Pressure profiling

[Zaneus]

Re: Pressure profiling

I find lowering the end shot pressure down to around 7.5 bar to give a more consistent espresso. Ie less likely to blonde early due to an average dose and/or distribution. On our hydra i have the ramp down set to the last 7% of the shot. Its not enough to really effect the flavour.

I also have a 7 second preinfusion at 7 seconds and a ramp up to 7bar for a further 3 seconds (though i dont really believe thats necessary) then full pressure. Preinfusion helps with consistency as well but i notice a decrease in body.

[muppet_man67]

I kind of agree with most things bosco_lever says except for this.

If the beans are new wave, lightly tanned; and your goal is to produce espresso around the citrus flavour wheel, then you will have to use those mega deep baskets and overdose like crazy. With the gen 2 you should be able to extract a 5ml ristretto that hits the spot.

James Hoffman talks about it here. A love/hate relationship with espresso « jimseven

[potentialfig]

Good coffee quickly is exactly what I have set up, and refined. And exactly the reason why I have waited before experimenting with this sucker. I have set up a second grinder and isolate one group when I play. I'm using the 4 stage system with stage 1 @4 bar, stage 2@ 7, stage 3 @9, and a ramp down @ 7.
I'm playing with the timing of of these stages, keeping dosage and temperature level to remove some of the variables.
And yeah, I have the freedom to change the flavour and style of our espresso as I desire.

[Bosco_Lever]

One of the old guys (mid 60's) who lives at the end of my street, has a Bentley. I have seen him hand the keys to his latest acquisition (a pretty lady half his age), and am positive he said "have fun". I am also positive there would be strings attached.
Not sure about your situation though.

Anyway, when it comes to pressure profiling, I use coffee roasted to at least second crack ( or on the cusp), pull down my lever and wait 6-10 seconds. The exact pre-infusion time is dependent upon many factors (freshness of the coffee, barometric pressure, country of origin, roast profile, phase of the moon..... but more importantly, whether or not I get distracted by the blonde sunbathing across the river). I raise the lever and let it do its magic, the old fashioned way. My simple, non luxurious lever, produces damn good coffee, so my "never ending search" finished a long time ago. The aim is to learn how to use your tool properly. There are many secret "lever pulls" and techniques, but you have to be a member of the "coffeemasons" before the dark arts are revealed.

As to your toy, the variables start with your coffee. Talk to your roaster.
If the beans are new wave, lightly tanned; and your goal is to produce espresso around the citrus flavour wheel, then you will have to use those mega deep baskets and overdose like crazy. With the gen 2 you should be able to extract a 5ml ristretto that hits the spot.

Using an expensive "designer" machine to replicate "pressure profiles" on lever machines that are half the price, and more reliable, does not make sense to me.
If you have to constantly change settings, profiles, push two buttons while standing on one leg etc,etc to produce one cup of coffee, you will send the establishment broke. Get help from your roaster, they should know their product. The goal is to produce lots of cups of good coffee quickly, so the owner can actually earn some money. Unless your situation is like my example above.............

[muppet_man67]

I've been working on a Strada since the start of the year. With so many variable at your fingertips it is a minefield over and above basic espresso extraction, results can be hard to quantify. With that said, I have learnt more about espresso in the last 4 months then I had in the last 4 years.

Some things that seem to be working for us.

Full puck saturation pre-infusion, you'll need a naked portafilter, pre-infuse until coffee beads on the bottom of the basket. 3-4 bar pressure seems about right otherwise it takes too long, I'm finding about 6-8 seconds. This will have a big effect on the grind you use allowing a much finer grind and helping to increase your extraction. This is also the part of the shot that gives you enhanced body over non-profiled machines.

Higher pressures bring out more brightness, Lower pressures dig into the coffee a bit more sometimes finding good things sometimes not so good and sometimes both. I haven't found much benefit brewing outside of 9.5 to 8 bar range.

In regard to ramping up/ramping down or intra shot curves I still haven't really formed any conclusions. I don't think mimicking a lever style tail of is what you want to do.

Levers have a temperature profile that the pressure roughly matches. Slower flow/lower pressure increases extration, as you have a temperature profile that is extremely flat, any decline in pressure should be moderated. I'm not convinced declining presssure/increased contact time is something you want at the end of a shot when its mainly bitters left in the puck.

If you are going to have a pressure ramp down my feeling is that at ought to be fairly subtle, ie occur within a 1.5 bar range and its purpose is to moderate the way flow normally increases though a shot.

Planning on running some tests in the next couple of weeks to really get on top of those things. I want to set up a test where Ill find a flat pressure that works best for the coffee. Ill then see if I can find a reducing profile that tastes better.

Every action has an opposite reaction that you'll need to compensate for. If the espresso is already dialled in and tasting good, any adjustments you make with pressure will need to be offset with something else, be it grind, extraction time, or temperature, thats where it gets really tricky to manage without wasting too much coffee and or burning out your taste buds.

Good luck. Look forward to hearing your results.

[potentialfig]

Ok guys first post here so be gentle.

I have just started a new job in a brand new cafe with a brand New synesso hydra gen 2.
This thing is luxurious. It's like someone handed me the keys to a Bentley and just said 'have fun'.
Anyway after a week of just loving using this beastie, I have started playing with pressure profiling, just pure experimentation, that never ending search for a better cup. So far I have had some aweful results and some unbelievable results.
What I am asking of you guys is for any advice, hints, tips, profiles, settings to try. Any help would be greatly appreciated.