How To

15 bar vs 20 bar espresso machines: what the pump rating means, why shots brew near 9 bar, and the specs that matter more when you choose a home machine.

The espresso ratio guide for home baristas: dose, yield and shot time for ristretto, normale and lungo, with a 1:2 starting recipe and how to adjust it by taste.

Why is my espresso sour? The usual causes are a fast, under-extracted shot, low brew temperature or a short ratio. Here is how to diagnose each and fix it.