How to Make Cold Brew Coffee (Concentrate or Ready-to-Drink)

Cold brew is coffee made with time instead of heat. You steep coarse grounds in cold or room-temperature water for most of a day, then filter it. The result is smooth, chocolatey and low in perceived acidity, and you can keep a jar in the fridge for iced coffee all week.

You don’t need a special machine. A big jar, a sieve and some paper filters will do. This guide covers the ratios, the steps, the filtering options and the most common ways a batch goes wrong.

Cold brew calculator

Choose a style and how many drinks you want, and the calculator tells you how much coffee and water to use. It accounts for the water that the grounds soak up, so you actually end up with the amount you asked for.

Cold brew calculator

Strong concentrate 1:4Concentrate 1:5Ready to drink 1:8

How many drinks?

Drink size (before ice)

fl ozml

Coarse ground coffee

414 g

≈ 14.6 oz · 4.9 cups of whole beans

Cold water

70 fl oz

≈ 8.8 US cups

You’ll get

≈ 42 fl oz

of concentrate + 42 fl oz water/milk

Dilute about 1:1 with water or milk. Grind extra coarse, then steep 12–18 hours in the fridge (16–18 for the fullest flavor) or 12–16 hours at room temperature, and filter. The grounds soak up roughly twice their weight in water, which this calculator accounts for. Whole-bean volume is a rough estimate (~85 g per US cup).

You can also use the full-page cold brew calculator.

Concentrate vs ready-to-drink cold brew

There are two ways to make cold brew, and the only real difference is how much water goes in during the steep.

	Concentrate	Ready-to-drink
Ratio (coffee : water)	1:4 to 1:5	1:8
How to serve	Dilute with water, milk or ice	Straight over ice
Fridge space	Less; a small jar makes many drinks	More; you store the full volume
Flexibility	Adjust strength drink by drink	Fixed strength
Shelf life	Up to about 2 weeks	Best within a few days
Best for	Milk drinks, big batches, hot “cold brew”	Simplicity, black iced coffee

Concentrate is more flexible. You can make a strong iced latte, a lighter black iced coffee, or even a hot cup by topping it up with boiling water. It also takes less fridge space. Ready-to-drink is simpler: pour and go, no math.

If you’re new to cold brew, start with a 1:5 concentrate. It’s easy to dilute to taste, and hard to ruin.

What you need

• Coffee. Medium and dark roasts with chocolate, nutty or caramel notes are classic cold brew choices. Fruity light roasts can be lovely too, but they tend to taste flatter cold than hot.
• A grinder, or ask your roaster to grind coarse for cold brew. See our grind size chart for reference.
• A large jar or pitcher. A 1-quart (about 1 liter) mason jar is perfect for a small batch. A French press also works well.
• A fine-mesh sieve and paper filters (a pour over dripper or basket filter, or even a paper towel in a pinch).
• A scale. Ratios matter even more for cold brew than hot coffee, because you’re committing to a whole batch.

Prefer a dedicated setup? Systems like the Toddy Cold Brew System make large batches of concentrate and handle filtering for you, while the Hario Mizudashi pitcher is a slim, simple option for ready-to-drink cold brew. Our best cold brew makers guide compares more options.

How to make cold brew in a jar (step by step)

This recipe makes about 360 ml of concentrate, enough for three generous iced coffees after dilution, and fits comfortably in a 1-quart mason jar.

1. Grind the coffee coarse

Weigh 120 g of coffee and grind it extra coarse, like cracked peppercorns or coarse sea salt. Too fine and the coffee turns muddy and bitter and is hard to filter. Too coarse and you’ll need a very long steep.

2. Combine coffee and water

Put the grounds in the jar and add 600 g (600 ml) of cold or room-temperature filtered water. Pour slowly so all the grounds get wet.

3. Stir

Gently stir with a spoon or chopstick until there are no dry clumps, pushing the floating grounds under. A good stir now matters more than any stirring later.

4. Cover and steep 12–18 hours

Put the lid on and leave it:

• Room temperature: 12–16 hours. Extraction is faster, so check it at the 12-hour mark.
• In the fridge: 12–18 hours, with 16–18 for the fullest flavor. Slower extraction, but many people find the flavor cleaner. Up to about 24 hours is fine; beyond that it tends to get woody.

Starting it before bed and filtering it the next afternoon or evening fits most schedules.

5. Filter

Pour the mixture through a fine-mesh sieve into a bowl or pitcher to catch the bulk of the grounds. Then pour it through a paper filter to remove the fine sediment. Don’t press or squeeze the grounds; that pushes bitter, silty particles into your coffee. See the filtering options below.

