Making cold brew at home looks more complicated than it actually is: one part coarsely ground coffee, four parts cold water, and a steep time that's shorter than you'd think. The result is a concentrate you dilute yourself. No fancy dripper required, no 24-hour wait because some blog once said so. Here's how to make cold brew coffee at home: the ratio, the grind, and three ways to do it.
TL;DR
- 1 part coffee to 4 parts water is the base cold brew ratio for a concentrate.
- Strength already maxes out after 6 to 7 hours: 24 hours isn't necessary.
- Coarse grind filters more easily but barely changes the strength.
- Cold brew tastes less acidic, even though its pH is nearly identical to hot coffee.
- A jar and a filter are enough: no dedicated equipment required.
What's the best cold brew ratio?
For cold brew concentrate, work with 1 part coffee to 4 parts water, roughly 250 grams of coarsely ground coffee to 1 liter of cold water. That concentrate is strong enough to dilute afterward with water, milk or ice, exactly the way you like it.
If you'd rather skip the dilution step and drink it straight, go for a looser ratio like 1:8 or 1:10. How much water you use mostly decides how much control you keep over the strength later on.
In 2023, research published in Applied Food Research tested the coffee-to-water ratio between 1:3 and 1:11. The ratio has a major effect on how much dissolves into the water and how acidic it tastes (Applied Food Research, 2023). Grind size and temperature mainly control how fast that process happens, not the ratio.
A coarser grind with a longer steep pulls more dissolved solids into the water, but that doesn't automatically make it taste better. In 2019, a tasting panel in Scientific Reports compared a 14-hour cold brew to a 22-hour version. Tasters clearly preferred the shorter brew, even though the longer batch contained more dissolved solids (Scientific Reports, 2019).
How long should cold brew steep?
Cold brew doesn't need 24 hours. Research shows caffeine and acid levels already hit their maximum after 6 to 7 hours. Steeping longer adds barely any extra flavor, but it does raise the odds of bitterness if your grind runs too fine.
In 2017, research published in Scientific Reports measured caffeine and acid levels in cold brew at different steep times. Levels plateau after 6 to 7 hours of steeping, well before the 10 to 24 hours most recipes call for (Scientific Reports, 2017).
In practice, you'll probably still set it up in the evening and pull it from the fridge the next morning. Anywhere between 12 and 16 hours works fine, purely for your own schedule's convenience, not because the coffee needs it.
What's the best grind for cold brew?
Coarsely ground coffee is the practical choice for cold brew: it filters more easily and gives a clearer result without sludge at the bottom of your glass. It barely changes how strong your finished concentrate ends up being, since that's mostly decided by the ratio and steep time.
That same 2017 Scientific Reports study found something else: coarse versus medium-fine grind barely changed the final caffeine and acid content of the concentrate (Scientific Reports, 2017). Grind size mostly determines how quickly you reach that plateau, and how easily you can filter afterward.
Go finer anyway, and expect a paper filter to clog faster while your concentrate stays cloudier. Coarse grounds with a nut-milk bag or fine-mesh sieve give you the cleanest cup.
Why does cold brew taste less acidic than hot coffee?
Cold brew tastes less acidic, but that's not because the pH is lower. In fact, the pH of cold brew and hot coffee sits in a similar, narrow range. The real difference is in how much of that acid you actually taste, not how acidic the liquid technically is.
In 2018, research published in Scientific Reports measured the pH of cold brew (4.96–5.13) and hot coffee (4.85–5.10). The two barely differed, but hot coffee clearly contained more of the acid you can taste on your tongue (Scientific Reports, 2018).
Brewing temperature pulls more of that perceptible acid out of the beans in hot coffee, not the acidity level itself. That's why cold brew feels rounder and softer in the mouth, even though the numbers tell a more nuanced story than "less acidic."
Does cold brew have more caffeine than regular coffee?
Cold brew does carry more caffeine than regular coffee, just not the double you often hear about. At the same roast and grind, cold brew concentrate holds proportionally more caffeine than hot coffee steeped for 24 hours. That's mostly down to how concentrated the brew is, not some caffeine boost from the cold process itself.
In 2017, Scientific Reports measured 1,230 mg of caffeine per liter in cold brew versus 970 mg per liter in hot coffee. Both used the same medium roast and coarse grind (Scientific Reports, 2017).
What you actually end up drinking depends mostly on how you dilute it. A strongly concentrated cold brew with little added water hits harder, caffeine-wise, than a lighter, more diluted glass.
How do you make cold brew step by step?
You don't need special equipment to make cold brew: a jar, a filter and cold water are enough. Already own a French press or a cold brew maker? Those work just as well. Use filtered or clean bottled water where you can: tap water with a strong chlorine taste comes through in the concentrate, especially after such a long steep.
