To make cold brew coffee at home, stir coarsely ground coffee into cold water, using roughly one part coffee to five parts water for a concentrate or one part to eight for a ready-to-drink brew, cover it, and let it steep for about twelve to eighteen hours. Then strain it through a fine sieve and a paper filter, dilute it to taste, and keep it sealed in the fridge. That is the whole method, and it needs no special equipment.
Cold brew tastes different from hot coffee poured over ice because it never meets hot water. Cold extraction is slow and gentle, so it pulls out plenty of sweetness and chocolatey body while leaving behind much of the sharpness that heat brings out. This guide explains what makes cold brew what it is, gives you a reliable method and a ratio chart, shows how to strain without a specialist maker, and covers storage, serving and the most common problems.
Quick facts
- Cold brew is steeped, not poured. Grounds sit in cold or room-temperature water for many hours instead of minutes.
- Use a coarse grind, roughly like raw sugar. Fine grounds make it muddy, silty and bitter.
- Ratio decides strength. Around 1:4 to 1:5 makes a concentrate to dilute; around 1:8 to 1:10 is ready to drink.
- Steep about twelve to eighteen hours at room temperature, a little longer in the fridge.
- Strain twice and keep it sealed and cold. Clean straining and airtight storage keep it tasting fresh.
What cold brew is, and what it is not
Three drinks often get lumped together, and they are genuinely different. Cold brew is coffee steeped in cold or room-temperature water for many hours, then strained. Iced coffee is usually hot-brewed coffee that has been cooled and poured over ice, which keeps more of hot coffee's brightness and bitterness. Flash-brewed iced coffee, sometimes called the Japanese method, brews hot coffee directly onto ice so it chills instantly and keeps its aromatics.
Cold brew's character comes from time replacing heat. Hot water extracts coffee's aromatic acids and bitter compounds quickly; cold water extracts them slowly and less completely, while still dissolving plenty of the sugars and body. The result is smooth, round and low in perceived bitterness, which is why many people who find hot coffee harsh enjoy cold brew black. The trade-off is that some of the bright, fruity notes of lighter roasts stay behind, so medium and darker roasts often shine brightest as cold brew.
Takeaway: cold brew swaps heat for time. You get smoothness and sweetness at the cost of some brightness.
How to make cold brew, step by step
You need coffee, a jar or pitcher, water, a fine sieve and a paper coffee filter. A kitchen scale makes the ratio reliable, but spoons work too.
- Grind the coffee coarsely, or ask for a coarse grind when you buy it. Aim for particles roughly the size of raw sugar.
- Measure your coffee and water using the ratio chart below. For a first batch, try one part coffee to five parts water by weight for a concentrate.
- Combine and stir gently so every ground is wet. Dry pockets float on top and never extract.
- Cover and steep for about twelve to eighteen hours at room temperature, or around eighteen to twenty-four hours in the fridge.
- Strain once through a fine sieve to remove the bulk of the grounds, without pressing or squeezing them.
- Strain again through a paper filter to catch the fine sediment that makes cold brew taste muddy.
- Dilute to taste with water, milk or ice, then store the rest sealed in the fridge.
Patience at the straining stage pays off. Squeezing the grounds pushes bitter compounds and silt into the coffee; letting gravity do the work gives a much cleaner cup.
Takeaway: coarse grind, full wetting, long steep, gentle double strain. Each step protects the smoothness you are after.
Cold brew ratios and steep times
These are widely used starting points. Coffee varies, and so does taste, so treat them as a place to begin rather than rules:
| Style | Coffee to water (by weight) | Steep | How to serve |
|---|---|---|---|
| Strong concentrate | About 1:4 to 1:5 | 12–18 hours at room temperature | Dilute roughly half and half with water or milk |
| Ready to drink | About 1:8 to 1:10 | 14–18 hours at room temperature | Pour straight over ice |
| Fridge steep | Either ratio above | 18–24 hours in the fridge | Slightly softer and sweeter; serve as above |
| Small test batch | About 1:5 | Taste at 12, 15 and 18 hours | Find the steep time you prefer before scaling up |
If you do not have a scale, a rough volume guide for a concentrate is about one cup of coarse grounds to four cups of water. Brewing a concentrate is the most flexible option: it takes up less room in the fridge, and you choose the strength of each glass when you dilute it. For how ratios work across hot brewing methods as well, our guide to brewing pour-over coffee covers the hot side of the story.
Takeaway: make a concentrate at around 1:5, steep overnight, and dilute each glass to your taste.
