Every brewing guide opens with a ratio, and every ratio is wrong for somebody. I have been pouring the same coffee for three weeks now, changing one thing at a time, and the number I keep coming back to is not a number at all. It is a window.
The usual advice is sixty grams of coffee per litre of water. That is a fine place to begin, and if you never move away from it you will still make decent coffee. But the beans I am drinking this month are a washed lot, dried slowly, and they taste thin at sixty. At seventy they open up. Somebody else's roast would turn bitter at the same setting.
| Dose | Water | Time | What I got |
|---|---|---|---|
| 15 g | 250 g | 2:40 | Clean, a little hollow in the middle |
| 17 g | 250 g | 3:05 | Rounder, faint cocoa on the finish |
| 18 g | 250 g | 3:30 | Heavy, starts to dry the tongue |
What changed between the first row and the third was not only strength. The extra grounds slowed the drawdown, so the water spent longer in the bed, and the cup picked up flavours that had nothing to do with concentration. That is the part the ratio cannot tell you.
How I use it now
I set the ratio once, at the start of a bag, and then leave it alone for a week. Everything else I adjust: grind, pour pattern, how long I let the bloom sit. Once those are settled, if the cup still misses, I move the ratio by a gram and stay there for three days.
Three days is long enough to stop tasting what you expected to taste.
It is slower than chasing numbers, and it has made me much less interested in other people's recipes.