Cold brew coffee is made by steeping coarse-ground coffee in cool or cold water for an extended time, then filtering out the grounds. The result is a smooth, less acidic concentrate that you can dilute with water or milk. This guide covers the entire process: choosing the right grind, steeping in the refrigerator, filtering, and storing your brew.
Cold brew versus iced coffee
Cold brew and iced coffee are two different drinks. Iced coffee is brewed hot (using any method such as drip, pour-over, or espresso) and then chilled by pouring over ice or refrigerating. Cold brew is never heated; the grounds steep in cold water for many hours. Because hot water extracts more acids and oils, iced coffee can taste brighter and more bitter. Cold brew’s gentle extraction yields a smoother, sweeter, and less acidic flavor profile. For a broader look at the tools and vessels used for cold brewing, see our cold brew equipment guide.
Grind and ratio
Grind size
Use a coarse grind, similar to breadcrumbs or raw sugar. A fine grind will over-extract during the long steep, making the brew bitter and muddy. A consistent coarse grind also makes filtering easier. For a visual reference, check our coffee grind size chart.
Coffee-to-water ratio
The ratio depends on whether you want a concentrate or a ready-to-drink brew. A typical range for cold brew concentrate is between 1 part coffee to 4 parts water and 1 part coffee to 8 parts water (by weight). For a ready-to-drink strength, use a ratio of 1 part coffee to 10 to 16 parts water. You can adjust these ratios to suit your taste. For more detail on ratios, see our coffee-to-water ratio guide.
| Brew type | Coffee to water ratio (by weight) |
|---|---|
| Concentrate | 1:4 to 1:8 |
| Ready-to-drink | 1:10 to 1:16 |
Steeping in the fridge
Place the coarse grounds and water in a container, stir gently to ensure all grounds are wet, then cover and refrigerate. A common steeping time is 12 to 24 hours. Steeping longer than 24 hours can extract bitter compounds, while less than 12 hours may yield a weak brew. The refrigerator provides a consistent cool temperature that slows extraction and reduces the risk of spoilage. You can steep at room temperature, but the fridge is recommended for safety and repeatable results. A large jar, pitcher, or a dedicated cold brew maker all work for steeping.
Filtering
After steeping, you need to separate the liquid from the grounds. Several filtering methods work well:
- Pour through a fine-mesh sieve lined with a paper filter or a reusable nut milk bag.
- Use a dedicated cold brew maker that has a built-in micro-mesh filter.
- Line a colander with cheesecloth or a clean kitchen towel and strain into a bowl.
For the cleanest cup, filter twice: first through a coarse sieve to remove the bulk of the grounds, then through a paper filter or a fine-mesh strainer. Cold brew filter bags are a convenient option that you can place directly into the steeping container and remove when done. Always follow the manufacturer’s instructions for any filter or maker you use.
Concentrate and dilution
Cold brew concentrate is much stronger than regular brewed coffee. Drinking it straight can be overwhelming. A common dilution ratio is 1 part concentrate to 1 part water (or milk), but you can adjust to taste. Some people prefer a 1:2 or 2:1 ratio. Start with equal parts and add more water or milk until it tastes right. Concentrate also works well in cocktails, smoothies, or baked goods. Store the concentrate separately and dilute only the portion you plan to drink.
Storage
Keep cold brew concentrate in a sealed glass or food-grade plastic container in the refrigerator. Oxygen and light degrade flavor, so an airtight container is best. Cold brew concentrate can be stored for up to a week, though it’s best consumed within a few days for peak freshness. If you notice off odors or mold, discard the batch. Do not leave cold brew at room temperature for more than a few hours. Follow general food safety guidelines and your manufacturer’s recommendations for storage containers.
Do you need a cold brew maker?
A dedicated cold brew maker can simplify the process, but it is not required. A simple jar or pitcher works perfectly: you steep the grounds, then filter through a sieve or filter bag. Dedicated makers often have a built-in filter that lets you remove the grounds easily, and some include a spigot for dispensing. If you brew cold brew frequently, a cold brew maker may be a worthwhile convenience. For a detailed comparison of different styles, read our guide to cold brew makers.
Troubleshooting your cold brew
Most cold brew problems come down to grind, time or ratio, so change one thing at a time and keep notes.
- Weak or watery: use more coffee for the same water, steep a few hours longer, or dilute the concentrate less when you serve it.
- Bitter or harsh: shorten the steep, check that the grind is really coarse, and make sure the grounds were filtered out promptly instead of sitting in the brew.
- Muddy or gritty: filter a second time through paper, and avoid pressing or squeezing the grounds while straining, which pushes fine particles through.
- Flat or stale taste: start with fresher beans, store the finished brew sealed in the fridge, and drink it within the first few days.
- Sour notes: the steep may have been too short or the grind too coarse; extend the time a little before changing anything else.
Water matters too. Because cold brew is mostly water, a chlorine taste from the tap carries straight into the cup, so filtered water often makes a noticeable difference. For more on that, see the guide to water for coffee.
FAQ
Can I use regular ground coffee for cold brew?
Pre-ground coffee for drip machines is finer than ideal, so it tends to turn bitter and is harder to filter. If that is all you have, shorten the steep and filter through paper; for the best result, use a coarse grind. A burr grinder set to the coarsest setting works best.
How long does cold brew last in the fridge?
Cold brew concentrate can be stored in a sealed container in the refrigerator for up to a week. For the best flavor, drink it within a few days. Always check for signs of spoilage before using.
Can I steep cold brew at room temperature?
Yes, you can steep at room temperature, but the fridge is safer and produces more consistent results. Room-temperature steeping may extract faster, so reduce the time to 12–18 hours. Always use clean equipment and refrigerate after filtering.
Do I need to dilute cold brew?
Yes, unless you specifically made a ready-to-drink ratio. Cold brew concentrate is very strong and usually needs to be diluted with water or milk. Start with a 1:1 ratio and adjust to your taste.
Making cold brew at home is simple once you understand the basics of grind, ratio, and steeping time. Experiment with different ratios and steeping durations to find your preferred flavor. With a little practice, you’ll have a steady supply of smooth, refreshing cold brew.
