5 bar espresso --- WHAT THE H.... - Page 2

[Jeff]

Light-roast espresso is a different drink. There aren't many discussions here about either top roasters in the category or approaches for extraction. Long preinfusion and a super-fine grind are one approach. The other approaches and apparently even gear get shot down by the traditionalists. Extraction techniques and gear for light-roast espresso can be highly revealing of green and roast defects. Run a comfort espresso on gear and techniques selected for light-roast espresso and you'll likely end up with a bitter mess.

[mrgnomer]

I believe light roasts just into 1st crack are aroma denser than 2nd crack dark roasts. Dark 2nd crack roasts are less dense. Dark 2nd crack roasts are more easily over extracted and benefit from coarser grinds, lower dose, lower temperature and shorter extraction time.

With more complex aromas still remaining in the light roasts there's more to extract. Light roasts benefit from greater and longer extraction to pull the aromas out of them. Finer grinding, higher dose, higher temperature and longer extraction times work for light roasts.

With a new lever machine I'm experimenting with doses, grinds, temperatures, preinfusion times and pressures, extraction times, volumes and pressures following the light roast/dark roast extraction profile standards. The extractions have good character and flavour.

[PIXIllate]

Light-roast espresso is a different drink. There aren't many discussions here about either top roasters in the category or approaches for extraction. Long preinfusion and a super-fine grind are one approach. The other approaches and apparently even gear get shot down by the traditionalists. Extraction techniques and gear for light-roast espresso can be highly revealing of green and roast defects. Run a comfort espresso on gear and techniques selected for light-roast espresso and you'll likely end up with a bitter mess.

Care to elaborate?

[Jeff]

I guess I can't answer "no", eh?

This is one of those topics that will surely bring down the wrath of the traditionalists here. So I'll start by saying that if you're buying roasted coffee for home in 5# bags, you can skip the rest of this. If your coffee is roasted to anywhere near second crack, skip this. If you think that crema is a necessary part of good espresso, skip this. If you think contemporary roasts are stupidly underdeveloped, or that you can roast it yourself better, skip this. If you're with the Certified Italian Espresso police, "nothing to see here, move along".

First, pressure, which is something to think about for any roast level, with any grinder.

8-9 bars or so is where strange things start happening in the puck. The puck starts resisting more in a way that the flow goes down with more pressure. One reason for dropping the pressure is to stay out of this region. Lever machines have been in the 4-6 bar range for decades. Many believe that the kind of flow you get with a puck under "secondary compression" is poorer for extraction than lower-pressure flow. Now you've got a second reason. There is evidence from controlled experiments to support both of these hypothesis.

Another reason to go with lower pressures is harder to prove experimentally. Or maybe it is just that nobody wants to pull scores of shots that have imperfect puck prep. The thinking is that to achieve a given flow rate that the higher the pressure, the higher the puck resistance needs to be. Higher puck resistance under higher pressure seems to be a doubly bad situation for encouraging channeling. Since I can't really quantify it, call it half a reason, for 2 1/2 reasons to drop your brew pressure.

So, step one, drop your brew pressure, whether you're pulling medium-dark, medium, medium-light, light, or beans barely waved over a candle flame.

I don't care that some son of an Italian espresso manufacturer says that 11 bar pump pressure is right. Just try it. Go at least 2 bar lower than what you're running right now and at least down to 7 bar. You will have to dial in again. Try it for a week or two. Note both the taste as well as the fraction of your shots that you consider unexpectedly poor. If you don't like the results, go back a notch, or even back where you were. Double check that you weren't fooling yourself and that it actually was better at lower pressures and that it isn't as good now that you're back at higher pressures.

Working with Lighter Roasts

If you try to pull a "textbook" 1:2 shot in 25 seconds with light roasts, it will probably be more acidic than it could be. Coffee is almost always acidic. Older styles roasted darker to help reduce acidity in the resulting coffee. Some people just don't like acidic coffee and probably never will. It's a Coke/Pepsi thing. Me? The store was out of Limonata today, so I'm drinking Pompelmo (grapefruit) tonight. Very refreshing in its brightness.

With a quality, lighter roasted bean you can get a good balance between the light flavors, the acidity presents as "brightness", and there is a sweetness. To get that balance, you generally need to improve the extraction. One way to do this is to grind finer, revealing more surface area per mass of grind. Finer grind, you increase puck resistance, the puck blows through under pressure (see previous section). So, let's soak it for a long time. Now the grinds seem to not blow out as much and the puck doesn't crumble into bits so quickly. This is one way to deal with it, especially if you're still pulling at 9 bar or so. Another way is to increase the temperature, something that also comes from traditional espresso technique.