6. Store and serve

Pour the filtered concentrate into a clean, airtight bottle or jar and refrigerate. To serve, fill a glass with ice and mix concentrate with an equal amount of water or milk. Adjust from there.

How to filter cold brew

Filtering is the slowest and messiest part of making cold brew. Here are your options:

Method	Clarity	Speed	Notes
Fine-mesh sieve alone	Low	Fast	Leaves silt; always a good first pass
Sieve + paper coffee filter	High	Slow	Cleanest result; swap filters if it clogs
Pour over dripper with filter	High	Slow	Easy to set on a jar; drip in batches
Cheesecloth (several layers)	Medium	Medium	Reusable if washed well; some fines get through
Nut milk bag or cotton brew bag	Medium–high	Fast	Can steep grounds inside it, then lift out
French press plunger	Low–medium	Fast	Convenient if you brewed in the press; follow with paper for a cleaner cup

How to dilute cold brew concentrate

Treat dilution as the final step of the recipe. Start with these and adjust to taste:

Concentrate brewed at	Dilute with	Good for
1:4 (strong)	About 2 parts water or milk to 1 part concentrate	Lattes, drinks with lots of ice
1:5 (standard)	About 1 part water or milk to 1 part concentrate	Everyday iced coffee
1:8 (ready-to-drink)	Nothing, or just ice	Black iced coffee

A few ideas:

• Iced coffee: 120 ml concentrate + 120 ml cold water over ice.
• Iced latte: 100 ml concentrate + 150 ml cold milk over ice.
• Hot cold brew: concentrate topped up with an equal amount of boiling water. Smoother, with less perceived acidity, than a regular hot brew.
• Coffee ice cubes: freeze diluted cold brew in an ice tray so your drink doesn’t get watered down.

How long to steep cold brew

Time and temperature work together. Colder water extracts more slowly, so fridge brews need longer.

Where it steeps	Starting point	Range
Room temperature (about 20–22 °C / 68–72 °F)	12 hours	12–16 hours
Refrigerator	16–18 hours	12–18 hours, up to about 24

Taste a spoonful before you filter. If it tastes weak and sour, give it a few more hours. If it’s starting to taste woody or bitter, filter it now and grind a little coarser next time.

How long does cold brew last?

• Concentrate: up to about 2 weeks in a sealed container in the fridge. It’s at its best in the first week, after which it slowly fades and can taste flat.
• Diluted or ready-to-drink cold brew: best within a few days. Dilute only what you’ll drink.
• With milk added: treat it like milk and drink it the same day.

Use a clean, airtight glass bottle or jar, and keep it in the main body of the fridge rather than the door, where temperatures fluctuate. If it smells sour or off, pour it out.

Cold brew troubleshooting

Problem	Likely cause	Fix
Weak and sour	Under-extracted: steep too short, grind too coarse, or fridge steep that needed longer	Steep longer; grind a bit finer; use a stronger ratio
Watery but not sour	Too much dilution	Dilute less, or brew at 1:4
Bitter or woody	Steeped too long or grind too fine	Shorten the steep; grind coarser; don’t exceed about 24 hours
Muddy or silty	Fines in the coffee	Filter through paper; let fines settle before pouring; don’t squeeze the grounds
Flat or stale	Old beans or concentrate stored too long	Use fresher coffee; store airtight; drink within the first week
Filter keeps clogging	Too many fines	Sieve first, let settle, then pour gently through paper

Cold brew vs iced coffee

They’re not the same thing. Iced coffee is usually hot-brewed coffee cooled down or brewed straight onto ice. It keeps more of the coffee’s bright acidity and aroma. Cold brew never touches hot water, so it tastes smoother, rounder and more chocolatey, with less perceived acidity.

If you want an iced drink in five minutes, try the iced pour over method in our pour over guide or the iced recipe in our AeroPress recipes. If you want a batch ready all week, cold brew wins.

How much caffeine is in cold brew?

It depends entirely on how you make and dilute it. Undiluted concentrate is very strong, so treat it like a syrup, not a drink. Once diluted as intended, a glass of cold brew is in the same general range as a mug of drip coffee, which the USDA puts at about 95 mg per 8 oz. For healthy adults, the FDA says up to 400 mg a day is not generally associated with dangerous, negative effects.

To estimate your own glass, try the caffeine calculator or read how much caffeine is in coffee.

Next steps

• Get exact amounts for any batch size with the cold brew calculator.
• Brewing in a French press? Our French press guide covers the plunger and cleaning.
• Ready for a dedicated system? See the best cold brew makers.
• Learn how ratios work across every method in our coffee to water ratio guide.