Coffee Drink
Cold Brew Coffee: Recipe, Ratios and How to Serve It
Make smooth immersion cold brew with a measured 1:9 recipe. Compare concentrate ratios, choose a steep time, filter clearly, dilute correctly and store it safely.
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What Is Cold Brew Coffee?
Cold brew is coffee extracted with cool water over several hours and then filtered. This ready-to-drink recipe uses 80 g coffee and 720 g water, a 1:9 coffee-to-water ratio by mass, with a 16-hour refrigerated steep. Concentrate recipes use less water and must be diluted to taste before serving.
Key Takeaways
- 1Use 1:9 for a practical ready-to-drink batch, or choose 1:4 to 1:6 when you specifically want concentrate.
- 2Start a 1:9 batch at 16 hours in the refrigerator; extending the steep is not the best way to fix weak coffee.
- 3Filter through mesh and then paper, then weigh the recovered batch before defining serving size or per-serving nutrition.
- 4Keep homemade cold brew covered at 4 C (40 F) or colder and use it within 7 days.
Cold Brew at a Glance
- Coffee
- 80 g
- Water
- 720 g
- Ratio
- 1:9 by mass
- Steep
- 16 hours
- Grind
- Medium-coarse
- Yield
- Weigh after filtering
Cold Brew Ratio Guide
The word cold brew covers both concentrate and ready-to-drink coffee. Decide which one you are making before measuring the ingredients.
This table scrolls horizontally on smaller screens.
| Style | Coffee | Water | Starting steep | How to serve |
|---|---|---|---|---|
| Strong concentrate | 100 g | 400 g | 14-18 hours | Start with equal parts concentrate and water or milk |
| Medium concentrate | 100 g | 600 g | 14-18 hours | Start with 2 parts concentrate to 1 part water or milk |
| Ready to drink | 80 g | 720 g | 16 hours | Taste first; little or no dilution may be needed |
These are repeatable house starting points, not universal cafe standards. Roast, grind, water, agitation and filtration all change the result. Keep the ratio fixed while dialing in so you can identify what each adjustment does.
How to Make Cold Brew Coffee
- Measure and combine. Add 80 g medium-coarse coffee and 720 g cold filtered water to a clean container. Stir only enough to wet all the grounds.
- Steep cold. Cover and refrigerate at 4 C (40 F) or colder for 16 hours.
- Filter in two stages. Use a fine mesh strainer to remove large particles, then a rinsed paper filter to reduce fine sediment.
- Taste before diluting. Pour over ice. If it is stronger than you want, add water or milk in measured 15-30 g steps.
- Measure and store. Weigh the filtered batch, record that recovered yield and refrigerate it in a clean covered container. Use it within 7 days.
The liquid yield will be lower than the 800 g of ingredients because coffee grounds retain water. Filtration method and grind size also change how much finished drink you collect. Do not assign a serving count from the input weight: record the filtered yield, choose a serving mass, and divide the first by the second.
Grind, Steep Time and Temperature
A medium-coarse grind gives water access to the coffee while remaining practical to filter. If the brew tastes thin at 16 hours, first verify the ratio and grind consistency. A slightly finer grind usually changes extraction more predictably than adding many more hours. If the cup is woody, harsh or muddy, use a slightly coarser grind, reduce agitation and improve filtration.
Cold-brew research shows that time, roast and grind all influence extraction. It does not support one universal steep time for every coffee. The 16-hour refrigerated baseline is a controlled place to start, not a claim that every batch peaks at exactly 16 hours.
Concentrate, Ready-to-Drink and Kyoto Slow Drip
Immersion cold brew keeps coffee and water together for the entire steep. Kyoto-style slow drip is a different method: water passes through a coffee bed gradually instead of soaking with it in one vessel. Both can be served cold, but they use different equipment, flow and recipe logic.
Concentrate is also not automatically stronger in the cup. A 1:4 batch can become mild after heavy dilution, while a 1:9 batch served undiluted can taste more intense. Record both the brewing ratio and the final dilution.
Flavor, Acidity, Calories and Caffeine
Cold brew often tastes round, chocolatey and less sharply acidic than the same coffee served as hot-brewed iced coffee. That is a sensory tendency, not a chemical guarantee. Perceived sourness, pH and titratable acidity describe different things, and controlled studies show that roast and recipe matter.
Plain cold brew made only with coffee and water is low in calories, but this batch does not carry a per-serving calorie figure because the filtered yield and serving mass have not been fixed. For repeatable portions, weigh the recovered batch and choose a serving mass before calculating any per-serving value. Calculate milk, cream, syrup or other additions separately from their measured amounts and labels.
Caffeine cannot be calculated from steep time, brew ratio, total dissolved solids or flavor strength. Species, dry dose, grind and extraction all contribute. If a tested batch contains C mg caffeine per 100 g and the serving weighs S g, the serving contains C x S / 100 mg. Without a measured concentration, this recipe should not claim an exact caffeine value.
Troubleshooting Cold Brew
This table scrolls horizontally on smaller screens.
| Problem | Likely cause | First adjustment |
|---|---|---|
| Weak or hollow | Too much water, very coarse grind or insufficient extraction | Confirm the 1:9 ratio, then grind slightly finer |
| Harsh or woody | Too fine, excessive agitation or overextended steep | Grind coarser and return to 16 hours |
| Muddy texture | Fine sediment passing through | Add a rinsed paper-filtration stage |
| Cloudy appearance | Fine particles or natural coffee oils | Paper-filter if clarity matters; cloudiness alone is not a safety test |
| Watery over ice | Too little coffee for the final dilution | Use more cold brew, larger ice or a concentrate recipe |
Storage and Food Safety
Cold brew is not shelf-stable simply because it is coffee. Use clean equipment, keep the covered brew and filtered drink at 4 C (40 F) or colder, and discard it if refrigeration has been interrupted or it develops an unexpected odor, gas, mold or texture. The 7-day home guideline is a conservative ceiling for this home workflow; commercial products rely on validated processing and should follow their own label instructions.
Questions About Cold Brew Coffee
Can I Steep Cold Brew at Room Temperature?
Refrigerated extraction gives a simpler safety control for a home recipe. If you use another method, follow a validated recipe and chill the filtered drink promptly.
Is Cold Brew the Same as Iced Coffee?
No. Cold brew is extracted with cool water. Conventional iced coffee and Japanese iced coffee are brewed hot and then chilled.
Should I Dilute Cold Brew Concentrate Before Storing It?
Either approach can work. Keeping concentrate undiluted saves space, but record the intended serving dilution so each cup is consistent.
Can I Warm Cold Brew?
Yes. Cold brew describes the extraction method, not a required serving temperature. Warm it gently and avoid prolonged holding.
Research Notes and Sources
Our ratio table separates ready-to-drink coffee from concentrate, and the safety guidance uses conservative refrigerated handling rather than treating coffee as self-preserving. Useful references include the controlled immersion sensory study, research on cold-brew acidity and time, roast and grind, plus food-safety guidance from Wisconsin DATCP and the Canadian Food Inspection Agency.