18 g in, 36 g out: why the 1:2 ratio became the default
The 1:2 benchmark traces back to basket geometry and refractometer surveys. Here is the data showing when to leave it and when to return.
Brewing lab notes
Every post ends with a shot log table: dose, yield, time, TDS, extraction yield and the single variable changed. No tasting notes without numbers behind them.
Latest articles
Two articles published, four in the lab queue. Sorted newest first.
Refractometer dial-in: reading TDS without guesswork
How to run a five-shot TDS series, convert to extraction yield, and decide grind direction with fewer than ten tasting pulls.
Burr geometry and fines: what actually causes bitterness
Particle distributions from six grinders, mapped against astringency scores. Conical versus flat, and where channelling really starts.
Scheduled
Water chemistry 101: hardness, alkalinity and sweetness
Target ranges for calcium, magnesium and bicarbonate, with three recipes tested side by side on the same bean and grind setting.
Scheduled
9 bar is not sacred: pressure profiling explained
Flat, declining and pre-infusion profiles compared at 6, 8, 9 and 11 bar — extraction yield curves and flow-rate tables for each.
Scheduled
Light roast espresso: higher temp, finer grind, longer ratio
A step-by-step dial-in protocol for dense light roasts, with logged corrections from 92 °C to 96 °C and 1:2.0 to 1:2.6.
Scheduled