This is the method we teach in the roastery. It assumes no equipment beyond a dripper, a filter, a kettle and a set of scales, and it takes about four minutes once you know it.
The numbers
Twenty grams of coffee. Three hundred and twenty grams of water at 94°C. A medium grind, roughly the texture of coarse sand.
The bloom
Pour fifty grams of water and stop. The bed will swell and release gas for thirty to forty-five seconds. Skipping this step is the single most common cause of sour coffee.
The pours
Add the remaining water in two even pours, keeping the bed submerged but never overflowing. Aim for a total brew time between two and a half and three and a half minutes.
Reading the result
Too fast and thin? Grind finer. Too slow and bitter? Grind coarser. Change one variable at a time, and change it in the same direction twice before deciding it was wrong.
