A bottle of cold brew concentrate with glasses of iced coffee

Cold Brew at Home: The 12-Hour Recipe

A 1:8 concentrate that keeps for a week, the right grind, and how to serve it through an Indian summer without watering it down.

Next post Previous post

Brew guide · 5 min read

Make it once. Drink it all week.

Cold brew is the only method where you do almost nothing and time does the work. Brew a concentrate on Sunday night and you have iced coffee until Friday.

The short answer

1 part coffee to 8 parts water, coarse grind, 12–16 hours in the fridge. 125g of coffee to 1 litre of water gives you a concentrate you dilute 1:2 or 1:3 with water, milk or tonic. It keeps for about a week refrigerated.

Concentrate — one litre

125g : 1000ml · 12–16 h
Grind
Coarse, like a French pressFine grounds make cold brew silty and, over twelve hours, genuinely bitter. Coarse is not optional here.
0:00
Combine and stirRoom-temperature filtered water into a jar or a French press. Stir until every ground is wet — dry pockets simply do not extract.
Fridge
12–16 hours, covered, coldIn the fridge rather than on the counter. In an Indian summer, room-temperature brewing for sixteen hours will start to ferment. Twelve hours is bright; sixteen is heavier and sweeter.
Filter
TwiceOnce through a fine mesh sieve to take out the bulk, then once through a paper filter or a clean cloth for clarity. Do not squeeze the grounds — that is where bitterness lives.
Serve
Dilute 1:2 or 1:3One part concentrate to two or three parts water or milk, over plenty of ice. Store the rest in a sealed bottle in the fridge for up to a week.

Three ways to serve it

Drink Build Notes
Iced black 60ml concentrate + 150ml water, full glass of ice The purest version. Use a coffee you would happily drink hot.
Cold brew latte 60ml concentrate + 150ml cold milk Do not add ice until the end or it dilutes twice.
Cold brew tonic 45ml concentrate + 150ml tonic water + a slice of orange The best hot-weather coffee drink there is. Pour the coffee over the tonic, not the other way round.

Which coffees suit it

Cold water extracts far less acidity, so bright washed coffees lose most of what makes them interesting. Cold brew flatters naturals, honeys and medium-dark roasts — anything with chocolate, dried fruit, caramel or nut. Fine robusta also works unusually well here, because the body carries through dilution.

Common mistakes

  • Grinding too fine. Twelve hours of contact with fine grounds gives you a muddy, harsh brew.
  • Squeezing the filter. It gets you a little more liquid and a lot more bitterness.
  • Brewing on the counter in summer. Above about 30°C for twelve hours you are fermenting, not brewing. Use the fridge.
  • Diluting with warm water. Everything should be cold. Ice is for chilling the glass, not the coffee.
  • Keeping it too long. A week refrigerated is the limit. After that it flattens and starts to taste like nothing.

Cold brew is not iced coffee

Iced coffee is brewed hot and chilled — it keeps its acidity and aroma and tastes like the coffee it came from. Cold brew never sees heat, so it is rounder, sweeter, much lower in acidity, and a bit further from the origin character. Both are good. They are not the same drink and neither is a substitute for the other.

Questions

Cold brew, answered.

What is the best cold brew ratio?

1:8 by weight for a concentrate — 125g of coffee to 1 litre of water — then diluted 1:2 or 1:3 when you serve. If you would rather drink it straight from the jar, brew at 1:15 instead.

How long does cold brew take?

12 to 16 hours in the fridge. Twelve gives a brighter, lighter result; sixteen gives a heavier, sweeter one. Past about eighteen hours it starts to turn woody.

How long does cold brew keep?

Sealed and refrigerated, about a week for concentrate. Once diluted, drink it within a day or two — it flattens quickly.

Can I make cold brew at room temperature?

You can, and it extracts faster — around eight hours. But in an Indian summer, twelve to sixteen hours at room temperature risks fermentation. Use the fridge.

Beans for the jar

Chocolate, fruit, body.

Shop the coffee →Coffee recipes