think about it every time I see a gallon go down the sink. Each little percentage point helps!

[@iangibson6015]

Outstanding resumé of the whole thing James.

[@gildardo]

I'm so glad I found your channel. Good stuff.

[@OwenL2020]

Was waiting for this video since the article/paper first came out.

[@joshannunavis5441]

I would love to see this tested in your next dialing in espresso video. I read some of the news articles that you spoke of and because of them kind of dismissed the whole idea. Back to the drawing board! Thanks for another informative video!

[@MattPerger]

If only someone was working on that grinds distribution and puck longevity problem...

[@Daniel-dj7fh]

grinds distribution in the puck? get the grains frinded down to perfect cubes and sort them out and you'll get the most compact order. don't hammet the puck on a solid surface to keep it from breaking, or get one where the crystall allignment in the material is ordered to withstand forces implied in hit direction

[@bendavis268]

Matt Perger really looking forward to seeing your new gizmo. 🙌

[@willd2609]

Matt Perger eyyyyyyyyy

[@calebgodard4554]

Thank you! I was surprised when I saw some of the headlines and am thankful for this excellent explanation...

[@sirclemeni1]

There are countless papers about l/s extraction for industrial use, but basically none for culinary use. Nice to see someone do the first step into unknown territory. Hoping for more to come!

[@theismathieu]

I’ve been using faster shots between 16sec to 19secs at WBC and was very pleased with the results. The lack of mouthfeel can be mitigated by using a fresh roasted coffee that didn’t totally degassed. Prof Hendon visited our café last year and did a lecture about this topic. We then tested immediately the fast shots. Surprisingly the coffee that tastes great were the washed. The Natural were better with slower shots.

[@e.jacktaylor4053]

Impressive, James. Very interesting presentation and report. This is both the science and the lovely art of great coffee, especially great espresso. Thank you for you diligence, positive attitude and good humour. Best, Jack

[@mr_glasses]

I was waiting for this video. Very interesting stuff. :)

[@connoringle8153]

I saw this news article pop up on my Google news feed and love that you're so on top of it, and I'd also kill to see a more comprehensive approach to decaf espresso. I love decaf (even though I'll have like 10 shots of regular a day) because I know how amazing decaf can be. I understand it's a totally different animal and I feel like that's why so many people are biased against it (since it can be rather tricky) but if there was a reference to how exactly it's different and how to approach that I think it would make so many people so very happy.

[@bobbieglon8291]

Connor Ingle True!

[@FrankStatik]

Happy to see you have done the test! After reading the paper Monday I went back home after work that day and immediately went down to 15g ish in my 18g basket and a coarser grind and my first shot was an amazing tasting shot at 38g out in 14sec ish. Then some later were shots were less successful and channelling a tone but kept playing with this theory the whole week and still did amazing shots! I think this might be my new way of doing espresso for a while... Less about the "classic numbers" and more about the taste in the end...

[@madcat2709]

Love your videos! Keep up the great work!

[@PetrosArgy]

I will be looking into this myself with my flat burr grinders (I have two commercial units) and my commercial lever machine. Like one of the other commenters noted, Illy has standards that vary dramatically from what I hear so many people talk about in the US - namely the 7 gr shot. I was directed twenty years ago by the Illy rep in Poland to dial in my machine based on a 7-8 gram portion of coffee. I have stuck with this ever since and consistently get nice, rich, syrupy espresso, usually better than any local cafe serves. Some thoughts to maintaining pressure on the puck would be to use slightly undersized baskets to maintain preload on the puck as it dissolves or to redesign the portafilter to incorporate a spring loaded, floating basket which could maintain an even upwards pressure on the basket as solids dissolve away. Thanks for a great video!

[@simonduster67]

I'd be curious to look at the history of pucks. As a mechanical engineer, I feel like there are better ways to get 'even' flow through the entire puck than just having water forced from the top to the bottom of the puck. Just a thought....

[@cdvax11]

Over at Kruve that have proposed layering of the pick by grind size in the way a sediment filter would work. Fine grounds on the bottom, a middle size, and larger grinds at the top with tamping between each layer. Of course, keep out your grain of salt since Kruve makes equipment for screening coffee grounds.

[@trevorreader4715]

Maybe a sort of inverted cone-shell with a conical insert to distribute water even inside. This should minimize channeling while still retaining a consistent thickness of grounds. The primary issue is being able consistently form the grounds to a uniform shape/density.

[@sunilsanghani1807]

Fantastic explanation of the paper James!. Since reading the paper, I've moved slowly from finer to coarser grinds and I think that there is a merit to it. For example, I've gone on a Breville espresso machine from a grind setting of 3 to 5. In general, I find that at a coarser grind, it helps release the complexity though I'd qualify that by saying it also varies based on the roast. As to evens of flow, I am still working on that and don't have appoint of view. But then again, here in the US, coffee beans complexity has gone to a level that has taken way from the charm of enjoying the simplicity of espresso, perhaps something that the Italians have still retained. Just subscribed to your channel. Love the effort and passion you put into the content of your videos!

