How do you explore the extraction space?

Beginner or pro barista, all are invited to share.
DavidMLewis
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Postby DavidMLewis » Nov 18, 2005, 7:22 pm

This is primarily a question for Chris Tacy, although of course anybody's welcome to answer. In various reviews, you speak of varying the basket size, dose, temperature, drink size, and extraction time. Exploring this space with a new coffee seems like a hugely daunting task, particularly for those of us who home-roast and therefore may have at most half a pound of a given blend, with no assurance that the next roast of the same coffee will be exactly the same. Do you have any rules that help you do it? I'm deliberately leaving this open-ended, although I have some vague, weak ideas. Thanks in advance for the help.

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David

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malachi
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Postby malachi » Nov 18, 2005, 7:58 pm

Wow.

It's a big topic - and a bit daunting.

To be honest, it's largely trial and error leading to some vague understandings of general rules. I wish I were better at it or it were more scientific.

I tend to follow a pretty clear process and will happily describe this if it will help.

If I have a new coffee I tend to always start with the LM ridged double basket and a target extraction volume of between 1.75 and 2.0 oz.

First I'll establish a brew temp starting point.
I'll evaluate the coffee for two characteristics. First - roast degree and second - bean composition.
With the former, I tend to make some quick rough decisions. If the roast is light, I tend to start with a baseline temp of 202F. If medium, I will stick with 200F. If dark, I'll drop it down to 197F.
Now... I'll also adjust this based on the bean composition. If, for example, I'm working with high-grown washed arabica I'm going to reduce the brew temp. If I'm working with aged or monsooned coffees I will up the brew temp (both from the baseline above).
So a light roasted coffee with monsooned beans will move up to 203F as a starting point.

Once I have a temp starting point I'll establish a dose starting point.
For this I'll look at two aspects - the bean composition again and then the "signature taste."
If the coffee has a lot of naturals or pulped naturals I'll go with a lighter dose. If the coffee is mostly high-grown arabica I'll up the dose.
So, for example, with the Terroir Daterra Reserve I'd go with a 17.5 gram dose. But with the Stumptown Hairbender I'd go with a 20 gram dose.
The "signature taste" is a harder one and requires some knowledge of the roaster. Is the person roasting this coffee a fan of low acidity espresso? Are they a "chocolate bomb" aficionado? If you know what they like out of their espresso you can do minor adjustments to your dose. So, for example, based on this I would actually drop the Terroir Daterra down to a 17 gram dose but would up the Stumptown Hairbender to a 20.5 gram dose.

Once I've got temp and dose I'll start experimenting.
I always start by re-evaluating temp. So I'll pull a shot and evaluate it for brew temp. Is it alkaloid? Is it thin? Is it sour? Astringent? Based on the taste, I will alter the temp by small degrees to find the sweet spot.

Once I've found what I feel is the brew temp sweet spot, I'll start working on dose.
The way I tend to do this is focus on two things. First - clarity of flavour and second - roundness and balance.
If the cup is "muddied" I'll reduce the dose. If the cup isn't fully developed and sweet and rich I'll up the dose.

With many coffees this will get me to the point where I'll have a cup profile I really like.
But there are exceptions. There are times when I won't be able to get to where I want to be with just these factors.
It's usually only at this point that I start looking at changes to extraction volume and basket size.

For example, I've found that some lighter roasted delicate coffees tend to end up poorly developed no matter what I do - especially when they are pulped naturals. But if I then swap to a triple basket and deliberately down-dose (19 grams) I "open up" the coffee and it becomes more defined and clear. Or with monsooned coffee I find that the only way I can get the desired sweetness without getting a "wet cardboard" aftertaste is by going with a triple basket, normal dose and then pulling a ristretto shot.

A lot of the time I'll find a "sweet spot" that I like but then start wondering about what a coffee would taste like when pulled differently.


