To make cold brew coffee at home you steep coarsely ground coffee in cold water for 12 to 24 hours, then strain it. That long, gentle soak pulls out a smooth, low-acidity concentrate that you dilute to taste and keep in the fridge. No machine, no heat, almost no skill required. If you can fill a jar, you can make cold brew coffee.
This guide walks through the grind, the ratio, the steep, the strain, and storage, plus the two main methods so you can match the result to the gear you already own. If you would rather track down a great glass than make your own, see our companion guide on finding cold brew and iced coffee near you.
What cold brew coffee actually is
Cold brew is coffee extracted with time instead of heat. Hot brewing uses near-boiling water to pull flavor out of grounds in a few minutes. Cold brew swaps that intensity for patience: cool water works slowly over many hours. Because heat is what drives the bitter, acidic compounds out of coffee, leaving the water cold means you get a rounder, sweeter, less sour cup. The trade-off is the wait.
It is worth being clear about what cold brew is not. It is not iced coffee. Iced coffee is hot-brewed coffee poured over ice, brewed fast and chilled. Cold brew is never heated. That single difference is why the two taste so distinct, and why cold water and a long brew really do belong together as one method rather than a hot brew you happen to serve cold. If you like the iced-coffee style instead, our guide to the hot and iced Americano covers that route.
What you need
- Coarsely ground coffee. Think raw sugar or breadcrumbs, the same coarse grind you would use for a French press. Fine grounds over-extract over such a long steep and turn muddy and bitter, and they are nearly impossible to filter out cleanly.
- Cold, filtered water. Room-temperature or refrigerator-cold both work. Better water means a cleaner cup, since coffee is mostly water.
- A jar, pitcher, or dedicated cold brew maker. Anything that holds liquid and has a lid will do the job.
- A way to strain. A fine mesh sieve, a nut-milk bag, a paper filter, or the built-in filter of a cold brew vessel.
Fresh beans matter here as much as anywhere. Coffee made from beans roasted in the last few weeks tastes noticeably sweeter than one made from stale, long-open grounds, so buy whole beans and grind them coarse just before you steep if you can. If you do not own a grinder, a shop can grind to a coarse French press setting for you, or see our coffee grinder guide for choosing one.
The cold brew ratio
Cold brew is usually made as a concentrate, a strong base you cut with water or milk later. That keeps it compact in the fridge and lets you dial strength per glass. The ratio is the one number that matters most, and it is measured by weight: parts of coffee to parts of water.
| Ratio (coffee:water) | Result | Best for |
|---|---|---|
| 1:4 | Very strong concentrate | Cutting heavily with milk, or small fridge space |
| 1:8 | Balanced concentrate | The reliable all-rounder; dilute roughly 1:1 |
| 1:16 | Ready to drink | Sipping straight, no dilution |
A 1:8 ratio is the easiest place to start: one part coffee by weight to eight parts water. Weighing on a kitchen scale is far more reliable than scooping, because grind and bean density throw off volume measures. Once you have brewed it once or twice, nudge the ratio to taste. A stronger concentrate is more flexible, since you can always add more water; a weaker one is more forgiving if you tend to over-dilute.
How to brew cold brew coffee step by step
This is the immersion method, the simplest and most popular way to make cold brew coffee. It is hard to get wrong.
- Weigh and grind. Grind your coffee coarse. For a standard jar, a common starting point is around 100 g of coffee to 800 ml of water, a 1:8 concentrate.
- Combine. Add the grounds to your jar, pour the cold water over them, and stir gently once so every ground is wet. No dry clumps should float on top.
- Cover and wait. Seal the jar and leave it 12 to 24 hours. The sweet spot for most palates is around 16 hours. You can steep on the counter or in the fridge; the fridge is slower and slightly cleaner-tasting, the counter a touch faster and bolder.
- Strain once. Pour the brew through a fine mesh sieve to catch the grounds, then through a paper filter or cloth to polish out the fines. Do not press or squeeze the grounds hard, which adds bitterness.
- Bottle it. Pour the strained concentrate into a clean sealed bottle or jar. Label it with the date.
- Dilute and serve. Fill a glass with ice, add concentrate, then top with water or milk. Start around 1:1 concentrate to water and adjust.
That is the whole method. The longer the steep, the stronger and more developed the flavor, up to a point. Past roughly 24 hours you start trading sweetness for woody, dull notes, so set a reminder rather than leaving it for days.
Immersion versus slow drip
There are two real ways to make cold brew, and they taste like different drinks.
Immersion (full steep)
The grounds sit submerged in the water for the whole steep. This is the jar method above. It gives a rich, full-bodied, rounded cup and needs nothing but a container and a strainer. The body is heavier and the flavors blend into one smooth wall of taste. It is the right choice for almost everyone making cold brew at home.
Slow drip (Kyoto-style tower)
Cold water drips slowly through a bed of grounds, drop by drop, into a vessel below, with the drip rate often set to about one drop per second. A full tower runs roughly 3 to 12 hours, commonly 8 to 12, depending on the batch size and drip speed. Because the water contacts the coffee only briefly, the result is brighter, cleaner, and more tea-like, with more delicate aromatics and individual notes like chocolate, berry, or citrus coming through separately. It needs a dedicated drip tower and some fiddling with the drip rate, so it is more of an enthusiast's setup than an everyday one.
If you are buying your first vessel, immersion gear is cheap and forgiving; slow-drip towers are a treat for people who already love the ritual. Either way, the core skills carry over from regular brewing, so our broader how to make coffee primer is a good companion.
How to store cold brew and how long it lasts
Keep cold brew in a sealed container in the fridge. Undiluted concentrate holds its quality best, often up to about two weeks, because the high coffee-to-water ratio slows staling. Once you dilute it, drink that batch within a few days, as the flavor fades faster. Always store it cold, and give it a sniff and a taste before drinking an older batch.
A few storage tips:
- Strain thoroughly first. Leftover fines keep extracting in the bottle and turn the brew bitter and silty.
- Use a clean, sealable bottle to keep fridge odors out.
- Make the concentrate, not the finished drink. Dilute glass by glass so each one tastes fresh.
Common mistakes and easy fixes
- Bitter or muddy: grind too fine or steeped too long. Go coarser and pull back toward 14 to 16 hours.
- Weak and watery: too little coffee, or you diluted too hard. Use more grounds or a stronger ratio, and cut the concentrate less.
- Cloudy or silty: not strained enough. Add a paper or cloth filter as a second pass.
- Sour or thin: often stale beans. Buy fresh, grind coarse just before steeping.
Ways to drink it
Diluted with cold water over ice is the classic, but the concentrate is a flexible base. Cut it with milk or oat milk for a smooth iced latte feel, sweeten with a splash of vanilla or simple syrup, or add a pinch of salt to round out any lingering bitterness. For a richer dessert-style drink, blend it the way you would a homemade Frappuccino-style blended iced coffee. Tonic water and a slice of citrus over a shot of concentrate makes a refreshing summer cooler.
The takeaway
Cold brew rewards patience more than technique. Get the grind coarse, the ratio roughly 1:8, and the steep between 12 and 24 hours, and you will have a smooth concentrate ready in the fridge whenever you want it. Tweak the strength and steep to your own taste over a few batches, and it becomes a no-effort habit. From here, explore the wider world of cold drinks in our coffee hub, or keep iced-coffee season going with more recipes and brewing guides.