Brewing

Cold Brew at Home and Café-au-Lait Concentrate

2026-08-31 · 3 min read

When summer turns humid, hot coffee loses some of its appeal. Japanese cafés answer with mizudashi (water-brewed) coffee and bottles of café-au-lait base—concentrated coffee you dilute with milk. Both are easy to make at home and keep in the fridge for several days.

Cold brew vs iced coffee

• Iced coffee is brewed hot and chilled, often by pouring directly over ice. It keeps bright aromatics and acidity.
• Cold brew steeps ground coffee in cold or room-temperature water for many hours. It is smoother, lower in perceived acidity and naturally sweet, with less aroma.

Neither is better; they are different drinks.

Simple cold brew (mizudashi)

Ratio: 1 part coffee to 10 to 12 parts water by weight for a ready-to-drink brew.

Ingredients for about 1 litre

• 80 to 100 g coffee, medium-coarse grind
• 1 litre cold filtered water

Method

1. Put coffee in a jar or a cold-brew pitcher with a mesh filter (or use a large tea bag or nut-milk bag).
2. Add water slowly, stirring gently so all the grounds are wet.
3. Cover and refrigerate for 8 to 14 hours. Medium-dark roasts suit shorter times; lighter roasts can go longer.
4. Strain through paper or fine cloth.
5. Keep sealed in the fridge and drink within 3 to 4 days.

Café-au-lait base (concentrate)

A concentrate saves space and lets you adjust strength.

Ratio: 1 part coffee to 4 to 5 parts water.

Method: Steep 200 g coarse ground medium-dark coffee in 1 litre cold water for 12 to 18 hours in the fridge, then strain twice (mesh, then paper). Store sealed for up to a week.

To serve: 1 part concentrate to 2 to 3 parts milk over ice. Taste and adjust. Add sweetener only if you like; many people find cold brew sweet enough unsweetened.

Choosing beans

Medium to medium-dark blends with chocolate, nut and caramel notes are the most forgiving. Very light, floral coffees can taste flat as cold brew; brew those as iced pour-over instead.

Iced pour-over (Japanese iced coffee)

1. Use your normal dose, say 20 g coffee.
2. Put 120 g ice in the server.
3. Brew with 180 g hot water, slowly, so the coffee drips directly onto the ice.
4. Stir and serve over fresh ice.

This keeps aroma vivid, which is why many specialty fans prefer it.

Food safety and storage

• Use clean, sealed containers.
• Keep refrigerated at all times.
• Discard if it smells sour or off.
• Never leave cold brew at room temperature for long periods.

Ideas for using concentrate

• Coffee jelly: set sweetened concentrate with gelatine or agar, cube, and serve with cream.
• Affogato-style: pour over vanilla ice cream.
• Baking: add a spoonful to brownie batter or tiramisu.

A slow coffee for slow afternoons

Cold brew asks for planning but almost no skill. Set it up after dinner, strain it in the morning, and you have smooth coffee for the next few days—the kind of quiet, dependable cup that suits a hot afternoon.

Written for the Yeti Fazenda Coffee Journal, an independent coffee resource. More from the journal →