Straining without a cold brew maker
Dedicated cold brew makers are convenient, but everyday kitchen equipment does the job just as well. What matters is removing both the coarse grounds and the fine sediment:
| Setup | How it works | Watch out for |
|---|---|---|
| Jar plus sieve plus paper filter | Steep loose in the jar, sieve out the grounds, then drip through a paper filter | Slow final filtering; be patient rather than squeezing |
| French press | Steep in the press, plunge slowly, then pour through a paper filter | The mesh alone lets fine sediment through |
| Nut-milk or fine cloth bag | Steep grounds inside the bag, then lift it out | Wash the bag thoroughly so old oils do not turn rancid |
| Pitcher with a filter insert | Grounds sit in a fine mesh core in the water | Coarse grind is essential or sediment escapes |
Whatever you use, clean it the same day. Coffee oils left on mesh and cloth go stale quickly and give the next batch a bitter, rancid edge.
Takeaway: any vessel plus a sieve and a paper filter makes excellent cold brew. The paper filter is what makes it clean.
Storing and serving cold brew
Keep cold brew sealed and cold. A tightly closed glass bottle or jar in the fridge protects it from absorbing other smells and slows the loss of flavour. Undiluted concentrate keeps a little longer than diluted cold brew, but both are best within a few days: the coffee does not become unsafe overnight, it simply grows flatter and duller. Dilute only what you are about to drink.
To serve, pour concentrate over ice and add water or milk to taste. Cold brew also makes excellent coffee ice cubes, which chill the next glass without watering it down. If you carry it to work, a double-wall vacuum cup keeps it cold for hours without dripping condensation on your desk or bag. Our titanium straw tumbler is a 420 mL double-wall cup in which the cup, straw and lid are all pure titanium, so nothing coated touches the coffee. For more on drinking iced coffee from metal without condensation or off-flavours, see our guide to cold brew and iced drinks in titanium, and for taking coffee further afield, our travel coffee kit guide.
Takeaway: sealed, cold and undiluted until you pour. Drink it within a few days while it still tastes bright.
Fixing common cold brew problems
Most disappointing batches trace back to grind, time or straining:
- Weak and watery: too little coffee or too short a steep. Use a stronger ratio before extending the time.
- Bitter or harsh: grind too fine, steep too long, or grounds squeezed while straining. Go coarser and strain gently.
- Muddy with sediment: skipped the paper filter. Strain a second time through paper.
- Sour or thin: under-extracted, often from a short steep in a cold fridge. Give it a few more hours.
- Flat and stale: old beans or cold brew kept too long. Brew smaller batches more often.
Takeaway: change one thing at a time, starting with the ratio, and keep notes on what worked.
Related reading: Coffee to Water Ratio: How Much Coffee per Cup, by Brew Method.
Related reading: How Long Does Brewed Coffee Last? Counter, Fridge and Flask.
Frequently asked questions
How long should cold brew steep?
Cold brew usually steeps for about twelve to eighteen hours at room temperature, or around eighteen to twenty-four hours in the fridge, where extraction is slower. Shorter steeps taste weak and sour; much longer steeps can turn woody and bitter. Taste a small batch at different times to find your preference.
What is the best ratio for cold brew coffee?
A good starting point is about one part coffee to five parts water by weight for a concentrate, diluted roughly half and half before drinking. For a ready-to-drink brew, use about one to eight or one to ten. Adjust the ratio for strength rather than stretching the steep time.
Is cold brew stronger than regular coffee?
Cold brew concentrate is strong, because it uses much more coffee per cup of water. Once diluted to drinking strength, it is broadly comparable to regular coffee, and the exact strength depends on your ratio and how much you dilute it. It usually tastes smoother, which can make it seem milder than it is.
Can you heat up cold brew coffee?
Yes. Dilute cold brew concentrate with hot water for a quick, smooth hot coffee, or warm it gently in a pan without boiling. It will taste rounder and less acidic than coffee brewed hot. Avoid reheating it repeatedly, which dulls the flavour further.
How long does cold brew last in the fridge?
Cold brew is best within a few days of brewing when kept sealed and cold, and undiluted concentrate holds up a little longer than diluted coffee. It rarely becomes unsafe quickly; it simply loses aroma and turns flat. Throw it away if it smells sour or musty, or if you see any mold.
Can you make cold brew with regular ground coffee?
You can, but finely ground coffee meant for drip machines tends to make cold brew muddy and more bitter, and it is harder to strain. If that is all you have, steep it for a shorter time and strain it carefully through a paper filter. A coarse grind gives a noticeably cleaner result.
The short version
Coarsely grind your coffee, combine it with cold water at around 1:5 for a concentrate, steep for twelve to eighteen hours, and strain twice, finishing with a paper filter. Dilute each glass to taste, keep the rest sealed in the fridge, and brew small batches often.
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