Brew pressure profiling update 3 - Page 2

Beginner and pro baristas share tips and tricks for making espresso.
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another_jim
Team HB

#11: Post by another_jim »

Since you announced this, I've been trying to think of ways that would allow one to characterize more precisely how pressure variations affect taste and mouthfeel. After a lot of thought, I think the best route might be to find a coffee or roast that is undrinkable when done with a straight profile, and tasty when done with the pressure profile you like. If you can find one like that, it would be fairly clear how the profile affected the taste.
Jim Schulman

Ken Fox

#12: Post by Ken Fox » replying to another_jim »

Jim and I both have some prior experience in doing research in our earlier lives, and frequently discuss innovations and research attempts we see written about here and in other online venues. We are, in fact, planning to do an article sometime soon on the entire topic of performing coffee research at the enthusiast or small entrepreneur level.

A large corporation, like for example a drug company, can afford to hire legions of lower level researchers to do "basic science" research where interesting ideas are played with, without any specific goal, with the hope that they might stumble upon something. Even so, when a company like for example, Pfizer, has problems and they "reorganize," laying off thousands, who do you think are among the first people to be let go? Let me guess . . . . .

As individuals without unlimited time or resources, we are forced to be VERY focused in our work, or, our work will likely come to nothing.

If you look at the stuff that Jim and I have written up over the last few years, the "success" that it has achieved has been due primarily to choosing relatively small questions that can be answered in straightforward ways. I'd of course like to think that we are genuises and that this has allowed us to study rotary pumps and vibe pumps and preinfusion and freezing -- but the truth is that we asked simple questions and studied them in very simple ways. For example, if you take the freezing study, it was designed to prove or disprove the notion that freezing ruins coffee and or does not preserve it. Testing that is a very straightforward proposition, as opposed to testing what impact altering all aspects of the extraction pressure curve might do.

If you take temperature stability, another topic that has been debated A LOT, it has now been achieved to one degree or another on a number of different machines, either factory (Aurelia; maybe GS3) or with mods (Greg's modified Linea, my Juniors), yet no one has tested in a convincing way what impact the shape of the temperature profile has on espresso shot taste, or whether the whole exercise has much merit beyond knowing one has less variable brew temperatures.

As to pressure, I would submit that what you are trying to test, Greg, is an order of magnitude, maybe two, more complex, and it suffers from the problems in tasting temperature cure importance, in addition. As a result, unless your work becomes VERY focused, I think it is going to be very hard for you to conclude much of anything.

Adjusting and calibrating things like temperature and pressure are interesting, and they should be important, however they are coming at espresso making much in the way that basic science drug research comes at solving medical problems. You don't have enough time, enough lives, enough other people to do this stuff with, enough physical and monetary resources, to do enough testing with the variables you are presenting yourself with to have much hope of getting anywhere other than to say, "I changed this and that and the other thing and so and so was over and we both thought the shots were better." I hope I am wrong, but I don't see that sort of work going very far.

My suggestion would be to start with some very specific issue in espresso extraction, a problem, something you think can be fixed with one significant change in pressure profiling, then test that. I think this latter approach has the chance of bearing some fruit.

Good luck.

ken
What, me worry?

Alfred E. Neuman, 1955

SL28ave

#13: Post by SL28ave »

I think what I got out of my visit with Greg was that a curved profile was better than flat, at least with the given beans, equipment and technique. We tasted using a flat profile, where I think the pump pressure was constant, which to some extent - strength irrelevent - left an acridic aftertaste. The curved profile didn't have this aftertaste.
"Few, but ripe." -Carl Friedrich Gauss

gscace (original poster)

#14: Post by gscace (original poster) »

Ken Fox wrote:
Jim and I both have some prior experience in doing research in our earlier lives, and frequently discuss innovations and research attempts we see written about here and in other online venues. We are, in fact, planning to do an article sometime soon on the entire topic of performing coffee research at the enthusiast or small entrepreneur level.