Method 1: Jar or pitcher
This is the cheapest route and works with stuff you probably already own. Find the base ratio too strong or too weak? Shift it to 1:3 for a bolder concentrate or 1:5 for something milder; the rest of the steps stay the same.
- Combine 250 grams of coarsely ground coffee with 1 liter of cold water in a jar or large pitcher.
- Stir briefly so all the grounds get wet.
- Cover and leave in the fridge or on the counter for 12 to 16 hours.
- Strain the concentrate through a fine-mesh sieve, coffee filter or nut-milk bag.
- Store the concentrate sealed in the fridge.
Method 2: French press
Got a French press already? It doubles as steeping vessel and filter in one, no extra gear required.
- Add 60 grams of coarsely ground coffee to the carafe.
- Top up with 1 liter of cold water and stir briefly.
- Set the lid on without pressing the plunger down, and let it steep for 12 to 16 hours.
- Press the plunger down slowly to separate the coffee from the water.
- Pour the concentrate into a bottle or jar for storage.
Good odds you've already got one sitting in a cupboard, which makes this the fastest way to get started tonight.
Method 3: Dedicated cold brew maker
A dedicated cold brew maker, like a Toddy or an OXO-style setup, handles the filtering for you in exchange for one more gadget on your counter.
- Fill the reservoir with coarsely ground coffee and pour cold water over it.
- Let it steep for 12 to 16 hours, following the manufacturer's instructions.
- Open the drip valve or remove the filter to collect the concentrate.
You're paying for the convenience of a cleaner filter result and bigger batches in one go, not for any taste advantage over a jar.
Which beans work best for cold brew?
Beans with a chocolate or nutty profile work best for cold brew, since the cold steep already mutes a lot of the sharp acidity anyway. Go for a fruity single origin and you'll likely taste less of that brightness once it's concentrated.
A medium to dark roast usually gives the most predictable result: round, without sharp edges. Not sure which bean to grab? Browse the coffee beans and look for flavor notes like chocolate, nuts or caramel.
Fresh beans end up mattering more than the exact origin or the story printed on the bag. Coffee roasted more than a month ago loses aroma, and you'll taste that in cold brew just as much as in a regular cup. Torn between two similar roasts? Check the roast date, not the nicest label copy.
How do you serve and dilute cold brew concentrate?
Start with a 1:1 ratio: equal parts concentrate and water or milk. Some people prefer it stronger, closer to 2 parts concentrate to 1 part water, while others go lighter with more water for an easier everyday cup. Taste, then adjust, because the right dilution is purely personal preference.
Over ice, the concentrate keeps diluting itself as the cubes melt, so plan for a bit less water than you'd use without ice. Oat milk works well in cold brew: it blends in easily and doesn't clash with the softer acid balance.
Want it hot? Dilute the concentrate with hot water or warm milk instead of cold. That way you keep the same concentrate on hand for both cold and warm moments.
The concentrate is useful beyond a glass of water or milk, too. A splash in tonic with a lemon wheel makes a fresh, slightly bitter summer drink, no equipment required. In baking and dessert recipes, a bit of concentrate can replace liquid coffee extract, say in tiramisu or a coffee glaze. It often gives a rounder result than strongly brewed hot coffee. Store it exactly as you already do: these are extra uses, not a different brew.
Frequently Asked Questions
Is cold brew coffee healthy?
Cold brew fits into a normal diet just like any other coffee. It carries a bit more caffeine per liter than hot coffee, around 1,230 mg versus 970 mg, so keep an eye on how much you drink if caffeine affects you.
What's the difference between cold brew and iced coffee?
Cold brew steeps for hours in cold water into a concentrated base you dilute. Iced coffee is usually hot coffee that's cooled and poured over ice, often with a sharper taste. Want to try that instead? Read how to make iced coffee.
Can you make cold brew without special equipment?
Yes, a jar or large pitcher is enough. Mix coarsely ground coffee with cold water, then let it steep for 12 to 16 hours in the fridge. Strain the concentrate through a fine-mesh sieve or coffee filter before storing it.
Why is my cold brew bitter?
Usually it's a grind that's too fine, or a steep time that runs well past the point where the coffee stops getting stronger. Go coarser with the grind and stick to 12 to 16 hours of steeping.
How long does cold brew concentrate keep?
Sealed in the fridge, cold brew concentrate keeps for roughly two weeks. Smell and taste it before using: once the flavor turns flat or a bit sour, it's time for a new batch.
Can you drink cold brew hot?
Yes, dilute the concentrate with hot water or warm milk instead of cold and you've got a quick hot coffee. The flavor stays rounder and less sharp than coffee you brewed hot from scratch.
Making cold brew becomes routine after a few tries
The first batch is mostly a test: how fine you grind, how long you let it sit, how you like it diluted. After a few rounds you'll know exactly what works for you, and brewing it barely takes any thought at all.
Curious which beans are working well right now for a concentrate with a nutty or chocolate profile? See what's roasting →
