Cold Brew Coffee: How to Make It, Ratio, Steep Time, and 4 Mistakes

Cold brew coffee is made by steeping coarsely ground coffee in cold or room-temperature water for 12 to 24 hours. The result is a smooth, naturally low-acid concentrate with a heavier body than hot-brewed coffee. Cold brew is not iced coffee. Iced coffee is hot-brewed coffee poured over ice, which dilutes flavor and preserves acidity.

This guide covers ratio, grind, steep time, a no-equipment method, and 4 mistakes that ruin the batch.

Cold Brew Coffee Parameters at a Glance

How to Make Cold Brew Coffee at Home

Cold brew requires a coarse grind , the same texture as French press or slightly coarser. Fine grind in cold brew produces over-extraction and bitterness even without heat. The SCA extraction science framework explains why: cold water extracts soluble compounds more slowly than hot water. A coarser grind reduces surface area and prevents over-extraction during the long steep. For concentrate: 100g of coffee per 400ml of water (1:4). For ready-to-drink: 100g per 800ml (1:8). See our coffee ratio guide for how this compares to hot brew methods.

Add coarse ground coffee to a large Mason jar or pitcher. Pour cold or room-temperature filtered water over the grounds. Stir to saturate all the grounds. Cover and refrigerate for 18 to 24 hours. Strain through a paper-lined fine mesh strainer into a clean jar. Seal and refrigerate. Dilute concentrate 1:1 before serving. See our French press guide for an alternative method using a French press as the steep and strain vessel.

Heat extracts acids fast. Cold water extracts them more slowly. The result has similar caffeine to hot-brewed coffee but significantly less acidity and bitterness. As a concentrate, cold brew is higher caffeine per ounce. Diluting 1:1 brings it closer to drip strength. See our caffeine guide for how cold brew caffeine compares across brew methods and serving sizes.

One: grind too fine , produces over-extraction and bitterness despite cold water. Fix: coarse grind, same as French press. Two: too little coffee produces a weak, watery result. Fix: weigh both and use the correct ratio. Three: room-temperature steeping past 16 hours produces a harsh cup. Fix: move to the fridge after 12 hours. Four: poor straining leaves grounds in the liquid, which continue extracting. Fix: strain twice. See our coffee temperature guide for how temperature controls extraction across all brew methods.

Best Coffee for Cold Brew

Dark and medium roasts produce the best cold brew. Cold extraction amplifies body, chocolate, and caramel notes , characteristics dark roast carries in abundance. Blackout's Brewtal Awakening dark roast produces a cold brew concentrate that is bold, rich, and smooth with no sourness. Morning Reaper medium roast produces a slightly lighter result with more balance between body and brightness.

For large-batch brewing, our 5-pound bulk bags are the most economical option all summer. A 5-pound bag yields roughly 20 large batches at 1:4 concentrate. Browse our premium whole bean coffee , fresh-roasted, shipped within 1 to 2 business days.

Subscribe with the Blackout Coffee Club for 19% off every order with free shipping.

FAQ: Cold Brew Coffee

18 to 24 hours in the refrigerator, or 12 to 14 hours at room temperature. Refrigerator steeping is slower and forgiving , 24 hours rarely over-extracts. Room-temperature steeping past 16 hours turns bitter. Refrigerator overnight is the safest, most consistent approach.

Cold brew is steeped in cold water from the start , no heat involved at any stage. Iced coffee is hot-brewed coffee poured over ice. Cold brew produces a smoother, lower-acid cup because heat is never introduced. Iced coffee retains acidity and dilutes as ice melts.

Cold brew at a 1:4 concentrate ratio has roughly 2 to 3 times the caffeine per ounce of drip. Diluted 1:1, it is close to a strong drip cup. At 1:8, it is comparable to regular drip. Lower acidity also makes cold brew taste smoother at the same caffeine level. See our caffeine guide for exact caffeine comparisons by brew method.

Up to 2 weeks in a sealed container. After 2 weeks, flavor and aroma degrade noticeably. Concentrate lasts slightly longer than ready-to-drink. Always store in a sealed glass jar or airtight container. Do not leave grounds in the strained liquid.

No. A Mason jar, mesh strainer, and paper filter are all you need. A French press works well: add grounds, fill with cold water, refrigerate plunger-up, then press and pour. See our French press guide for exact parameters. For large batches, a dedicated cold brew vessel with a built-in filter simplifies straining at scale.

Fresh Beans Make Better Cold Brew

Browse our premium whole bean coffee , dark, medium, and light roast , all shipped within 1 to 2 business days of roasting.

Subscribe with the Blackout Coffee Club and save 19% on every order with free shipping.

Learn more about how we source and roast on our About Blackout Coffee page.

Follow Blackout Coffee on Instagram and Facebook for brewing guides, cold brew recipes, and new roast drops.