A large corporation, like for example a drug company, can afford to hire legions of lower level researchers to do "basic science" research where interesting ideas are played with, without any specific goal, with the hope that they might stumble upon something. Even so, when a company like for example, Pfizer, has problems and they "reorganize," laying off thousands, who do you think are among the first people to be let go? Let me guess . . . . .

As individuals without unlimited time or resources, we are forced to be VERY focused in our work, or, our work will likely come to nothing.

If you look at the stuff that Jim and I have written up over the last few years, the "success" that it has achieved has been due primarily to choosing relatively small questions that can be answered in straightforward ways. I'd of course like to think that we are genuises and that this has allowed us to study rotary pumps and vibe pumps and preinfusion and freezing -- but the truth is that we asked simple questions and studied them in very simple ways. For example, if you take the freezing study, it was designed to prove or disprove the notion that freezing ruins coffee and or does not preserve it. Testing that is a very straightforward proposition, as opposed to testing what impact altering all aspects of the extraction pressure curve might do.

If you take temperature stability, another topic that has been debated A LOT, it has now been achieved to one degree or another on a number of different machines, either factory (Aurelia; maybe GS3) or with mods (Greg's modified Linea, my Juniors), yet no one has tested in a convincing way what impact the shape of the temperature profile has on espresso shot taste, or whether the whole exercise has much merit beyond knowing one has less variable brew temperatures.

As to pressure, I would submit that what you are trying to test, Greg, is an order of magnitude, maybe two, more complex, and it suffers from the problems in tasting temperature cure importance, in addition. As a result, unless your work becomes VERY focused, I think it is going to be very hard for you to conclude much of anything.

Adjusting and calibrating things like temperature and pressure are interesting, and they should be important, however they are coming at espresso making much in the way that basic science drug research comes at solving medical problems. You don't have enough time, enough lives, enough other people to do this stuff with, enough physical and monetary resources, to do enough testing with the variables you are presenting yourself with to have much hope of getting anywhere other than to say, "I changed this and that and the other thing and so and so was over and we both thought the shots were better." I hope I am wrong, but I don't see that sort of work going very far.

My suggestion would be to start with some very specific issue in espresso extraction, a problem, something you think can be fixed with one significant change in pressure profiling, then test that. I think this latter approach has the chance of bearing some fruit.

Good luck.

ken
Well Ken I have to say that it's tough to prove almost anything in coffee it seems. I mentioned Jim and your work on the freezing thing to a coffee pro and got an answer that it was somewhat arrogant to say that across the board there would be no affect on coffee taste from freezing, and that the results would be more believable if someone whose palate had very proven credentials had done the blind tasting. So you see how it goes. If you're an amateur researcher in coffee you're always gonna have folks who try to poke holes in your work. It's prolly best to have a thick skin about it, because you can do the work, see a gain and then rant until your blue in the face and some folks won't get it. I'm cool with that.

Take temperature for instance, since you brought it up. We still don't know if a flat line profile is the best one. One can theorize convincingly that it ain't by invoking just a bit of heat transfer theory, but we aren't gonna know until someone builds a test machine that allows reproducible testing. And then there are still gonna be people that won't believe what you come up with. I think enough noise has been made about it so that we at least got folks building machines that have the ability to reproduce the same thing two time in a row. That at least makes it so that things are more consistent.

I suspect the same thing is true of pressure. We haven't investigated it much. Folks who have fooled with it see something to it, and people who have come to my house have seen something from it, although my attempt at blind testing failed miserably because my methodology was pretty piss poor. At any rate, if enough people see some benefit to it, and a couple of forward-thinking machine manufacturers investigate it, maybe we'll see it in machines of the future.

Regarding your last paragraph, I think I'm learning what can be improved by the profiling scheme. When I get more time, I'll see if I can't make a test that satisfies a fraction of the folks who care.

-Greg

Ken Fox

#15: Post by Ken Fox » replying to gscace »

Hi Greg,

Anyone reading the "freezing article" carefully would see that there were enough qualifications given on the conclusions to fill a couple of warehouses. It would not surprise me in the least that if you assembled 100 of the best coffee palates out there, and did 5000 paired shots, under somewhat different conditions, that a difference would have been found between never frozen and previously frozen "fresh" coffee. Finding THAT SORT of a difference was never the intent of the study. Most of us are not blessed with one of the best 100 coffee palates, and most of us don't live across the street from one of the world's best artisan roasters, offering up absolutely fresh coffee anytime that we would like to purchase it.

