Now that we’ve established that our brewing equipment is sparkling clean, and we’re using good, hot water and coffee that’s been freshly roasted and ground, we need to look at the proportion of coffee to water.
About 30% of the coffee you use is the stuff that will be extracted into your final brew. These are the complex flavor compounds and oils that are the very essence of coffee. About 8% of these flavor compounds, however, are bitter, unpleasant flavors that you really don’t want in your cup. [Coffee is made up of over 800 flavor compounds, some far more desirable than others.] What we want to achieve is a well-rounded cup that exhibits all the good coffee characteristics, without dipping in to the baser aspects of the coffee. Our target then, is to extract between 18% and 22% of the total weight of the coffee into the final cup, leaving the final 8% of soluble but bitter compounds right where they are.
To reach this 18-22% extraction target, specialty coffee shops brew coffee by weight – 70 grams per liter. Since you may not have a digital gram scale on your kitchen counter, the specialty coffee trade has devised a standard coffee measure [SCM] of 14 grams of coffee, or two tablespoons per six ounces of water.
That probably seems like a *bunch* of coffee. In fact, it’s probably twice as much coffee as you use today. [I know it’s precisely twice as much coffee as I’d used for most of my coffee drinking life.] While the amount of coffee you use will ultimately be a matter of taste, it’s a good idea to use more coffee in the brewing cycle to achieve the right coffee extraction. Then, if you find that the resulting cup is too strong, you can add fresh, hot water to the final cup to dilute it to your tastes. And while all this may read like a lot of bother, you really owe it to yourself to try it, and see just how good your resulting coffee can be.
While these proportions present no problem to the commercial coffee brewer – or to those who brew using manual drip methods, or vacuum or press pots – you will likely find that, once again, the designers of home auto-drip brewing equipment have fallen down on the job… there are very few home drip brewers that have the capacity for these proportions of coffee. Quite literally, the basket runneth over.
One way to work around this problem is to brew less than the full capacity of your pot… say, six cups of coffee in an eight-cup pot. That leads us to the next part of our formula, and yet another problem to solve….
More problems!? Let’s take a look at time and turbulence!