How to Make Cold Brew Coffee

The Basic Cold Brew Recipe

Cold brew is one of the most forgiving brewing methods. The basic recipe works in any container — a French press, a mason jar, a pitcher, or a dedicated cold brew maker.

The standard ratio

For ready-to-drink cold brew (no dilution): 1 part coffee to 8 parts water by weight. For example, 100g coffee to 800g water — fills a typical 1-quart mason jar.

For concentrate (intended to dilute with water, milk, or ice): 1 part coffee to 4-5 parts water. Concentrate is more practical because it stores compactly and you control strength per glass.

The procedure

1. Coarse-grind your coffee. Like coarse sea salt, similar to French press grind. Too fine and the cold brew gets muddy and bitter.
2. Combine coffee and water in your container. Stir gently to ensure all grounds are wet. No need for hot or warm water — cold filtered tap water is fine.
3. Cover and let it sit at room temperature or in the fridge for 12-18 hours. Room temperature extracts faster (12-14 hours), fridge slower (16-24 hours). Either works. Avoid going much past 24 hours — you start extracting bitter compounds.
4. Strain twice. First through a coarse filter (cheesecloth, French press plunger, or fine mesh strainer) to remove most grounds. Then through a paper coffee filter or cloth filter to catch fine sediment. The second strain is what separates good cold brew from gritty cold brew.
5. Store in the fridge. Cold brew lasts 7-10 days refrigerated, longer than hot-brewed coffee because the cold extraction doesn't pull out as many degradable compounds.

What Makes Cold Brew Different

Cold brew tastes notably different from iced hot coffee — sweeter, smoother, less acidic. The chemistry behind why is interesting.

Cold water extracts differently. Hot water pulls out a wide range of compounds quickly, including the acids and bitter alkaloids that give hot coffee its complexity (and sometimes harshness). Cold water extracts mostly soluble compounds — the sweetness, body, and core flavors — while leaving most of the acidic and bitter compounds behind. The result is naturally smoother and less acidic, which is why cold brew is often gentler on sensitive stomachs than hot coffee.

Lower acidity isn't always good. What cold brew gains in smoothness, it loses in complexity. The bright, fruity, tea-like notes that make great Ethiopian and Kenyan coffees distinctive don't come through as well in cold brew. Cold brew tends to highlight chocolate, nut, and caramel notes — flavors common in Latin American and darker-roasted coffees. For this reason, many people use medium-dark roasts for cold brew rather than trying to showcase delicate light roasts.

Caffeine content

Cold brew has more caffeine per ounce than drip coffee — typically 150-200mg per 8 oz cup of full-strength cold brew, vs. 95-130mg for drip coffee. The longer brew time extracts more caffeine, even though cold water extracts less of other compounds. Many cold brew commercial products are extremely caffeinated — Starbucks Cold Brew has about 200mg in a 16 oz "Grande," and a true cold brew concentrate undiluted can hit 400+mg per cup.

Variations and Improvements

Once you have the basic recipe down, several variations are worth trying.

Cold brew concentrate for batches

Use a 1:4 ratio (e.g., 200g coffee to 800g water). After brewing and straining, you have concentrate that lasts 2 weeks in the fridge. To serve, dilute with cold water, milk, or ice in a 1:1 ratio (concentrate to dilution). This stores far more compactly than full-strength cold brew and lets you adjust strength per glass.

Japanese iced coffee (the alternative)

Cold brew isn't the only way to make iced coffee. "Japanese iced coffee" or "flash chill" pours hot pour-over coffee directly over ice. The hot water extracts the full flavor profile (preserving acidity and complexity), while the ice immediately cools it — preserving the aromatics that hot brewing produces. This method takes 5 minutes vs. 12+ hours for cold brew, and many specialty coffee professionals prefer it for showcasing single-origin beans. Recipe: brew pour-over normally but reduce water by 1/3, replace with crushed ice in the carafe. The melting ice makes up the difference.

Nitro cold brew at home

Nitro cold brew (cold brew infused with nitrogen, served on tap with creamy texture) requires either commercial keg equipment ($300+) or a whipped cream charger system using nitrogen cartridges (around $60). For most home users, it's not worth the setup, but if you're a cold brew enthusiast, the texture difference is real and dramatic.