Cold Brew Coffee: How to Make It, Ratios and Best Beans

Cold brew coffee is coffee made by steeping coarsely ground beans in cold or room-temperature water for 12 to 18 hours, then filtering out the grounds. To make it, mix 1 part coffee with 8 parts water for a concentrate (or 1:12 to 1:15 to drink straight), steep it covered in the fridge, strain, and dilute to taste. It tastes smooth, sweet and less sour than hot coffee.

In this guide

• What is cold brew coffee?
• How to make cold brew (step by step)
• Cold brew ratio chart for 500 ml, 1 L and 2 L
• How to dilute cold brew concentrate
• How long does cold brew last?
• How much caffeine is in cold brew?
• Is cold brew less acidic?
• Best beans and grind for cold brew
• Common cold brew mistakes and fixes
• Cold brew drink ideas
• FAQ

What is cold brew coffee?

Cold brew uses time instead of heat. Coarse grounds sit in cold or room-temperature water for many hours, and the slow extraction gives a coffee that is smooth, rounded and naturally sweet, with less of the sharp, sour bite of hot coffee.

Cold brew vs iced coffee: iced coffee is brewed hot and then cooled or poured over ice, so it is quick to make and keeps more of the bright, aromatic notes of hot coffee. Cold brew takes 12 hours or more but tastes mellower and holds up better to milk and ice. Read the full comparison in iced coffee vs cold brew: the real difference.

How to make cold brew (step by step)

You only need coarsely ground coffee, clean drinking water, a jar, pitcher or French press, and a way to filter (a fine sieve plus a paper filter or clean cloth).

1. Weigh and grind. Use a coarse, even grind. For 1 litre of concentrate, use 125 g of coffee (1:8). For a ready-to-drink batch, use 67 to 83 g per litre (1:15 to 1:12).
2. Add water and stir. Pour in cold, filtered water and stir gently so every ground is wet. Dry clumps floating on top will under-extract.
3. Cover and refrigerate. Close the container and put it in the fridge. In the Philippine climate, where room temperature is often around 30°C, we recommend steeping in the fridge for cleaner flavour and better food hygiene.
4. Steep 12 to 18 hours. Start at 14 to 16 hours. Taste it: go shorter if it is bitter or woody, longer if it is thin. Fridge brewing is slower than room-temperature brewing, so it needs the longer end of the range.
5. Filter. Pour through a fine sieve, then through a paper filter or clean cloth for a clear brew. Do not squeeze the grounds; that pushes bitter, muddy fines into the coffee. A French press makes this step easy: press slowly, then pour through a paper filter.
6. Dilute and serve. Mix concentrate with water or milk (see below), add ice, and sweeten if you like.
7. Store. Pour into a clean, sealed bottle and keep it in the fridge.

Cold brew ratio chart for 500 ml, 1 L and 2 L

Ratios are coffee to water by weight (1 ml of water weighs 1 g). The grounds soak up some water, so you will get back a little less liquid than you put in.

A 200 g bag makes about 1.6 litres of 1:8 concentrate, which becomes about 2.5 litres of drinks once diluted. A 1 kg bag is the better value for a café or a household that drinks cold brew daily. For hot brewing ratios, see our coffee-to-water ratio chart.

How to dilute cold brew concentrate

A 1:8 concentrate is too strong to drink straight for most people. Start by mixing it 1:1 with cold water or milk, then adjust.

Remember that ice melts into the drink. If you like a strong glass, use less water and let the ice do some of the diluting, or use coffee ice cubes.

How long does cold brew last?

Keep cold brew in a clean, sealed bottle in the fridge. For the best flavour, drink ready-to-drink cold brew within about a week. Undiluted concentrate is commonly kept for up to about two weeks, but the taste flattens and turns stale over time, so we suggest making smaller batches more often. Once you add milk or sugar, treat it like any milk drink and finish it the same day.

Food safety is the main reason to keep it cold. Plain cold brew is a low-acid drink. The US National Coffee Association notes that low-acid foods can, under some conditions, let pathogens grow, though its own challenge study found no pathogen growth in plain, unsweetened cold brew. In a hot kitchen, the simple rule is: brew it in the fridge, store it in the fridge, and throw it out if it smells sour or off.

How much caffeine is in cold brew?

There is no single number. Caffeine in a glass of cold brew depends on the beans, the ratio, the steep time and how much you dilute it.