To be honest... I'm incredibly lucky. Most of the coffee I experiment with is free to me. If I were roasting my own, especially in small batches, I don't know if my approach would work at all. And if I were paying retail... I don't know if I could force myself to throw away so much money.


Ummm... was that at all helpful or clear?
"Taste is the only morality." -- John Ruskin

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another_jim
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Postby another_jim » Nov 18, 2005, 9:30 pm

I follow a simpler process, since I don't experiment with dosing (I'll have to now), but just with temperature and ristretto/normale.

If I'm tasting something bright, like an SO, I start with a high temp ristretto, since I find this the most "comfort food" shot. Generally these come out sweet and undeveloped. I use the Faema basets for these, since I find the LM baskets don't work well for ristrettos (the flow is too even, the Faemas start slow and black, and get faster and lighter, so are easier to use for ristrettos). I generally move to lower temperatures and longer shots at the same time. If the shots aren't sweet enough but bitter, I'll stay ristretto while dropping temp. If I've decided on longer shots, I go to the LM double basket, since these have a clearer flavor and a more uniform extraction for anything near normal size/dose. I don't much like the triple, since the proper dose overflows my 2 ounce cups, and for my taste, they really suck on ristretto shots. Certainly, if ever experiment with lowered doses, I'd certainly use the LM basket, since the faemas seem to work best when overstuffed (there's a smaller 12 gram double, which I haven't quit figured out yet.)

Much of this is based on my habits, what I'm comfortable with, etc. YMMV. It's best to experiment with a fairly mild washed coffee with a bit of complexity both top and bottom, I'd recommend an east african, or oddballs like the blue lintong. These are more consistent pull to pull -- a harar or yemen never tastes the same, even if the shots are identical. Burn through a pound of the coffee trying various temperatures, doses and grinds. That will do it.

I find I usually know how I want to adjust the next shot when I taste this one; but I'm not entirely sure if I've described all the factors -- I tried in the espresso guide -- but by now it's pretty automatic.

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cannonfodder
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Postby cannonfodder » Nov 18, 2005, 11:58 pm

You know, I have been trying to absorb everything I can over the past year of my espresso journey. I have read, tried, gotten Zen with and gone uber-techno-geek with equipment and beans. But these two posts are two of the best I have read.

I really wish I could spend a couple of leisure days with a professional barista just having a leisurely discussion about the tricks of the trade and sampling espressos prepared in different ways. I often wonder if those few of you that live close to Chris, Dan, Jim, Terry, Mark, (and the list goes on) realize how lucky you actually are. To be able to drive over to Chris's house and have shots from the mother of all home machines or a jam session at Counter Culture, maybe one day.

For now, I read, roast and try. And thanks to the support and knowledge of places like HB and CG, my knowledge base is increasing, my shots are 100% better than any commercial cafe in Ohio and my journey continues...
:wink:
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malachi
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Postby malachi » Nov 19, 2005, 12:10 am

It's a really humbling process.

I've given up trying to guess what the correct combinations are going to be - I've given up thinking I know enough to predict how coffees will react. Instead I just try to pay as much attention as possible and keep on tasting and trying.

There are just so, so many variables.
And when I try to wrap my brain about the inter-related dependencies - the effects and implications of changes to variables on other variables... It gets overwhelming really fast.

So I try to limit variables as much as possible and try to never jump to assumptions.


I think at a certain level, this is why I get frustrated sometimes with the focus on gear.
I just feel that, by paying total attention to the flavours in the cup and the results of changes to variables on that cup you can learn so so much more than by focusing on the gear.


And speaking of which - I think I've become distracted by the cool gear aspect of the GS3. I've spent more time measuring temp than tasting a single coffee under various conditions. Enough - time to get back to what matters... the coffee.

David - thanks for starting this thread.
Jim - thanks for sharing your insight.
and Dave... thanks for re-inspiring me.
"Taste is the only morality." -- John Ruskin

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Postby another_jim » Nov 19, 2005, 1:06 am

So, with all the baristas and alties dropping by, the tweaking discussions may be worth a thread for themselves. here's what I mean.