You can also increase the flow rate (more energy), increase the amount of water, or both. These ideas seem to scare or even threaten traditionalists. Cries of "that shot looks terrible, you're channeling", "it's not espresso at high ratios" or "there's no crema" abound. Fine, it's not your preference in espresso. Pull 1:2.5, 1:3, or even higher with minimal soak, all in the same time or even less than a classic shot. 15 seconds or less from pump on for some burr sets is not unusual. The soak is more of a pause as there really isn't a "first drops" point, the flow just starts. This is something people are doing on manual levers and spring levers, and conventional pump machines, not just flow-managed units. Tuning to taste is primarily by ratio on this kind of shot. I may come back and see if a tighter grind improves things further, before getting into unpleasant astringency.

One reason a tiny number of burrs are interesting to light-roast enthusiasts is that they seem to extract more from the beans and more quickly. The SSP 98 HUs and 64 MPs are two of the most notable of these. With these burrs and high-quality coffee, the ratio can be tightened up and a roughly 1:2 shot pulled in around 15 seconds, from pump on.

Here's one of Joe D's shots, as an example.

[espressotime]

Best shots I've made with lower pressure.I believe to me optimum is 6-7 bars.

[chockfullofbutts (original poster)]

Thanks for the answers. I had no idea this was such a common practice.

He told me their philosophy is 'grind as fine as possible and use more water'. If anyone in NYC hasn't been there I can't recommend it enough. I've had plenty of coffee in my life and feel like they are on another level.

Next question, in light of this information, is it worth upgrading my machine to a flow control lever?

[mrgnomer]

An extraction factor that's interesting is grind fines. If I understand right it's those finer grinds you get from grinders and burrs that are distributed in your dose and drop to the bottom of the basket when you tap for distribution or extract with little or no preinfusion. They collect at the bottom of the basket during extraction and affect flow rate.

My grinders have always been middle of the road prosumer grinders which I've never checked for burr alignment or switched stock burrs out to higher grade burrs. I chase extraction control by messing with the other parameters. I've never really thought about what grind consistency is doing to affect extraction. What I have noticed with a lever machine is longer controlled preinfusions and lower extraction pressures that ramp down produce a shot that has more notes and character than the stock plumbed in, rotary pump, 8.5 bar e61 HX I was using for years especially with really light roasts. Part of that might be fines not migrating as easily with longer preinfusion to affect extraction flow/rates.

[mathof]

Working with Lighter Roasts
You can also increase the flow rate (more energy), increase the amount of water, or both. These ideas seem to scare or even threaten traditionalists. Cries of "that shot looks terrible, you're channeling", "it's not espresso at high ratios" or "there's no crema" abound. Fine, it's not your preference in espresso. Pull 1:2.5, 1:3, or even higher with minimal soak, all in the same time or even less than a classic shot. 15 seconds or less from pump on for some burr sets is not unusual. The soak is more of a pause as there really isn't a "first drops" point, the flow just starts. This is something people are doing on manual levers and spring levers, and conventional pump machines, not just flow-managed units. Tuning to taste is primarily by ratio on this kind of shot. I may come back and see if a tighter grind improves things further, before getting into unpleasant astringency.

One reason a tiny number of burrs are interesting to light-roast enthusiasts is that they seem to extract more from the beans and more quickly. The SSP 98 HUs and 64 MPs are two of the most notable of these. With these burrs and high-quality coffee, the ratio can be tightened up and a roughly 1:2 shot pulled in around 15 seconds, from pump on.

The above is a good description of what I've experienced since mounting Kafatek's Shuriken Light-Medium burrs on my Monolith Flat. I've been wondering how it is that I can get quite high extraction yields from ultra-light beans with shots that pull in around 15 seconds. The extra energy provided by faster flow must be (part of) the explanation. Thanks.

[jpender]

You can also increase the flow rate (more energy), increase the amount of water, or both.

What does that mean, "more energy"?

[baldheadracing]

I guess I can't answer "no", eh?

I see what you did there, eh?

Thanks for the answers. I had no idea this was such a common practice.

It's common within an uncommon group. That group is probably overrepresented among regular posters of Home-Barista. Most people making espresso at home fall into the "stop reading here" groups that Jeff identified.

As for upgrading, be very careful with your choices, as most equipment is tailored towards those "stop reading here" groups.