Brew pressure profiling best practices - have any emerged yet?
- pizzaman383
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Pressure profiling has been discussed in many threads here, on many blogs, etc. I've read quite a bit about pressure profiling but I don't yet have a clear picture of how pressure profiling impacts the espresso produced. With the increase in types of espresso machines that provide some type of pressure profiling it seems to have gone from a novelty to a common feature.
We know how variations in dose, grind, extraction ratio, etc. impact the brewed espresso. Have any best practices emerged describing how changes in pressure profiles change the espresso produced? Are there guidelines for what pressure profile is recommended to achiever various styles of espresso? Are we there, yet?
We know how variations in dose, grind, extraction ratio, etc. impact the brewed espresso. Have any best practices emerged describing how changes in pressure profiles change the espresso produced? Are there guidelines for what pressure profile is recommended to achiever various styles of espresso? Are we there, yet?
Curtis
LMWDP #551
“Taste every shot before adding milk!”
LMWDP #551
“Taste every shot before adding milk!”
- John P
- Posts: 138
- Joined: 18 years ago
Pressure, like temperature, should be consistent and repeatable. The definition of consistency in this instance may have more in common with repeatability than it does with "unchanging".
I do think that as many of those who believe they are on the cutting edge, really are inexperienced barista and easily impressed by new tools and gadgets. As a learning tool, understanding how different pressures extract different types of flavors in espresso is a great thing. But the reality is, while for the non-professional it may be a fun endeavor, on bar, it's a different thing. When you spend X amount of hours dialing in the "perfect" pressure profile, within short order that perfect profile has now become defunct due to the ever changing nature of the espresso. Time passes, variations in temperature and humidity occur, and you soon wonder why you messed with the stability you once had.
Just because you can doesn't mean you should.
Best practice? Find a method where you can make great espresso again, and again, and again without too much fuss.
I do think that as many of those who believe they are on the cutting edge, really are inexperienced barista and easily impressed by new tools and gadgets. As a learning tool, understanding how different pressures extract different types of flavors in espresso is a great thing. But the reality is, while for the non-professional it may be a fun endeavor, on bar, it's a different thing. When you spend X amount of hours dialing in the "perfect" pressure profile, within short order that perfect profile has now become defunct due to the ever changing nature of the espresso. Time passes, variations in temperature and humidity occur, and you soon wonder why you messed with the stability you once had.
Just because you can doesn't mean you should.
Best practice? Find a method where you can make great espresso again, and again, and again without too much fuss.
John Piquet
Salt Lake City, UT
caffedbolla.com
Salt Lake City, UT
caffedbolla.com
- bostonbuzz
- Posts: 1261
- Joined: 13 years ago
Yes, some have.
After the shot starts, anything besides maintaining the same pressure and slowly declining the pressure have no good effect. Declining may be preferred with a little-to-no preinfusion profile, but the preinfusion described below doesn't require a decline afterwards to maintain a consistent flow.
Preinfusion is where the magic happens. Infusing at a low pressure (somewhere at 3bar or lower) for different amounts of time results in noticeably different flow rates and subsequently grind requirements and tastes. Look at slayer, they do a slow ramp to 3 bars until drips form when they go to 9 bars. This preinfusion takes some time (~12s?). It requires a grind adjustment of a few notches on a mazzer grinder.
This info is from some non-scientific testing on my part, and from reading this forum for years. The long preinfusion at low pressures and subsequent grind change is obvious once you try it. I would like to get to a place where I can adjust my preinfusion instead of grind with aging coffee, and to adjust the preinfusion profile for a type of coffee.
I guess the point is that "pressure profile" is most meaningful at the preinfusion stage, and less so afterwards.
After the shot starts, anything besides maintaining the same pressure and slowly declining the pressure have no good effect. Declining may be preferred with a little-to-no preinfusion profile, but the preinfusion described below doesn't require a decline afterwards to maintain a consistent flow.
Preinfusion is where the magic happens. Infusing at a low pressure (somewhere at 3bar or lower) for different amounts of time results in noticeably different flow rates and subsequently grind requirements and tastes. Look at slayer, they do a slow ramp to 3 bars until drips form when they go to 9 bars. This preinfusion takes some time (~12s?). It requires a grind adjustment of a few notches on a mazzer grinder.
This info is from some non-scientific testing on my part, and from reading this forum for years. The long preinfusion at low pressures and subsequent grind change is obvious once you try it. I would like to get to a place where I can adjust my preinfusion instead of grind with aging coffee, and to adjust the preinfusion profile for a type of coffee.
I guess the point is that "pressure profile" is most meaningful at the preinfusion stage, and less so afterwards.
LMWDP #353
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This is my anecdotal feedback from playing with pressure profiling on a shot brewer. Every guy who grabbed it and played with it was so excited to ramp it up and down and get all sort of funky profiles going, but it was just blind guessing. After playing around, the preset profile that mimics a lever was the consensus as the best for the bean we had that day. My Strega is already very good at creating a "lever like" profile, it cooled me down on needing a pressure profile machine, at least for a little while.
LMWDP #371
- another_jim
- Team HB
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- Joined: 19 years ago
So far most people have settled on something like a lever profile, perhaps with a gradually rising pressure preinfusion rather than a low pressure one followed by a sudden transtion to fiull pressure.
However, I think this might be an artifact of the difficulty in reducing the number of possible profiles to a manageable set that can be tested. Off the cuff, I would recommend something like slow attack/fast attack -- no/some steady middle -- slow/fast decline as giving eight possible profiles to compare. This is still a lot; but manageable. This would make the conventional pump profile fast attack -- steady middle -- fast decline. A preinfusion pump profile would be slow attack -- steady middle -- fast decline. A lever profile is slow attack -- no middle -- slow decline.
However, I think this might be an artifact of the difficulty in reducing the number of possible profiles to a manageable set that can be tested. Off the cuff, I would recommend something like slow attack/fast attack -- no/some steady middle -- slow/fast decline as giving eight possible profiles to compare. This is still a lot; but manageable. This would make the conventional pump profile fast attack -- steady middle -- fast decline. A preinfusion pump profile would be slow attack -- steady middle -- fast decline. A lever profile is slow attack -- no middle -- slow decline.
Jim Schulman