I usually have no good idea where to start with a new coffee, but I really fancy myself as being able to taste a shot and come up with how to tweak it next time. Of course, I've never really tested my skills by doing it with a bunch of other people. So I was wondering if all you guys were agreeing on the "next tweak" for a given blend, or whether you ll came up with different ideas. Is it "great minds think alike" or "too many cooks spoil the broth?" With a wonderfully tweakable machine like the GS3, it would be fun to get an idea of the process. and arguments, if any.

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malachi
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Postby malachi » Nov 19, 2005, 1:16 am

Unfortunately, I didn't really structure it that way and instead blew through a bunch of different coffees (rather than focusing on tweaking one towards perfection).

In retrospect - this was a mistake and a good illustration of what I mean when I say I let my inner-geek take over too much.
"Taste is the only morality." -- John Ruskin

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Walter
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Postby Walter » Nov 19, 2005, 7:27 am

cannonfodder wrote:You know, I have been trying to absorb everything I can over the past year of my espresso journey. I have read, tried, gotten Zen with and gone uber-techno-geek with equipment and beans. But these two posts are two of the best I have read.

I really wish I could spend a couple of leisure days with a professional barista just having a leisurely discussion about the tricks of the trade and sampling espressos prepared in different ways. I often wonder if those few of you that live close to Chris, Dan, Jim, Terry, Mark, (and the list goes on) realize how lucky you actually are. To be able to drive over to Chris's house and have shots from the mother of all home machines or a jam session at Counter Culture, maybe one day.

For now, I read, roast and try. And thanks to the support and knowledge of places like HB and CG, my knowledge base is increasing, my shots are 100% better than any commercial cafe in Ohio and my journey continues...
:wink:

I can only second that...

Thanks Chris & Jim!

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cannonfodder
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Postby cannonfodder » Nov 19, 2005, 11:03 pm

I have noticed that there tends to be two distinct trains of thought in the espresso world.

You have the technical geeks. The nuts and bolts (science) behind the process. Measurements, tests, and technology used to dissect the process, to learn exactly what a change in one of the dozens of variables will result in. Then use modern tech to minimize those variations (thermocouples, PID's, regulators, etc).

The second school of thought is the art of espresso. Don't worry about the nuts and bolts, it is what is on the other side of the portafilter that makes the difference. The Zen aspect, pulling shots by feel and frothing milk by sound and touch. No gauges, no measurements, pure instinct that has been developed by years of practice.

There is nothing wrong with either of these beliefs, nor do I believe that one can exist without the other. In order to maximize what you have in the cup, you need to understand the mechanics behind the process as well as poses a certain amount of intuition. Science meets art, or the GS3 meets the manual lever.

So chin up and push on with the tests and measurements because they are needed. They validate and prove the integrity and abilities of the machine. Then your experience, the art, of espresso is enhanced by the science of espresso. In the end you are rewarded with an ever increasing quality in the cup.
Dave Stephens

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malachi
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Postby malachi » Nov 19, 2005, 11:20 pm

So... how about those of us who feel that it's all important, but that the goal is actually understanding what is going on?


An example... everyone seems to have decided that flat line temp stability is "required" for good espresso. This is not based on a scientific process or on observation (IMHO). It is "unguided science." We have not bothered to taste and evaluate the results of various brew temp profiles in a structured and scientific manner.

The trouble is that you should measure as part of a planned process designed to evaluate - to prove or disprove an observation.

Without tasting - without that evaluation of the end product it's all just a form of intellectual masturbation.


So - where do those of us who value measurement and value the scientific method but understand that in the end it's what's in the cup that matters and that is what should drive scientific exploration fit?

I think the problem is always on the handle side of the portafilter.
But I spend a huge amount of time trying to understand, measure and control variables.

Where do I fit in?
"Taste is the only morality." -- John Ruskin