Cold brew is coffee steeped in cold water for hours. It never touches heat, and that's where everything else comes from: it's sweeter, less acidic, and smoother than any hot coffee chilled afterward.
Making it at home is one of the easiest methods. All it asks for is time.
Cold brew is not iced coffee
They are constantly confused and are distinct things.
Iced coffee is brewed hot and then cooled. It retains the acidity of hot coffee and will dilute as the ice melts.
Cold brew is extracted cold from the start. Cold water dissolves fewer acids and fewer bitter compounds, so the cup turns out well-rounded and sweet, with a denser body.
It's not that cold brew "has no acidity": it has less, and what it does have is perceived differently.
The confusion about proportions
If you search for recipes, you'll find everything from 1:6 to 1:15, and all claim to be correct. The explanation is simple: not all prepare the same thing.
Concentrate · 1:6 to 1:8
This results in a concentrate that is diluted when served, usually 50% with water, milk, or ice. It takes up little space in the fridge, lasts longer, and is what coffee shops do.
Ready-to-drink · 1:12 to 1:15
This is directly drinkable. More convenient if you're going to drink it within a couple of days, but it takes up the entire pitcher.
Start with 1:8 concentrate. With 125 g of coffee and 1 liter of water, you'll have enough for the whole week, and you can adjust the dilution cup by cup until you find your sweet spot.
Step-by-step recipe
What you need
- 125 g coarsely ground coffee
- 1 liter of filtered water at room temperature
- A jar or pitcher with a lid
- Paper filter, cloth, or a fine sieve with cheesecloth
Preparation
- Grind coarsely. Like coarse salt. If you grind finely, the coffee will over-extract in so many hours and turn out bitter and cloudy.
- Wet all the coffee. Add the water slowly and stir to prevent dry clumps. Coffee that doesn't get wet doesn't contribute anything.
- Steep for 12 to 18 hours. At room temperature, it extracts faster; in the fridge, slower and cleaner. Twelve hours yields a smooth cup; eighteen, a more intense one. After 24 hours, it starts to get bitter.
- Filter without pressing. First strain through a sieve, then through paper or cloth. Do not squeeze the grounds: that's precisely what brings bitterness and cloudiness.
- Store in the fridge. In a sealed container.
How to serve it
Concentrate and water in equal parts over ice. Or concentrate and cold milk, in a 40:60 ratio, for something sweeter. Taste before sweetening: cold brew is already sweet on its own.
If you're in a hurry: the Japanese method
It's called flash brew and makes cold coffee in five minutes, not twelve hours.
You prepare a normal filter coffee —V60, Chemex, drip coffee maker— but replace 40% of the water with ice in the carafe. For 30 g of coffee: 300 ml of hot water and 200 g of ice underneath.
The coffee falls hot onto the ice and cools down instantly. This locks in volatile aromas that would be lost in a long cold brew, making it more aromatic and acidic. It's not cold brew, it's something else, and many people like it more.
What coffee to use
Natural roast, medium or medium-dark. Very light roasts fall short when cold and taste flat; very dark ones bring burnt notes that long extraction accentuates.
Fresh coffee. Six to eight weeks after roasting, coffee has lost much of its aromas, and cold extraction won't recover them.
Ground at the moment, if you can. If you buy pre-ground, ask for a coarse French press grind.
From our range, the 100% Arabica Coffee makes a clean cold brew with a nutty and chocolate background. The Organic Coffee, is somewhat more citrusy. And the Arabica Blend Coffee, with its 20% robusta, comes out denser and with more body: it's the one that best holds up to milk.
How long does it last
The concentrate lasts 10 to 14 days in the fridge, well-sealed. The already diluted, 3 to 5 days: water makes it more perishable.
If you've diluted it with milk, treat it like milk: two days at most.
You'll know it's gone bad because it loses its sweetness and an acidic point appears.
Caffeine: the nuance
It's often repeated that cold brew has more caffeine, and that's half true.
The concentrate does have more per milliliter because it has much more coffee per water. But once diluted, a cup of cold brew has similar caffeine to a normal filter coffee.
What does change is how it feels: being less acidic and smoother, it's easy to drink more without realizing it.
If something goes wrong
Bitter. Too fine a grind, too many hours, or you squeezed the grounds when filtering.
Watery or flavorless. Not enough coffee, too coarse a grind, or less than 12 hours. Go up to 1:6 or extend to 18 hours.
Cloudy. A second filtering with paper is needed.
Acidic or astringent. Coffee too light for this method, or very hard water. Try with filtered water.
Cold brew tea
The same principle works with tea, and very few people know it.
Put 10 g of loose leaf tea per liter of cold water and leave it for 6 to 8 hours in the fridge. Without heat, tannins are not released, so it won't get bitter no matter how long you leave it: you can forget about it all night.
The best ones are the Original Green Tea, very fresh and floral when cold; the Red Silhouette Tea, fruity and designed to be drunk iced; and the Forest Fruit Infusion, which, being caffeine-free, can be drunk at any time.
Is it worth making at home?
One liter of concentrate comes from 125 g of coffee. With a 250 g package, you make two liters, which yields about sixteen cups once diluted.
Compared to the cost of a cold brew at a coffee shop, the difference is one to two. And the only real work is five minutes: the rest is done by time while you sleep.