I've recently beta tested a nifty system that gives direct and immediate feedback on your brewed coffee technique. It's called
"ExtractMoJo" from the George Howell Coffee Company, and it has helped me to brew the best non-espresso coffee I’ve ever made.
(OK, since I usually don’t drink a lot of non-espresso coffee, maybe that ain’t sayin’ much. But still, the brewed coffee’s been GOOD lately!)
The ExtractMoJo system consists of two parts. The first part is a computer program that quickly and accurately calculates the doses of coffee and water to prepare any size batch at your preferred proportions. The second part is a compact digital refractometer that, along with the software, allows you to determine the strength of your cup (aka, total dissolved solids) and the solubles yield (ie, what percent of the dry coffee went into the brew).
So why is this helpful?
Taste panels over the years have usually found that the best brewed coffee results when your technique is adjusted so that two criteria are met:
(1) 19-21% of the dry coffee mass is extracted into your cup and
(2) the resulting beverage ends up containing somewhere around 1.3-1.5% coffee solids.
It’s interesting to note that it’s NOT ENOUGH simply to start out with the proper proportions of dry coffee and water. It’s also necessary to tweak your temperature, grind, steeping time, and stirring to achieve that 19-21% extraction rate. This can be done by trial and error, for sure, but that can be a fairly lengthy process without experience. ExtractMoJo allows you to zero in on the right technique after only a few test brews.
OF COURSE you still have to adjust the coffee TO YOUR TASTE; no one and no system can decide for you what your coffee should taste like. In particular, the 1.3-1.5% coffee solids is very flexible depending on the coffee and your preference. But this system gets you in a reasonable range much more quickly, and allows you to reproduce your favorite recipes (for different coffees) at another time. And for a shop where many people prepare the coffee, it makes it relatively easy to create objective quality control standards that are verifiable and repeatable.
A side note: the refractometer may help to explain the mystery of why different clover and
vac pot stirring techniques have fiercely loyal adherents: up to a point, more stirring results in a bit more thorough extraction, and more extraction changes the flavor. We shall see as people experiment with these tools.
And, with a bunch more development, ExtractMoJo may become be useful for espresso brewing, too (I hope!) Espresso "standards" are hugely variable right now, and it would be great to be able to accurately make strength and solids yield measurements. Not to try and force people to make an arbitrarily "correct espresso," but simply to begin to understand how people are arriving at the particular flavor profile that they prefer. I believe that someday soon this technology will become
de rigueur for quality oriented coffee shops.