[@CDYTW]

Always love the hard science/food crossovers

[@yellowecho]

Great content! I'll do some tests with the Niche and Robot and report my findings.

[@robertneu279]

Great perspective! I use a conical but grinder and tried it out. Surprising results. Less complex, more consistent pulls.

[@ihcelee]

Thanks for the post, refreshing to see someone retest the experiments (an important part of science!) Especially after reading the hype of journalism who were unhealthily presenting the information to the public. Encouraging people to do the homework and be somewhat skeptical is much better approach to education (thank you!). Hopefully opens up further experiments and knowledge globally, I've started to test this on my equipment. Happy drinking all!

[@Hoot0wl]

Thanks for a great easy to understand review of this apparently controversial to some article. I have a superautomatic Jura and have started playing with grind settings, powder volume and water volume to try to tweak the flavor of my shots and I think these points you are making are helping me with this. I never changed any of the factory settings in the 10 years I have had this machine and the results are surprising in that I am improving the flavor of my shots even on a superautomatic. Thanks again...

[@bobbieglon8291]

As one who loves coffee and loves research, this new perspective on coffee is welcome. Maybe interesting changes are coming - Go Science!! Thank you, James, for including the link.

[@tonysicily2687]

Loved this post, subscribed immediately, now about to dive into your other videos. This happens in the brewing (beer) industry. channeling is the biggest problem in extraction of the malt.

[@josephs9600]

I was hoping you'd cover this!

[@Raggo12345]

I'm just starting my journey. When I'm ready, I will test this. Very interesting video!

[@chinchorrero]

Thanks for the video professor Hoffman (Great reporting)❤

[@danrazzaia3152]

I've been looking forward to hearing your take.

[@benrussell1476]

this style of video is great. i like the in depth science.

[@FaithPvP]

I originally watched this video a few months ago and thought it was interesting, but quickly forgot about it. Tonight I was recommended Lance Hendrick's video on the topic and one of the things he focused on a lot was how much easier it is to get _repeatable_ shots using the coarser grind + lower pressure method the paper described. It's something I definitely want to try when my Flair arrives, as I'm sure my hand grinders won't consistently produce uniform enough grinds for a more traditional shot.

[@mikairu2944]

+1 lmao, same story, save for the fact that I sold my Flair and instead plan on making this with my newly bought Barista Max. I'll have to adjust the grind size to emulate the 6 bars I guess

[@hshooker5761]

@@mikairu2944 Actually one of the takeaways of the paper is that adjusting the grind size to emulate 6 bars would take you to an altogether different place.

[@mikairu2944]

@@hshooker5761 I see, to bad then.

[@etr295]

If you reduce your coffee in from 20 to 15 grams you may have to change to a smaller basket. From a technical perspective using a 14/15 gram basket with a dose of coarsely grounded coffee at 6 bars could be interesting for improving water to coffee contact. Pucks with coarsely grounded coffee tend to grow big, dry and hardish saturating the space between basket and shower. I am definitely intrigued to try it!

[@CharlieLui]

Yes! I immediately thought of you when I heard the news!

[@MatthewPearson]

Yes. Thank you James. I read this whole dang paper when it can out. I finished thinking I need some third party insight on this . Thanks for the insight. Excellent video as always

[@joeydolin9948]

The other day I did a very informal experiment where we dialled in our espresso as we normally do with our normal shop parameters, and then dialled in the same coffee with the parameters suggested in the research paper. Unfortunately we did not have a refractometer :( Either way, it was very interesting to taste the differences in the shots. Along with what James said in the video, I noticed that brewing with these new parameters had more wiggle room than our normal 1:2 shots. A shot that wasn't perfectly dialled in was way more drinkable than a non dialled in shot using a 1:2 ratio. I also noticed less acidity and tartness compared to our 1:2 shots. Wow what a time to be a barista!!

[@andres.napuri]

I really appreciate that you replicate the paper for your audience. It is beautiful to notice how your curiosity drives you. Great video ☕️

[@BarryBazzawillWilliams]

Thank you. I would love to see this method in the dialing in espresso series. I have read the paper and while your explanation makes some sense as does others on HB, I would really like to see it; both with and without a refractometer. Also I am not sure if the narrower Flair Pro portafilter effects the ideal dose. I know some of the maths focused on the a 58mm coffee bed.

[@intellectualesemv]

This is interesting. Just this morning I was reading the paper that came with the Aeropress I just purchased, and their troubleshooting tips said that if it's too difficult to press, you should consider trying coarser grounds. And I thought to myself that it was weird they suggested coasrser, not linking the surface area to it. Thanks for the science reminder

[@nocturnus009]

GRADITUDE for this James, I wonder if the points you previously made about the differences between ratio & recipe apply. I hope there is a large amount of buy in to allow for a sufficiently large sample size to find that infliction point you are talking about [03:55 ]. Looking forward to the next video.

