Cold brew coffee is easy to make at home with a jar, coarse-ground coffee, cold water, and enough time for a slow steep. This method produces a smooth coffee concentrate that you can dilute, sweeten, or turn into iced coffee whenever you want.
What You Need
For one medium batch, gather:
- 1-quart (about 1-liter) glass jar with a lid
- 1 cup coarsely ground coffee
- 4 cups cold or room-temperature filtered water
- A spoon or chopstick for stirring
- A fine-mesh sieve, cheesecloth, coffee filter, or clean kitchen towel
- A second jar, bowl, or large measuring cup for filtering
- Ice and milk or water for serving
The basic ratio is 1 part coffee to 4 parts water by volume. This creates a fairly strong concentrate. If you prefer a ready-to-drink cold brew, use 1 cup of coffee with 6 cups of water instead, or dilute the finished concentrate more generously.
Use coffee that you enjoy drinking as regular brewed coffee. Medium or medium-dark roasts are common choices, but light roasts can work well if you prefer brighter, fruitier flavors. Freshly ground beans usually taste more aromatic than pre-ground coffee.
Choose the Right Coffee Grind
A coarse grind is important because cold brew steeps for many hours. The grounds should look similar to coarse sea salt or cracked pepper, not like flour or fine sand.
A grind that is too fine can cause several problems:
- The coffee may taste bitter or harsh.
- Filtering can take a long time.
- Fine sediment may pass through the filter.
- The grounds can clog paper filters and make the process frustrating.
If you grind coffee at home, use a coarse setting. If you buy coffee already ground, ask for a coarse grind intended for cold brew or French press. Some sediment is normal, especially when using a metal sieve, but the finished drink should not feel gritty.
Step-by-Step Method
1. Add the Coffee to the Jar
Place 1 cup of coarsely ground coffee in a clean 1-quart jar. A wide-mouth jar is easiest to fill and clean, although any food-safe container with a lid will work.
Avoid packing the grounds down. They need room to absorb water and release their flavor evenly.
2. Add Cold Water
Pour 4 cups of cold or room-temperature water into the jar. Add the water gradually rather than all at once if the grounds tend to float. This helps wet more of the coffee evenly.
Use the back of a spoon to gently press down any dry patches. Stir slowly for about 30 seconds, scraping the bottom and sides of the jar so that all the grounds are saturated.
Do not shake the jar vigorously. Vigorous agitation is unnecessary and can make filtering more difficult by breaking up the grounds and creating extra sediment.
3. Cover and Steep
Put the lid on the jar and place it in the refrigerator or on the counter, depending on your preference and schedule. Let the coffee steep for 12 to 18 hours.
The refrigerator produces a slower extraction and may give you a slightly softer, less intense result. Steeping at room temperature is faster, but the coffee should be filtered promptly once it reaches the desired strength.
Use this guide as a starting point:
| Steeping time | Typical result | Best adjustment |
|---|---|---|
| 8–10 hours | Lighter and less concentrated | Use less dilution when serving |
| 12–14 hours | Balanced and smooth | Good starting range for most batches |
| 16–18 hours | Stronger and fuller-bodied | Dilute with more water or milk |
| Over 20 hours | More intense, sometimes woody or bitter | Usually not necessary |
Time is not the only factor. Grind size, coffee variety, water temperature, and the coffee-to-water ratio all affect the final taste. If your first batch is weak, steep slightly longer or use more coffee next time. If it is bitter or overly heavy, shorten the steep or use a coarser grind.
4. Filter the Coffee
Set a fine-mesh sieve over a second jar, bowl, or measuring cup. Pour the coffee and grounds through the sieve slowly.
For a cleaner result, line the sieve with a paper coffee filter, cheesecloth, or a clean, lint-free kitchen towel. Paper filtering takes longer, but it removes more fine particles and produces a smoother drink.
If the filter clogs, do not press hard on the grounds. Pressing can force muddy sediment through the filter and may extract harsh flavors. Instead, let the liquid drain gradually, replace the filter, or filter the coffee in two smaller batches.
A practical two-stage method is often easiest:
- Pour the steeped coffee through a fine-mesh sieve to remove the bulk of the grounds.
- Run the strained liquid through a paper coffee filter for a clearer finish.
Discard the used grounds or add them to compost if appropriate. Do not pour a large amount of grounds down the sink, because they can contribute to clogged drains.
5. Store the Cold Brew
Transfer the filtered coffee to a clean jar or bottle with a tight lid. Keep it refrigerated and use clean utensils whenever you pour or dilute it.
