Batch size before guesswork
Size coffee and water to the vessel, then treat retained water and serving dilution as explicit estimates.
Approximate batch
Actual yield depends on grinder, filter, squeeze and retention. Weigh it rather than assuming.
Serving a 1:5 concentrate
Cold brew concentrate brewed at 1:5 is usually served cut with water. Mixed 1 part concentrate to 2 parts water by weight, a 300 g glass takes 100 g concentrate and 200 g water and keeps about 33% of the concentrate's strength. Start at 1 : 1 if you pour it over ice, because melting ice adds water the table does not count.
| Mix | Strength | Concentrate | Water | Overall |
|---|---|---|---|---|
| Undiluted | 100% | 300 g | 0 g | 1:5 |
| 1 : 1 | 50% | 150 g | 150 g | 1:8 |
| 1 : 2 | 33% | 100 g | 200 g | 1:11 |
| 1 : 3 | 25% | 75 g | 225 g | 1:14 |
Mix is concentrate : water by weight. Strength is the share of the concentrate's dissolved coffee left after mixing, 1 ÷ (1 + parts of water). Overall is grams of water per gram of coffee, counting the serving water with the brew water and using CupTune's editable planning assumption that the grounds keep 2 g of water per gram of coffee. Weights, not volumes: 1 g of water is about 1 ml.
The 1 : 3 row lands near the 1:15 ready-to-drink batch the calculator above starts from, so diluting a concentrate and brewing ready to drink end up in the same place. Taste and change one part at a time.
Measure concentrate and its current TDS, then choose a lower target. CupTune uses mass balance: final mass = concentrate × current TDS ÷ target TDS.
Open the cold brew recipes and handling guide.
SCA cold-brew research found that extraction behaviour varied with temperature, coffee origin and roast, so the calculator does not promise one steep result.
FDA storage guidance says to refrigerate prepared food promptly, within two hours, and keep a refrigerator at or below 40 °F (4 °C). CupTune does not assess microbial safety or shelf life.
CupTune starts ready-to-drink batches near 1:15 and concentrates near 1:5. Both are starting ranges, and grind and steep time move the result considerably.
Commonly eight to twenty-four hours, at refrigerator or room temperature. SCA research found extraction behaviour varying with temperature, origin and roast, so no single steep time is promised here.
Grounds retain water, and how much depends on grind, filter and how hard you squeeze. CupTune shows an approximate beverage figure and asks you to weigh the real one.
By mass balance: final mass equals concentrate mass times current TDS divided by target TDS. That needs a measured TDS rather than a guess about strength.