Pressure- which should I pay attention to?

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by Vindibona1 »

I know that 9 bars seems to be the defacto pressure setting for opv setting. I adjusted the general pressure with a blank basket installed to be 9bar. But when brewing with the Lelit flow control paddle wide open, with The "open" setting allowing 5.6mL/sec flow. When brewing, the pressure gauge on the nose of the E61 only went up to 8 bar.

Is 8 bar brew pressure standard or acceptable? If I need to increase the overall pressure I can do that. Or, if more water flow debit is required I can increase the flow by resetting the paddle. I'm getting 25-31 second pulls depending if I load 18 or 19gs of grinds.

I guess my question derives from only having 8 bar pressure on the E61's "nose" gauge during brewing wondering if an adjustment is needed somewhere to bring that up to 9 bar? Or, is that pressure standard or usual while the blank's reading at 9 bar?

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#2: Post by Jeff »

What matters to the result in the cup is the pressure in the basket.

The whole 11-bar, 9-bar, 8-bar thing seems to be a hold over from the early days of pump-driven machines and Italian espresso. There's some hand-wavy reasons why 9-bar pump pressure might have been picked back then. My favorite of them is that around 8-9 bar the puck starts to behave strangely, sometimes to the point of having less flow with more pressure. 9 bar might have been the fastest that they could crank out the singles and doubles of the day. I have no idea if that was how they decided on 9-bar pressure at the pump.

Due to restrictions in the flow path between the pump and the basket, the basket pressure at reasonable extraction rates is probably about 1 bar lower than at the pump (without any flow-knob set to restrict flow significantly).

The lever machines seems to run at a somewhat lower pressure. Some consider 4-6 bar in the basket to be very reasonable pressures. The DE1 people writing about extracting light-roast espresso are tending to the 4-6 bar range as well.

My own experience with an E61 and typically medium-ish coffees is that I found over 8.5 bar blind pressure to be generally less enjoyable in the cup than around 8 bar. With the DE1 and light-ish coffees I found that peaks over 8 bar tended to taste flat or cardboardy compared to those that stayed below 8 bar (the DE1 measures effectively in the basket, not at the pump). Staying around the 4-6 bar range, for my coffees, grinder, and extraction profiles tends to give me a balance that i enjoy. If you're working with comfort espresso, your results may be very different.

Vindibona1 (original poster)

#3: Post by Vindibona1 (original poster) »

What exactly is "comfort espresso"? I've been using La Colombe Nizza medium roast for a few years, having discovered it at a coffee bar in Florida and one or two othe places and stayed with it for consistency and I could get it a few days off the roaster. Having a subscription where I get beans on a weekly basis seems to keep everything consistent and relatively fresh.

When I had a Saeco Sirena we'd buy Costco Starbucks French roast and grind it in a modded Cuisinart grinder. Crazy as it sounds that combination was pretty good and consistent. So I never did experiment with a lot of different beans.

So if I get what you're saying, seeing eight bars on the nose gauge isn't necessarily a bad thing. However I think the biggest problem that I'm facing is that I really don't know what a great espresso tastes like. At this point my taste buds pretty much register drinkable or undrinkable with perhaps a few nuances in between. I have a better time judging good French press in and can easily tell when I've hit it on the nose or missed the mark. But I do love the challenge of espresso and I'm enjoying my new machine immensely.

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#4: Post by Jeff »

I consider "comfort espresso" to be the classic, usually medium or darker roasts, usually blends, generally pulled at around 1:2 or shorter. The flavor profiles tend to be generally "chocolate and nuts", perhaps with a hint of some darker fruit, like cherry or blueberry. Whether La Colombe Nizza is actually a medium roast or not, "Milk Chocolate, Nuts, Brownie" puts it squarely in the "comfort espresso" category for me.

There's a wide range of coffees that fit into that category. If I were to guess, despite what you read here, it is probably still the most popular style of espresso, by far. One way to start to get to know what "good" espresso is to try some at some of the better cafes in your area (assuming that the COVID concerns are within your own tolerance levels). Not all of it will be "good", but you can start to taste the range of possibilities. If you search here on "Chicago cafe" (or wherever you might be), you can get some other members' opinions on some that might be worth trying.

Once you've got an idea of what the possibilities are, you could try different roasters' offerings. Everyone has different opinions, so be aware that just because Person A loves it, you may hate it. Some of the general characteristic to keep track of in understanding your own preferences include:

* Roast level -- you have to judge this yourself, as there is no accepted standard for labeling something "medium" -- surface oil droplets or patches is one "line" that is pretty obvious when you get the bag, or sometimes see a photo on a website

* Robusta in the blend or not -- robusta tends to add a lot of body and crema to a blend. It also has a slightly different flavor profile than arabica, the "other" common coffee

* General areas that the coffee comes from (Central and South American coffees often taste very different than African coffees or Asia/Pacific coffees)

* "Natural" vs. washed processing (Natural isn't somehow safer, it is just that the beans ferment a bit in the cherry, rather than having the pulp removed earlier in the process)

The three-word descriptions are often a lot of marketing fluff, even from some high-end roasters. I think it is reasonable to expect something that describes "baker's chocolate" "roasted walnuts" and "tobacco" to be a rather darkly roasted offering. Something that is describing "lime", "grapefruit", or other acidic citrus fruits as the predominant flavor is probably not going to have the rich chocolate and nuts profile that a comfort espresso usually has.


#5: Post by emradguy »

E61 machines tend to show a slightly higher (~.5 - 1 bar) pressure using a blind basket versus a regular basket filled with ground coffee. To me, if you pretty much like the flavor profile, but want a smoother mouthfeel and softer flavor notes (I think of it as a "less aggressive" shot), dropping your pump pressure will help, but it's not going to fix a shot that isn't dialed in well already. At 10 bar or higher, you are likely to start experiencing difficulties getting even extractions, perhaps even with obviously visible channeling if you use a naked pf. I kept my Duetto set to 9 bar (blind insert), and my shots peaked around 8, slightly higher, but less than 8.5. If you still feel the need to lower your pump pressure, I'd drop it in 1/2 to one full bar increments.

Also, FWIW, I think of "comfort blends/shots" similar to how Jeff described them.