Iced coffee can taste thin when hot coffee is poured straight over ice. Cold brewing takes a different route: the grounds steep in cold water, so the coffee is already cool when it’s time to serve.

This recipe makes a concentrate rather than a ready-to-drink brew. The strength of the finished glass depends on how much water or milk you add. The grind, steep and filter matter most when you’re making the concentrate itself.

Ingredients

Measure the coffee and brewing water by weight. The first two ingredients make the concentrate; the rest are for serving:

- 100 grams coarsely ground coffee

- 500 grams cold water

- Cold water or milk, for diluting

- Ice, for serving

- Simple syrup, optional

Grind and Roast

Grind the beans as you would for a French press, aiming for the texture of coarse sea salt. A fine grind can clog the paper filter and make the brew taste harsh. If the grounds are too coarse, the concentrate can taste flat.

If you buy ground coffee, check the grind rather than ruling it out altogether. Ask for a coarse grind at the counter if the packaged options are too fine. For the roast, try a medium Colombian or Brazilian coffee as a starting point rather than assuming a dark roast will work best.

According to Stephanie Hoffman, a certified coffee grader interviewed by TechRadar, a burr grinder gives more evenly sized grounds. If you grind at home, note the setting so you can repeat it when a batch tastes right. Hoffman also recommends filtered brewing water, so try that before changing beans if your tap water has a noticeable taste.

Steps

Use a 1-quart jar or pitcher for steeping. For straining, have a fine-mesh sieve, a paper coffee filter and a bowl ready. You’ll also need a clean jar with a lid for the strained concentrate. Then follow these steps:

1. Combine the grounds and cold water in the jar or pitcher. Stir once to wet all the grounds. Check that no dry grounds are sitting on the surface before you cover the container.

2. Steep for 12 hours on the counter or 16 hours in the refrigerator, where extraction is slower. Use those times as starting points. If the batch tastes thin, try a longer steep next time. If it comes out more bitter than you like, try a shorter one.

3. Line the sieve with the paper filter and set it over the bowl. Pour the coffee and grounds into the filter in batches, letting each batch drain before adding more. Let the coffee drain on its own. Pressing on the grounds can push fine particles into the concentrate and make it cloudy.

4. Pour the strained concentrate into the clean jar, seal it and refrigerate it. Keep it undiluted so you can decide how strong to make each glass when you serve it.

5. Mix equal parts concentrate and cold water or milk. For a 16-ounce glass, start with 4 ounces of concentrate and 4 ounces of water or milk, leaving room for ice. If you want a sweeter drink, stir in half an ounce of simple syrup before pouring the coffee over the ice.

Storage and Serving

The sealed, refrigerated concentrate holds its flavor for about a week. Whole milk gives the finished drink more body than skim milk, and oat milk also works if you prefer it. If you’re using regular ice, choose large cubes over crushed ice, which melts faster and dilutes the drink sooner.

Freeze leftover concentrate in an ice cube tray. Use the coffee cubes in your next glass to chill it without adding plain water as they melt.