Cold brew coffee ratio for regular and concentrate

The cold brew coffee ratio that works for most people is 1:8 by weight for ready-to-drink strength and 1:4 to 1:5 for concentrate you dilute before serving. In kitchen terms, 1:8 means 100 grams of coarsely ground coffee to 800 ml of water. Get the ratio and the grind right and cold brew forgives everything else, because time does the extracting and you do almost nothing.

Ready-to-drink at 1:8

One part coffee to eight parts water gives you cold brew you pour straight over ice. A hundred grams of coffee and 800 ml of cold water in a jar, steeped overnight, strained in the morning. The result is smooth, full-bodied, and low in acidity. If it tastes too strong, move toward 1:10. If it tastes thin, tighten toward 1:7. Adjusting by one part at a time is the fastest way to find your number.

For a single batch in a standard one-litre mason jar, use 100 grams of coffee and 800 ml of water, which leaves headspace for stirring. The finished yield will be about 700 ml, because the grounds absorb roughly their own weight in liquid. Plan portions around the post-strain volume, which is always the smaller number.

Concentrate at 1:4 to 1:5

A hundred grams of coffee to 400 to 500 ml of water makes concentrate. Caffeine per millilitre is roughly double that of ready-to-drink, and the flavour is intense enough that drinking it straight is not pleasant. Dilute 1:1 with water, milk, or ice before serving. The cold brew concentrate ratio guide covers jar sizes, steep times and serving in more detail. Some people prefer 1:2 concentrate to water for a lighter cup. Over a full glass of ice, concentrate poured straight balances itself as the ice melts.

Concentrate is more practical than ready-to-drink if you share a fridge. It takes up less space and lets each person adjust their own cup. One batch of concentrate in a 500 ml jar serves about four cups when diluted, and the jar fits behind the milk carton instead of taking up an entire shelf.

Grind size

Coarse. Think raw sugar or breadcrumbs. A coarse grind slows extraction during the 12-to-24-hour steep, which is what you want. Fine grinds over-extract in that window and turn the whole batch bitter. They also clog most strainers and leave sediment in the finished brew that makes the last pour gritty.

If you are using a blade grinder, pulse in short bursts and stop when the largest pieces are about the size of coarse sea salt. Uniformity matters less for cold brew than for espresso or pour over, but very fine particles will still contribute bitterness, so err on the coarse side. You do not need a burr grinder for cold brew unless you are already making espresso or pour over and happen to own one.

Steep time and temperature

Twelve to twenty-four hours. Under twelve tends to produce sour, under-extracted cold brew. Over twenty-four risks bitterness, though cold brew is far more forgiving of overshooting than hot methods because the low temperature slows the extraction of harsh compounds.

Room-temperature steeping at around 20 degrees Celsius extracts faster. Twelve to sixteen hours is enough. Fridge steeping at around 4 degrees needs longer, eighteen to twenty-four hours, to reach the same extraction level. Room temperature pulls slightly more body and sweetness. The fridge produces a cleaner, lighter cup. The difference is subtle enough that fridge steeping is often the practical pick: set it up before bed, strain it when you wake up, and the timing just works.

Straining in two passes

Strain through a fine-mesh sieve first to catch the bulk of the grounds, then pass the liquid through a paper filter or cheesecloth to remove the remaining sediment. Two-stage straining is the difference between a clean, smooth cold brew and one that gets chalky at the bottom of the glass by the second day.

A French press handles the first stage. Press, pour into a jar, run the liquid through a paper filter for the second pass. Skipping the paper filter is fine if you drink the whole batch within a day or two. For anything longer, the fine sediment settles and makes the last few pours cloudy and gritty.

Shelf life

Cold brew keeps in the fridge for up to two weeks in a sealed container. The flavour is best in the first seven to ten days.

Glass is better than plastic for storage. Plastic absorbs coffee oils over multiple batches and develops a stale background note that is hard to wash out. A mason jar with a lid, a glass pitcher, or any bottle with a tight seal works.

Two adjustments worth the experiment

Replacing part of the water with milk before steeping produces something closer to an iced latte straight out of the jar, though dairy shortens the fridge life from two weeks to about three days. Oat milk works too.

A quarter teaspoon of salt per litre of water, dissolved before adding the grounds, reduces perceived bitterness without making the cold brew taste salty. Sodium suppresses bitter taste receptors on the tongue, and at a quarter teaspoon per litre the dose is small enough that the coffee does not read as salty. It does the most on a batch that came out slightly over-extracted.