Cold Brew at Home: An Easy Refrigerator Recipe

Cold brew extracts coffee slowly in cool water. It is convenient for batch preparation, but concentrated recipes and ready-to-drink recipes must not be confused.

Good starting point

For a ready-to-drink starting point, use 60 g coarse-to-medium coffee and 900 g cold potable water (1:15), then dilute or adjust to taste.

What to know before you begin

Cold brew is a process, not a standardized caffeine level. Caffeine varies with beans, dose, steeping and serving dilution.

Step-by-step method

1. Wash a food-safe container and prepare a filter system that can remove the grounds later.
2. Combine the coffee and water, ensuring all grounds are wet; cover promptly.
3. Steep in the refrigerator for roughly 12–18 hours as a starting experiment; keep chilled rather than leaving it on a warm counter.
4. Filter through a fine mesh and then paper if you want less sediment.
5. Store the finished drink refrigerated in a clean sealed container and use it promptly.

Problems to recognize

• Unexpectedly weak: a very coarse grind or low dose may be responsible.
• Sludgy: use a second paper filtration pass and avoid squeezing the muddy grounds.
• Strange odor or visible spoilage: discard; a recipe is not a food-safety guarantee.

Run a useful comparison

Prepare two small jars, one filtered at 12 hours and one at 18 hours, and taste chilled at equal dilution.

Think about dilution and safe handling

There are two separate recipes hiding under the label “cold coffee”: ready-to-drink cold brew that can be poured into a glass, and a stronger concentrate intended to be diluted. Record both the starting concentrate weight and the dilution water or ice so that you can reproduce a good glass. An iced hot brew needs an allowance for melted ice rather than simply pouring a full hot recipe over a large cup of ice.

Cold extraction is not the same as sterilization. Use clean food-safe containers, potable water and refrigerator storage where your recipe requires it. Do not assume an unrefrigerated brew is safe or assign a universal shelf life without suitable food-safety evidence.

Continue your coffee routine

For another practical angle, read Cold Brew Concentrate vs Ready-to-Drink. You can also explore Weak Coffee vs Under-Extracted Coffee when your next question is about the wider brewing workflow.

Reference and editorial note

Background reading: National Coffee Association cold brew guide. Ratios and settings here are starting experiments, not claims of firsthand equipment testing. This guide was prepared with AI assistance; the site owner must check all technical details and equipment-specific safety instructions before publication.