• Ratio and dilution matter most. A 1:8 concentrate is very strong; once you mix it 1:1, it is closer to regular coffee strength. A 1:15 ready-to-drink batch is milder.
• Long steeps extract caffeine fully. A 2017 study by Fuller and Rao found caffeine in cold brew reached its peak after about 6 to 7 hours at room temperature, and that coarse-ground cold brew had more caffeine than hot brew made at the same ratio.
• Beans matter. Robusta has about twice the caffeine of Arabica. Kapeng barako (Liberica) is bold in flavour but its caffeine is similar to Arabica, not higher.

For reference, the US Food and Drug Administration says about 400 mg of caffeine a day is not generally associated with negative effects for most healthy adults. Concentrate is easy to over-pour, so measure it.

Is cold brew less acidic?

Cold brew tastes less acidic, but it is not lower in pH. A 2018 study by Rao and Fuller at Thomas Jefferson University, published in Scientific Reports, compared hot and cold brew from six coffees. The pH of all samples was similar, between 4.85 and 5.13. Hot brew had more titratable acids (which is why it tastes brighter and sharper) and higher antioxidant activity than cold brew.

So if you prefer cold brew because it tastes smoother, that is real. But it is not proven to be easier on the stomach or better for you than hot coffee. If you have a stomach condition, follow your doctor’s advice.

Best beans and grind for cold brew

Cold water pulls out less of the sharp, sour notes, so cold brew leans towards body, chocolate and caramel. Medium and dark roasts both work; choose based on how you drink it.

Grind: choose YES (COARSE GRIND) on any of our coffees; it is the same grind we use for French press. Or buy whole beans and grind just before brewing. Fine grounds make cold brew muddy, gritty and hard to filter. Not sure which coffee you like? Take our Coffee Match Quiz or request a free coffee sample. Cafés can buy any of these in 10 kg wholesale boxes.

Common cold brew mistakes and fixes

Cold brew drink ideas

• Condensed milk cold brew latte: 1 to 2 tablespoons condensed milk, 100 ml concentrate, 100 ml fresh milk, lots of ice. Robusta or barako is perfect here.
• Muscovado cold brew: sweeten with muscovado syrup (muscovado dissolved in equal hot water) for a caramel flavour.
• Coffee ice cubes: freeze diluted cold brew in an ice tray so your drink stays strong as it melts.
• Spiced cold brew: add a cinnamon stick or a few crushed cardamom pods to the grounds before steeping.

Frequently asked questions

What is the best ratio for cold brew coffee?

Use 1:8 coffee to water by weight for a concentrate that you dilute 1:1 with water or milk, or 1:12 to 1:15 for cold brew you drink straight. For 1 litre of water, that is 125 g of coffee for concentrate or 67 to 83 g for ready-to-drink.

How long should I steep cold brew?

Steep for 12 to 18 hours in the fridge. Start at 14 to 16 hours, then go shorter if it tastes bitter or longer if it tastes weak.

Should cold brew steep in the fridge or at room temperature?

In the Philippines we recommend the fridge. Room temperature is often around 30°C, and cold brew is a low-acid drink, so brewing and storing it cold is the safer choice and keeps the flavour cleaner.

How long does cold brew last in the fridge?

Drink ready-to-drink cold brew within about a week. Undiluted concentrate is commonly kept for up to about two weeks in a sealed container, but it tastes best in the first week. Finish it the same day once milk is added.

Is cold brew less acidic than hot coffee?

It tastes less acidic, but its pH is about the same. A 2018 Scientific Reports study found hot and cold brew both ranged from pH 4.85 to 5.13, while hot brew had more titratable acids and higher antioxidant activity.

What is the best coffee for cold brew?

For cold brew with milk, choose a bold dark roast such as Robusta or Kapeng Barako. For black cold brew, choose a smoother medium roast such as Benguet Arabica or CB’s Finest. Use a coarse grind.

References

• Rao, N.Z. & Fuller, M. (2018), Acidity and Antioxidant Activity of Cold Brew Coffee, Scientific Reports (pH, titratable acidity and antioxidants)
• Fuller, M. & Rao, N.Z. (2017), The Effect of Time, Roasting Temperature, and Grind Size on Caffeine and Chlorogenic Acid Concentrations in Cold Brew Coffee, Scientific Reports (caffeine extraction time)
• Corey, M. (2024), Cold brew coffee safety & compliance, Tea & Coffee Trade Journal (National Coffee Association on low-acid status and pathogen testing)
• US Food and Drug Administration, Spilling the Beans: How Much Caffeine is Too Much?

Last updated October 2, 2026.