1

Use a coarse grind, close to what you would use for a French press. Fine grounds turn muddy and are hard to strain.

2

Mix one part coffee to eight parts cold water by weight, stir so every ground is wet, then cover. A large jar works perfectly.

3

Leave it for 12 to 18 hours. Room temperature brews a little faster and fuller. The fridge gives a cleaner, gentler cup.

4

Strain through a fine sieve lined with a paper filter or a clean cloth. What you have now is a concentrate.

5

Dilute it roughly half and half with water or milk, pour over ice and adjust to taste. Sealed in the fridge, the concentrate keeps well for about a week.