Cold steep · Iced
Cold brew coffee recipes
Cold brew trades heat for time.
- Coffee
- 60 g
- Water
- 900 g
- Temp
- 20 °C
- Time
- 12 h
Instead of a few minutes in hot water, coarse coffee sits in room-temperature water for half a day, and you filter it afterwards. This page gives two builds because they answer different needs. The ready-to-drink jar makes 900 g of water into about three glasses and is for people who want to pour and drink. The concentrate uses far more coffee for the same water, keeps in a smaller space, and is for people who dilute to taste and want several drinks from one jar. To work out your own batch size, open the cold brew calculator.
The two builds
| Part | Ready to drink | Concentrate |
|---|---|---|
| Coffee | 60 g, coarse | 100 g, coarse |
| Water | 900 g (1:15) | 500 g (1:5) |
| Temperature | 20 °C | 20 °C |
| Steep | 12 h | 14 h |
| Serves | about 3 | about 4 once diluted |
You need
- A lidded jar, a coarse filter or sieve and a paper filter for the second pass.
- A scale, a refrigerator and a clean bottle for storage.
Ratio 1:15 · Grind: coarse · grind chart
Starting ranges come from your grinder maker’s own guide. Burrs, beans and calibration vary, so treat them as where to begin.
Steps
- 0:00, Combine coffee and water.
Add the coffee, pour in the water and stir until no dry grounds remain. This takes about a minute.
- 1:00, Steep covered.
Leave the jar closed. The ready build steeps for twelve hours, the concentrate for fourteen.
When the steep ends, pour through a sieve, then slowly through paper if you want a clear result. Chill promptly. Dilute the concentrate by weighing, not by guessing glass size.
My notes for this recipe
Why these numbers
Coarse grind. Hours of contact do the extraction work, so you can trade surface area for a cleaner, easier-to-filter bed. The grind chart gives the planning range.
1:15 for the drinkable build. It sits among the pour-over ratios on this site, 1:15 to 1:16.7, so the result is drinkable without dilution. Authored.
1:5 for the concentrate. One part coffee to five parts water is far stronger. Grounds keep water, so you will recover less liquid than the 500 g you poured. Using the calculator's 2 g/g absorption planning assumption, 100 g of coffee holds about 200 g, leaving roughly 300 g of liquid. Adding about 1,000 g of water then gives about 1,300 g, which is the same liquid per gram of coffee as the ready build (900 g minus about 120 g retained, giving 780 g from 60 g). That ignores any difference in extraction between the two jars.
12 and 14 hours. Authored. The longer concentrate time compensates for the denser slurry; neither is a measured optimum.
What changes the cup: time, temperature and storage
Temperature and time trade against each other. A jar left in the refrigerator extracts differently from one on the counter, so one twelve-hour figure cannot suit both. Use 20 °C for this recipe as written and treat any other place as a new experiment.
- Thin, sour cup after twelve hours. Extend by two hours next time, or grind a little finer.
- Muddy or bitter cup. Shorten the steep, or filter more thoroughly. Over-long steeps of fine grounds tend to taste harsh.
- Cloudy. A second pass through paper removes most fines, slowly.
- Storage. Refrigerate promptly once filtered. Keep the bottle closed and use a clean container.
Those fixes are CupTune's judgement from how immersion behaves, not results of a tested cold-brew trial.
Evidence and limits
SCA cold-brew research found different extraction behaviour at 4, 22 and 92 °C and across origin and roast. The 20 °C, twelve-hour recipe is therefore only a starting point. FDA storage guidance says to refrigerate prepared food within two hours and keep a refrigerator at or below 40 °F (4 °C); CupTune makes no shelf-life prediction. The dilution arithmetic rests on an assumption that real grounds will not match exactly.
Questions
Should the jar steep in the refrigerator?
The SCA research suggests extraction differs at 4 and 22 °C, so a fridge steep likely needs longer than the 12 hours given here. CupTune does not provide a tested fridge figure.
How do I dilute the concentrate?
Weigh the concentrate, add water by weight, and taste. Start at roughly three parts added water for every one of concentrate and adjust.
How long does it last?
CupTune cannot predict shelf life. Follow the FDA guidance above and discard anything that smells or looks off.