To make cold brew concentrate, combine 4 parts cold water with 1 part coarsely ground coffee by weight. Stir until every ground is wet, cover, and steep in the refrigerator for 12–16 hours. Strain through a fine filter, then dilute the concentrate with equal parts water or milk to start. Refrigerate it in a sealed container.
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Choose the 4:1 concentrate ratio
Cold brew concentrate starts with 4 parts cold water to 1 part coffee by weight. For a manageable batch, weigh 500 grams of water and 125 grams of coarsely ground coffee. This strong ratio is consistent with the concentrate method described by Mind Over Munch, which gives 8 ounces of water to 2 ounces of ground coffee.
A scale is preferable because a scoop of coffee can vary substantially by bean, grind, and how tightly it is packed. Choose a medium or dark roast if you want a fuller chocolate-like flavor, or use a lighter roast for more noticeable fruit and acidity.
Combine the coffee and cold water
Put the ground coffee in a clean, covered jar or pitcher, then add the cold water. Stir slowly for 30–60 seconds, scraping the bottom and sides until no dry pockets remain. Jeffrey Morgenthaler’s method also emphasizes wetting all the grounds before the main steep; dry grounds cannot contribute evenly to the extraction.
Cover the container and check that the coffee remains submerged. If grounds float in a dry layer, stir again before chilling. Do not seal a warm container or add hot water: this recipe is designed for a cold extraction, not hot-brewed coffee poured over ice.
Steep the mixture for 12–16 hours
Refrigerate the covered mixture for 12–16 hours. Start near 12 hours if you prefer a lighter, cleaner concentrate; use the longer end when the coffee tastes thin or lacks body. Seven Miles’ cold brew guidance treats concentrate as a base intended for later dilution, so judge the finished drink after mixing rather than tasting only a spoonful of undiluted liquid.
Do not extend the steep indefinitely to correct weak coffee. If the grounds are too coarse, the ratio is too dilute, or the batch was not fully wetted, extra time may add harshness without creating a balanced drink.
Strain twice for a cleaner concentrate
Strain the chilled mixture first through a fine-mesh strainer to remove the bulk of the grounds. Then pour it slowly through a paper coffee filter or clean cloth into a second container. The second pass takes longer, but it removes fine sediment that can make the concentrate gritty or muddy.
Let gravity do the work instead of pressing the grounds. Squeezing the filter can push sediment into the finished coffee and produce a more bitter taste. If the filter clogs, stop pouring, replace it, and continue with smaller batches.
Dilute and check the finished drink
Cold brew concentrate is ready when it smells clean and coffee-like and pours as a dark, strong liquid without a thick layer of grounds. Mix one part concentrate with one part cold water, milk, or a combination of both, then taste over ice. Add more dilution if it tastes sharp, heavy, or overly caffeinated; use less if it tastes weak.
For iced coffee with milk or ice, the ice will dilute the drink further as it melts. If you want a smoother topping, pair the drink with homemade cold foam after checking the base strength.
For a creamy topping, add homemade cold foam after checking the cold brew’s strength: homemade cold foam
Fix weak, bitter, or cloudy results
Weak concentrate: Check the ratio first. If you used too much water, reduce the dilution when serving rather than trying to rescue the entire batch. For the next batch, weigh the ingredients and steep for the full 12–16 hours.
Bitter or harsh concentrate: The coffee may have steeped too long, been ground too finely, or been pressed during straining. Dilute a small glass to test it. If bitterness remains strong, shorten the next steep and use a coarser grind.
Cloudy or gritty concentrate: Run it through a fresh paper filter. Cloudiness alone does not prove spoilage, but mold, a rotten odor, or a slimy texture means the batch should be discarded.
Too acidic: Try a darker roast, a slightly longer steep within the stated range, or more dilution with milk. Do not keep steeping past the range as the first fix.
Refrigerate and use the concentrate safely
Transfer the strained concentrate to a clean, covered container and refrigerate it promptly. Label it with the preparation date and use it within about one week for the best flavor. Always check the smell and appearance before serving; discard it if you see mold or notice an off odor.
Keep the concentrate separate from ice until serving so melting does not weaken the stored batch. When you are ready for a finished iced coffee, use the matching balanced iced coffee method to adjust the concentrate, ice, milk, and sweetener together.
Use this balanced iced coffee method to combine concentrate, ice, milk, and sweetener: balanced iced coffee method
Frequently asked questions
What is the best coffee-to-water ratio for cold brew concentrate?
A practical starting ratio is 4 parts cold water to 1 part coarsely ground coffee by weight. For example, use 500 grams of water and 125 grams of coffee. Dilute the strained concentrate with equal parts water or milk, then adjust to taste.
Can you make cold brew concentrate without a coffee filter?
Yes. Use a fine-mesh strainer first, then strain through a clean cloth, reusable fine filter, or paper towel-lined strainer. Pour slowly and avoid squeezing the grounds, which can push sediment and bitter flavors into the concentrate.
Should cold brew concentrate be refrigerated while it steeps?
Yes. Keep the covered mixture refrigerated during the 12–16-hour steep. Chilling also makes the finished concentrate ready to dilute over ice immediately after straining.
How long does homemade cold brew concentrate last?
Keep it sealed and refrigerated and use it within about one week for the best flavor. Discard it sooner if it develops mold, a rotten smell, or a slimy texture. Do not rely on dilution or reheating to make spoiled coffee safe.
Why is my cold brew concentrate not strong enough?
The usual causes are too much water, too little coffee, an incomplete wetting step, or a short steep. Check the ratio by weight and steep the next batch for the full 12–16 hours. Do not simply keep a weak batch at room temperature for longer.