Coffee on a home enthusiast level (for most of us) is all about compromises. It is like the decision I made a few years back that there were damn few wines worth $100, at least not to me. So I'm drinking Savigny les Beaune and not La Tache. So what? My neighbors are drinking Gallo Hearty Burgundy, and I'm happy with being up near the top if not AT the top.

If you can limit what you are studying to your 1 or 2 best ideas, you have a real chance of finding something, that will be not only meaningful but useful to the large group of us who watch your every move. If you find something useful in the first study, then there will be time for another, and so forth.

Best,

ken
What, me worry?

Alfred E. Neuman, 1955

SL28ave

#16: Post by SL28ave »

Ken Fox wrote:La Tache
*drool*, will I ever the chance? I do very often wonder what kind of shot it would taste like; probably doesn't exist yet... Jim, I just bought an intense CnDP Reserve Sixtine if we can manage to fit it in the midst of all the coffee we'll be drinking later this month :wink:
"Few, but ripe." -Carl Friedrich Gauss

Ken Fox

#17: Post by Ken Fox » replying to SL28ave »

Hi Peter,

I've been fortunate enough to have a wine cellar, or at least some place I could cellar wines in good conditions, for around 25 years. There were times during this period when wines now considered unobtainable were available for purchase at very reasonable prices. I still have a few bottles of Pichon Lalande with $13.95 price stickers on them, and remember buying first growth Bordeaux for around $50. I also remember buying the "mixed case" Domaine de la Romanee Conti for about a thousand dollars, which includes such things as a bottle of Romanee Conti which must sell, these days, for more than the price I paid for the entire case.

The bottom line on all of this, if you buy this stuff and age it under good conditions is that it is a pure crap shoot. Sure, I've had the odd bottle that was very expensive way back when and would blow your socks off now, but the truth is that most of these vaunted bottles turn out to be huge disappointments after you have aged them and waited for them over a decade or two or three. They simply cannot live up to their hype.

Nowadays, I'd much rather buy some under-the-radar bottle for $15 or $20 or $25 and lose it in my cellar and stumble back onto it 10 years later and find that it hugely exceeds my expectations. Now that is a great experience. To have paid $20 for something and to open it 10 years later and have it taste as good as La Tache.

It has happened to me, and it has happened more often than for those expensive bottles to meet the expectations that one could reasonably have for them.

So, I've just stopped buying the pricey ones.

ken
What, me worry?

Alfred E. Neuman, 1955

SL28ave

#18: Post by SL28ave »

Thanks, Ken. I will hold your word dear.

But when I see for the first time "ginger" in a wine description, from some Australian retailer-fanatic, I still wanna give this wine a go: "2004 La Tache: Floral, ginger, anise and red currents on the nose. In the mouth it is a silk cloth with floral print. Terrific shape, good volume and great cut on the finish.".... like a silk cloth with floral print! Wha? If I ever have the chance for a teaspoon of this wine, hopefully it'll be at the most delicate and perceptive moment of my life. :cry:

Sorry for the drift, Mr Scace. Back on topic.
"Few, but ripe." -Carl Friedrich Gauss

Ken Fox

#19: Post by Ken Fox » replying to SL28ave »

Peter,

The problem is that this guy's "ginger" might just be your "soiled undergarments."

ken
p.s. not kidding
What, me worry?

Alfred E. Neuman, 1955

SL28ave

#20: Post by SL28ave » replying to Ken Fox »

I wanted to take your comment about my soiled undergarments smelling like ginger as a compliment, but I didn't even soil my undergarments as a baby :lol:. I think I get what you're saying, though... Good thing I had already tasted the Reserve Sixtine before deciding to serve it. So, we'll see :)
"Few, but ripe." -Carl Friedrich Gauss