[@verryvernando3903]

HI JAMES! this sound! Is perfect 👌, keep it this way, the gain .. Usually your video have inconsistent gain, make this video your benchmark

[@cyrusfontaine2598]

The headlines were pretty comical! But the paper was fascinating. I was hoping you'd do a video on this!

[@yengsabio5315]

I love drinking coffee! I percolate for my daily dose. Watching this video & learning a lot from it makes me much more respectful of that glorious cup & enjoy every sip of it until I empty my cup! Cheers & mabuhay from tropical Philippines!

[@bassplayerrm]

In my opinion you are one of the most objective and informed influencers in the coffee/espresso field thanks for everything and how you do it, trust is everything and you have earned mine

[@matussa]

I've done this and, as you said, preparation is key and the coffee being is key. Once I've found the correct grind setting, pulled a shot with a properly arranged portafilter, I tried to eliminate static in the grounds, I sifted the coffee, tried to distribute it as well as possible, and then I pulled another shot with just coffee kinda evenly pressed, without all the I gave to the first.

[@mato9282]

Pretty stoked that my regular cafe here in Eugene, OR (Tailored Coffee) was the host for a lot of this stuff and it made it across the world and you made a video about it. I will say that the huge flaw with a lot of the studies I come across (usually beer but in this case coffee) is always this big looming missing piece of not having a trained sensory panel to correlate lab results with. It's food! Isn't that the whole point? If something doesn't taste good, not much else matters. Obviously they had some decent flavor results, and so did you, but I get frustrated by the fact that there's a lot of lab science and no sensory correlation. Thanks for taking the time to put this together!

[@frankvonsilver3601]

Hi James! Love your channel, makes me want to drink way much more coffee than whats maybe good for me. I really like this calculating about extracting and so on! What I also would like too see is some mathmatic behind a single and a double espresso? Have you done a video in that matter? Are their good numbers to read?

[@thecoffeepanda]

Just saw someone on the tube watching this video; shout out to that guy for letting me know to check my notifications.

[@rafraf3553]

Thanks so much, I am learning a lot from you

[@usafan96soren20]

You can't James...I went soft on the last Sprometheus vid. Well I wanna say it to you also. Thanks for sharing your passion with us, I'm gonna attend classes to become a barista. Thank you so much for the work you put into this for us. Thank you so much James ❤️

[@swissarmies]

I've tried this out on my Silvia/rocky setup with 15g in and 36 out it consistently takes 13-15 seconds and the espresso is much more enjoyable to me. I enjoy the looser texture and clarity and its never sour which is amazing. I would have inconsistency before where I can imagine what was being referenced towards too fine of a grind being counter to what we want. I've switched to using this technique on my daily I rather enjoy it.

[@american1911]

Which brand of 15h basket are you using?

[@HeiFuma]

Hi James, thank you so much for this Video I've been waiting for. I've tried this different way of extraction a few days ago and in my opinion everyone should give this a try. I was blown away by the increase of taste and how even the quality of extraction can be with my small home setup. This was/is my setup: Espresso machine: Bezzera Matrix MN Grinder: Baratza Sette 270Wi Coffee: IBIRACI VILLAGE Brasil Degree of roast: city I've tried 15 to 15 grams in 15 seconds, 15 to 30 in 15 seconds. I like both and I will keep those settings for longer.

[@dimitardimitrov5366]

You are amazing, one of a kind!

[@kugelrund398]

Incredible video! Couldn't it be possible that the drop in pressure and the increase in flow rate is due to the puc providing less resistance as soluble particles are extracted, rather than the uniformity of the puc changes and channeling occurs. Of course this is only the case when we are talking about a perfectly prepared puc. This is how I am interpreting this phenomenon.

[@francisrampen9099]

Thanks James for starting a really interesting discussion. I read the paper and, to me, it prompts more questions than answers - which is not a bad thing. For example, the equation they use divides ground coffee into two neat piles: boulders at >100um and fines at

[@videoguy3110]

This really reminds me a lot of something we (the coffee industry) seemed to stumble upon when EK43's were the new hot thing. At least in Melbourne Circa 2014/15, there was lots of excitement around pushing brew ratios. Recipes of 19/20 grams in, 50-70 grams out in 20 seconds. Some of the best espressos I ever had were made like this.

[@eusevis]

came back to rewatch more than a year later and now i can understand every sentence in this video!

[@Ddansk1111]

Man, great video, and appreciate the detailed analysis and opinions on what sounds like an incredibly fun scientific paper (I mean who wouldn't want to drink coffee in the name of science?). As a side note, I use a moka pot for my coffee, so i can't really do this test :(. But I have on occasion noticed uneven ground in the puck when I go to discard the left over coffee, never really thought much about it other than "I guess it's just how the extraction occurred", but now the channeling of water really answers that question!

[@TheCnoonan123]

I was about to go to sleep but now I want to pull some shots

[@polodubhthaigh9827]

Chris Noonan aye, but I want to read this paper!