Pressure profiling advice needed for a novice

Beginner and pro baristas share tips and tricks.
mdmvrockford
Posts: 233
Joined: December 10th, 2009

Postby mdmvrockford » Apr 02, 2017, 11:58 am

I have read "shadowfox" thread and "dominico" thread on this.
Pressure profiling, flow profiling, and a new rule of thirds
Pressure Profiling Techniques for Spring Levers

I still have no clue what I am doing except to tame really light roasts brewed as espresso.
Olympia Cremina piston pressure gauge unboxing
Olympia Cremina piston pressure gauge unboxing
This is despite spending way too much time (per Boss) trying to figure out this topic. I am in need of novice (high-school) level instruction please (I am a doctor and not an engineer nor professional coffee cupper) & tips for this complex (graduate school) level topic (pressure profiling).

BACKGROUND:
What I do not want to hear is: pressure profiling is a not worth measuring and just follow the flow rate and other variables. I know pressure profiling is not the end-all-be all variable. It is just another variable in the 2.8million factors in making exceptional espresso.
Espresso variables: simplicity vs complexity
I have had this discussion in person with some senior HB.com members who said basically as such (i.e. not worth measuring). I recently installed "homo barista" Olympia Express Cremina pressure piston rod with LaMarzocco gauge. I want to better use it. I am not asking for this advice for confirmation bias. Last argument for exactly measuring pressure profile: if pressure profiling was unimportant then (1) why did LM bother to have it on some of their machines (yes it is very niche portion of their customer base but it is still present)? (2) why does Vesuvius even exist and still being sold at Chris Coffee ? (3) why are lever coffee machines so popular and favored on home-barista? I know the answer to all these questions. It is a niche market and some people (novices like me) need to measure so that we can repeat same pull (my muscle memory is not as precise as senior HB.com members).
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MB
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Postby MB » Apr 04, 2017, 12:25 am

I'm not sure my response is what you are requesting, but in case you are asking for an example to start with, here's one. Having used the Espresso Forge, I find the gauge helpful to see what's going on, for repeatablility, and identification of needed grinder adjustments. The profile I use mimics a spring lever. It may not strictly apply to your Cremina due to temperature and other differences; however, for what it's worth, here is a starting point. For medium or slightly darker roasts: 10 seconds preinfusion at 2 bar (I see coffee showing at the bottom of the basket, but no actual dripping), slowly ramp up to 8 bar over 3 seconds, then slowly decline to 6 bar over 25 seconds, and finish until blonding holding at 6 bar which may not be long at all.
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mdmvrockford
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Postby mdmvrockford replying to MB » Apr 05, 2017, 12:54 am

Thank you very much. This is exactly one example (are there more?) what I am looking for.

For example: For X bean roasted Y way, I have found _______________ pressure profile works. Providing number of bar pressure and time like you did is what this novice needs.

Thanks!
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Mrboots2u
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Postby Mrboots2u » Apr 05, 2017, 3:18 am

Few questions ..
Do you enjoy the coffee that your are making ? If not what's lacking and leading to pressure profiling ?
Any pressure profile that is suggested will be but one variable of a whole load which will impact the taste - grinder - water - temp - basket. I would suggest that all of the later have more effect ( along with your brew ratio ) than small changes on pressure .

mdmvrockford
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Postby mdmvrockford replying to Mrboots2u » Apr 05, 2017, 6:37 pm

Yes, I enjoy the coffee I am currently making (effectively I only use the Cremina). One of main reasons for the "homo barista" pressure piston rod gauge was for reproducibility. The first three lines of the background section should make clear I know pressure profiling is not the end-all-be-all variable. It's just another variable among the 2.8 million variables.

I have been using 0.1 gram scale for my espresso and always calculate brew ratio since ~ 2010 (learned from this forum).

I use nothing but naked portafilters because I want to see proof of perfect distribution. I am fully aware naked portafilters and perfect looking cone with barber shop twirly thing (can't recall name) is NOT necessary for great taste or correlate to great taste. But since I make only at most 3 espressos/day, the visual aspect of being home barista is one important aspect to me but never as important as taste. "Taste is king" ; i.e. factors #one through five in order of importance for exceptional espresso is taste). Perfect looking extraction is just icing on the cake.

* Water is one gallon distilled and add in one suppository shaped tube on Third Wave Water "espresso blend."

*Temperature is monitored with "erics" therometer in location he recommends (same as recommended by most on home-barista).

*Timer (cell phone) is always used.

So as you can tell, I have been tinkering with all the other variable. Now time to open pandora's box tinker with pressure profiling (and hence the post) so I can have starting point besides the profile I describe in original post.

My reply in post#3 is what I am looking for.
Another would be: if want to bring out more ________ in an espresso THEN use _______ pressure profile.
If beans are aging, then use more _________ pressure profile.

I see your profile states you have a Vesuvius (which does pressure profiling per only Vesuvius sold by Chris Coffee in USA; are there non-pressure profiling Vesuvius?). What pressure profiles do you like for it? What pressure profile to what beans? Or if pressure profiling is really not useful then are you planning to change from this pressure profiling Vesuvius ?

