"Espresso! My Espresso!"
An Ongoing Internet Novelette
by Randy Glass - Copyright 2013 - All rights reserved
E-mail me at firstname.lastname@example.org
Once Again Variables Are King
Tuesday, March 18, 2014
"How many times have I told you, one variable at a time?" If one of your parents were either a scientist or a barista, you probably heard this as a child more times than you would like to recall. Well, probably not, but it brings to our attention the science in espresso. And even if your parents had not drilled this into you, I have mentioned it a number of times though I do not take credit for inventing the scientific method.
I don't intend to go over all the variables in the process of creating an espresso. I have already covered that with much thought in my How-To, "12 - EASY GUIDE TO BETTER ESPRESSO AT HOME" Today's chapter centers around what happens when you forget that the foundation of success in science is controlling variables. I did just that.
A sentence to act as a refresher: "Change only one variable at a time in order to control the process." Grind, distribution, brew temperatures, brew force, roast level, dose,' and the rest of what sometimes seems like an endless list of things that can go wrong.. or right. In this case, wrong.
I had been recently struggling for about three or four days trying to get a good extraction. Channeling, sprites, and generally poor extractions. It was puzzling since everything I had been doing for nearly three years with the VBM DD and Kony had been going quite nicely. An occasional hiccup, but overall things had been good. Now this. It is not always easy to get a mental handle on the process first thing in the morning while sleep still holds a controlling 51% interest over your eyes, and a London fog is still drifting across your mind. But it finally clicked. Variables!
All that I had recently changed was:
Roast - I roasted to a Full City (just before second) and that is something I normally never do for espresso)
Jars - My wife had recently bought me a set of green-glass canning jars that all came with new lids.
On the fourth or fifth morning using this new roast, I opened the jar and heard the gentle "whoosh" of outgassing. "Wow!' I thought to myself. Still that fresh. That's special. And in a few seconds it hit me. Finally. Duh! My theory was that the lighter roast, even though only slightly lower, was taking a lot longer to degas as well as needing a longer rest, and combined with the new jars and new lids which afforded a much better seal, the beans were having a more difficult time in releasing their gas. Beyond that, I had to use this coffee after only one day's rest becasue I roasted too late in the last batch's life. You may say, "But that is three variables- lighter roast, fresher coffee, and new jars." Go ahead and say it, I'll wait... You are correct, but at this point I had to do something, and the cause was not my main concern. It was a solution I sought. It was, change two variables.
So I decreased the dose and made the grind a bit finer to compensate. I went from about 16.9 or 17 grams to 16.6 or 16.7. My theory was that this coffee needed more headroom for expansion. It worked. Lowering the dose gave me much better extractions two days in a row. How did I know just how much to lower the dose? .7 grams less? 3.2 grams? And should it be one division on the grinder or a tiny bit more? Instinct created out of experience.
Many things were learned: No matter how long you have been at this, things will still go wrong and you need to pay attention and use your experience to solve problems. They say that the definition of insanity is doing the same thing over and over while expecting a different result. If something is wrong with the extraction, change something! Don't keep doing the same thing expecting the machine to figure it out for you.
I think that might be a beginner's biggest difficulty; a fear of making changes that are too great based on the current set of parameters. What if we use "Fear of making too great a change in the grind setting"? Go ahead and change it three clicks. If done within the design parameters of the grinder, what can possibly happen? One of three things:
1 - The espresso will be worse
2 - The espresso will be the same
3 - The espresso will be better
That should inspire you. Those kind of stats put this one test at batting .666; you have a two out of three chance of at least a tie. That same approach applies to extraction time, extraction volume, brew temperature, and just about anything else over which you have control.
And in the end you most greatly benefit from learning what over-extracted, under-extracted, and properly extracted taste and look like. Excellent skills to carry forward at the cost of around fourty-five to around fifty grams of ground coffee.
Now, all you need to do is be awake and sufficiently alert to remember the lessons of the past, and then put two and two together. Sometimes it takes a couple of days.