Cold brew guide
Cold brew coffee, without the 18-hour wait
Cold brew is the smoothest way to drink coffee cold, and the slowest to make. Here is what it is, how it differs from iced coffee, and how to get a real glass of it in 5 seconds.
Updated October 2026
What is cold brew coffee?
Cold brew is coffee that is never heated. Ground coffee steeps in cold or room-temperature water for 12 to 24 hours, then the grounds are strained out. Hot water pulls bitter, sharp-tasting compounds out of coffee in minutes; cold water works slowly and gently, so the cup that comes out is smooth, rounded and naturally a little sweet, even with no sugar.
It is usually brewed strong, as a concentrate, and then diluted with water, milk or ice. That is why cold brew holds up in a glass of ice instead of tasting watery.
Cold brew vs iced coffee
They look the same in the glass. They are not the same drink.
| Cold brew | Iced coffee | |
|---|---|---|
| How it is made | Steeped cold for 12 to 24 hours | Brewed hot, then poured over ice |
| Taste | Smooth, mellow, less bitter | Sharper and more bitter, like hot coffee |
| Over ice | Brewed strong, so it stays full-flavoured | Gets diluted as the ice melts |
| Time to make at home | A day, plus straining | About 5 minutes |
Why most people don't make it at home
Cold brew is simple but slow. You need coarse-ground coffee, a jar, a day of waiting, a filter, and room in the fridge, and the batch only keeps for about a week or two before it tastes flat. If you want one glass on a hot afternoon, at the gym or on a trip, home brewing is no help.
Real cold brew in 5 seconds
A Cafe at Once Cold Brew tube is the brewing already done. It is real cold brew made from 100% Arabica coffee, sealed in a 16 g press tube with nitrogen instead of air, so it keeps for 12 months without a fridge and with nothing added: no sugar, no preservatives.
- 01Fill a glass with ice and 150 to 300 ml of cold water (less water for a bolder cup).
- 02Peel the tube open and squeeze the cold brew in.
- 03Stir once. That is it: no steeping, no straining, no machine.
The tube is small and sealed, so it goes in a gym bag, a desk drawer or a cabin bag. Read more on how nitrogen keeps coffee fresh.
Ways to drink it
| Drink | How |
|---|---|
| Black over ice | One tube, 150 to 300 ml cold water, a full glass of ice. |
| Cold brew with milk | One tube over ice, topped with cold milk or oat milk. |
| Cold brew tonic | One tube over ice, topped with tonic water. Bright and fizzy. |
| Hot | One tube in a mug of hot water or hot milk, when the weather turns. |
What does cold brew cost?
A café cold brew in India typically costs ₹280 to ₹460 a cup, and bottled cold coffee ₹85 to ₹150 for 200 to 250 ml. A Cafe at Once Cold Brew tube is ₹199 and makes one or two glasses. See the full comparison in our cold brew coffee price guide.
Questions people ask
- What is cold brew coffee?
- Cold brew is coffee made by steeping ground coffee in cold or room-temperature water for 12 to 24 hours instead of brewing it with hot water. The slow, cool extraction gives a smooth, rounder cup that tastes less bitter and less sharp than hot coffee.
- Is cold brew the same as iced coffee?
- No. Iced coffee is regular hot-brewed coffee poured over ice, so it keeps the bitterness and sharpness of hot coffee and gets watered down as the ice melts. Cold brew is brewed cold from the start, which is why it tastes smoother.
- Is cold brew stronger than regular coffee?
- It depends on how much you dilute it. Cold brew is usually made as a concentrate and then mixed with water, milk or ice. With Cafe at Once you choose the strength: one tube in about 150 ml makes a bold cup, in about 300 ml a lighter one.
- How do I make cold brew without waiting 24 hours?
- Use a cold brew concentrate that has already been brewed. A Cafe at Once Cold Brew tube is real brewed 100% Arabica cold brew sealed with nitrogen: squeeze it into 150 to 300 ml of cold water with ice, stir, and it is ready in about 5 seconds.
- Does cold brew need to be kept in the fridge?
- Home-made cold brew does, and it only keeps for about a week or two. Cafe at Once tubes are nitrogen-sealed, so they need no refrigeration and keep for 12 months unopened. Use a tube once you open it.
- Can I drink cold brew hot?
- Yes. A cold brew concentrate can be mixed with hot water or hot milk. It stays smooth, though most people prefer it over ice.