Thank you in advance for your reply and time.
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Mrboots2u
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Postby Mrboots2u » Apr 06, 2017, 2:42 am

I've owned a londinium and a Vesuvius . I be sold both . I feel a little more relaxed drinking brewed coffee at home as opposed to trying to chase the espresso dragon . Re pressure profiling I ended up using flat 5-6 bar pressure predominantly , occasionally reverting to longish 2 low bar pressure then 6-7 pressure .

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dominico
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Postby dominico » Apr 06, 2017, 1:02 pm

mdmvrockford wrote:I have had this discussion in person with some senior HB.com members who said basically as such (i.e. not worth measuring).

I think its well known, and healthy for the community, that senior HB members disagree with other. My personal opinion, which is also no surprise, is that pressure profiling is worth measuring, and that having a good grasp of it will definitely improve your espresso experience. With the right skill / tools you can repeatably modulate the flavor of a cup to your preference (within the potential of the coffee of course). I often find that tweaking the pressure profile can change a good shot into a great shot. I understand that the same could be said about tweaking other variables as well, but with the exception of flow profiling, pressure profiling has the most amount of flexibility for how it is administered across different phases of the extraction.
Such is why I believe it is a useful tool, and one of my tools of choice for dialing in coffee. It may not be as useful as a tool for others whose equipment favors modifying other variables instead. Even so, modifying preinfusion time or overall shot pressure is often within the realm of most machines, and I would consider those both to be within the "pressure profiling" realm.

As far as general profile recipes go, there are a few generalizations that can be made, but there are always coffees and regions that will be exceptions.

Here are some general guidelines that I follow:
Longer preinfusion times will reduce acidity.
Higher preinfusion pressure will increase body / mouthfeel.
A declining pressure profile can increase sweetness.
As far as regions go, I have found that a sharp decline in pressure after about 2/3 the way through the shot creates a lot of sweetness for lighter roasted guats and colombias.
A slow ramp up of pressure will cause a faster overall flow (i.e. allow you to grind finer if you wish)
For dark roasts and Italian roasts I like to peak at 7 bar.
For lighter roasts I like to peak at 8 bar.

For light roasts on the Cremina I often preinfuse for 10 to 12 seconds, push on the lever and hold at 3 bar for another 3 seconds or so, then ramp to my desired max pressure. I hold that pressure until it starts dripping fast enough to get a flow, then I try to keep the flow constant at a rate where I will arrive at 3 bar when I hit the shot's target weight.
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Ellejaycafe
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Postby Ellejaycafe replying to dominico » Apr 06, 2017, 1:45 pm

I would agree with all of this. Dominic helped me out A LOT when I first got my commercial spring lever. I wouldn't say there are "specific profiles" that work every time, all the time. There simply aren't any rules when it comes to profiling.

I will say that the second stage preinfusion has been my biggest discovery and help to take flagons where I want them. So after I preinfuse, for say 10 seconds, I'll let the lever barely grab and hold for another 5-7 seconds. So essentially letting it infuse at 3-4 bar after my initial preinfusion. This helps a lot to tame, or even bring out acidity. Just have fun with it!
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mdmvrockford
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Joined: December 10th, 2009

Postby mdmvrockford » Apr 06, 2017, 10:41 pm

dominico wrote:As far as general profile recipes go, there are a few generalizations that can be made, but there are always coffees and regions that will be exceptions.

Here are some general guidelines that I follow:
Longer preinfusion times will reduce acidity.
Higher preinfusion pressure will increase body / mouthfeel.
A declining pressure profile can increase sweetness.
As far as regions go, I have found that a sharp decline in pressure after about 2/3 the way through the shot creates a lot of sweetness for lighter roasted guats and colombias.
A slow ramp up of pressure will cause a faster overall flow (i.e. allow you to grind finer if you wish)ha
For dark roasts and Italian roasts I like to peak at 7 bar.
For lighter roasts I like to peak at 8 bar.

For light roasts on the Cremina I often preinfuse for 10 to 12 seconds, push on the lever and hold at 3 bar for another 3 seconds or so, then ramp to my desired max pressure. I hold that pressure until it starts dripping fast enough to get a flow, then I try to keep the flow constant at a rate where I will arrive at 3 bar when I hit the shot's target weight.


This is exactly what this doctor ordered (looking for) :D
Do others who have experience with pressure profiling have other tips/generalization or do other agree with these generalizations/baseline suggestions?
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jwCrema
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Joined: February 2nd, 2013

Postby jwCrema » Apr 14, 2017, 11:22 pm

I started Dominico's suggestion for preinfusion after I bought the piston gauge. I feel it improved my cup.

But, I tend to look at everyone's perspective as valid to them in their process. No one is posting nonsense to throw us off. From that foundational perspective I have built my process that my wife and I find yummy every morning. While I'm sure somewhere there was a post I disagreed with, generally they're all ideas that I may or may not try.

I've pretty well settled on a 10 sec pre, with a 9 bar extraction for Redbird.

 
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