CHAMBERED COFFEE IN THE GRINDER

Dear Reader,

I want to take a moment to completely explain why ground coffee, trapped in the grinder between shots, makes it very difficult to control the flow-rate of the espresso shot.

Let’s start with the roasted coffee. The roasted bean will contain it’s own internal moisture after roasting. The higher the internal moisture in the bean the more coarse the grind will be to hit your perfect flow-rate on the extraction. (At Vivace our super ristretto shot is about 20ml oozing into the cup between 26 and 31 seconds. Espresso is so sensitive to the flow-rate that there are dozens of unique flavors within the time parameters).

Some varieties contain more moisture than others. Brazilian Porta-Rosa requires a coarser grind than any of our coffees, indicating a high internal moisture. Monsooned Malaber, despite being soaked in water for ten days or so, requires the finest grind of any of our varietals we use. It has the lowest internal moisture of any varietal I have ever pulled.

Ok so here’s the rub. When you turn off the grinder, ambient heat in the machine immediately begins to desiccate the coffee. The reduced moisture in the powder means the pour is faster using that powder…it’s a maddening game for the barista trying to gauge how long it has sat there and what it will do to the flow-rate. And it is quick, affecting the flow within one minute of idle residence time inside the grinder. And, my beloved old DRM machines contain 12 to 14 g of ground coffee total in the grinder. We cant throw out more than half a shot because the grinder has been idle for 2 minutes. It is true that after 5 minutes we purge that ground coffee out because oxidation has affected it noticeably at that point, but before that my baristi struggle to achieve the perfect shot.

Etzinger has the only doser design that works. Let’s see what he can do with the next commercial version, the Super Heavy coming out next year.