The golden ratio

The one number to remember

Most great coffee is 1:15 to 1:17 — one gram of coffee per 15–17 grams of water. Too little coffee: thin as a curate’s excuse. Too much: muddy and harsh. Start at 1:15 and adjust to taste.

Grind is the flavor dial

Finer grind: water helps itself to flavor faster. Coarser: it takes its time. Quick brews need fine; long steeps need coarse. Match the grind to the method and you’re 80% of the way there.

What the sizes look like

Coarse is rough sea salt (French press), medium is beach sand (drip), medium-fine is table salt (V60), fine is powdered sugar (espresso). Rub a pinch between your fingers: the whole measuring system, and it needs no batteries.

Coarse to fine

Put these brewers in order, coarsest grind first.

1. French press
2. Drip
3. V60
4. Espresso

French press, drip, V60, espresso. The quicker the water passes through, the finer the grind has to be.

Fine grounds, long steep

Fine grounds in a French press. Besides bitterness, what do you get?

Answer: Silt in the cup — the mesh can’t hold fines. Silt: a metal mesh cannot hold fine grounds back, and four minutes on them turns the cup bitter as well.

Water temperature

90–96°C is the zone. Off the boil, wait 30 seconds. Cooler flatters dark roasts; hotter wakes up light ones. Boiling water on a light roast is a rude awakening: scorched and bitter.

Off the boil

Kettle has just boiled. How long do you wait before pouring?

Answer: About 30 seconds. That drop lands you in the 90–96°C window without having to own a thermometer.

Brew one on paper

Both dials are live, so you can go the wrong way — the taste will say so. Brew, taste, change one thing, brew again.

Reach “That is the cup” in three brews: read each verdict, then make the move it points to.