Cold brew is best enjoyed while it tastes fresh. For quality and food-safety reasons, make small batches and use them within about a week. If the coffee develops an unusual smell, visible mold, carbonation, or an unpleasant flavor, discard it rather than trying to rescue it.
How to Serve Cold Brew
The concentrate is usually diluted before drinking. Start with equal parts cold brew and water, then adjust to taste. Stronger batches may need two parts water to one part concentrate.
For a simple iced coffee:
- Fill a glass with ice.
- Add 4–6 ounces of cold brew concentrate.
- Add an equal amount of cold water.
- Taste and adjust the strength.
For a cold brew with milk, combine 4 ounces of concentrate with 2–4 ounces of milk, half-and-half, or a plant-based alternative. Oat, almond, soy, and coconut beverages each change the flavor and texture in different ways.
Other serving ideas include:
- Add a small amount of simple syrup while the coffee is cold.
- Use maple syrup for a deeper, breakfast-style sweetness.
- Add a splash of vanilla extract or cinnamon syrup.
- Freeze diluted cold brew in ice cube trays so melting ice does not water down the drink.
- Pour cold brew over a scoop of vanilla ice cream for an easy coffee float.
- Mix it with tonic water for a bright, bitter, sparkling drink.
- Use it in smoothies or coffee-flavored desserts.
Sugar dissolves poorly in very cold liquid. If you want a sweetened batch, use liquid syrup, dissolve sugar in a small amount of warm water first, or sweeten each glass individually.
Ratios for Different Strengths
The 1:4 ratio is a useful concentrate, but it is not the only option. Try one of these starting ratios:
- Milder concentrate: 1 cup coffee to 5–6 cups water
- Standard concentrate: 1 cup coffee to 4 cups water
- Strong concentrate: 1 cup coffee to 3 cups water
- Ready-to-drink style: 1 cup coffee to 7–8 cups water
The volume of coffee grounds makes ratios somewhat approximate because different beans and grind sizes take up different amounts of space. For repeatable results, weigh the ingredients with a kitchen scale. A good starting point is around 100 grams of coffee to 800 grams of water for a 1:8 ready-to-drink brew, or 100 grams of coffee to 400 grams of water for a stronger concentrate.
If you use a scale, measure water by weight because 1 gram of water is approximately 1 milliliter. This makes it easier to reproduce a batch from one jar to the next.
Troubleshooting Common Problems
The coffee tastes bitter
The coffee may have steeped too long, been ground too finely, or been made with a dark roast that produced more roasty bitterness. Dilute it first to see whether the strength is the main issue. For your next batch, use a coarser grind, reduce steeping time, or choose a medium roast.
The coffee tastes weak
Use less dilution when serving, or increase the coffee-to-water ratio next time. You can also steep for a few additional hours, although adding more coffee is often a cleaner adjustment than steeping for an extremely long time.
The coffee tastes sour or thin
Under-extraction can result from too short a steep, a very coarse grind, or insufficient contact between water and grounds. Stir thoroughly when you begin and allow at least 12 hours for a typical batch. A slightly finer coarse grind may help, but avoid grinding as fine as drip coffee.
There is a lot of sediment
A metal sieve alone will let fine particles through. Use a paper coffee filter for the final pass, and avoid squeezing the grounds. Let the coffee settle in the refrigerator for a few hours, then carefully pour the clearer liquid into another container if sediment remains at the bottom.
The filter drains too slowly
The grind may be too fine, the filter may be overloaded, or the grounds may have been stirred aggressively. Filter in smaller batches, change the paper filter, or perform a coarse sieve pass before using the paper filter.
The cold brew is too concentrated
That is usually easy to fix. Add cold water or milk a little at a time until the drink tastes balanced. Record how much dilution you used so you can prepare the next batch closer to your preferred strength.
Helpful Variations and Limitations
You can steep cold brew with flavored beans, but flavored syrups are easier to control after filtering. Adding spices, citrus peel, cocoa nibs, or vanilla directly to the jar may create interesting flavors, though these additions can make filtering harder and may become overpowering during a long steep.
You can also brew in a French press, pitcher, or dedicated cold-brew maker. A jar is inexpensive and convenient, but it has no built-in filter, so straining takes more effort. The jar method is also less suitable for making very large batches because filtering a full container can be slow and messy.
Cold brew is not automatically lower in caffeine than hot coffee. The caffeine level depends on the coffee amount, bean, ratio, serving size, and dilution. Because cold brew concentrate is often served in a larger or stronger portion, measure your serving if caffeine intake matters to you.
Finally, cold brew should not be left indefinitely at room temperature. Refrigeration slows quality loss, but it does not make the coffee permanent. Keep the container covered, avoid drinking directly from the storage jar, and make a fresh batch when the flavor starts to fade.