How to use the cold brew calculator
- Enter your water. Type how much water goes in the jar, in ml or fl oz. The coffee weight follows.
- Pick 1:5 or 1:4. 1:5 is the standard figure. 1:4 is the stronger end of the National Coffee Association's range.
- Choose a dilution and a glass. Pick strong (1:1) or mellow (1:2) and a glass size to see the concentrate and water for one glass.
Cold brew ratio
The sources give a narrow range, so the calculator offers just two settings: 1:5, the standard, and 1:4, the stronger end of the National Coffee Association's range.
| Water | Coffee at 1:5 | Coffee at 1:4 |
|---|---|---|
| 500 ml (16.9 fl oz) | 100 g | 125 g |
| 1000 ml (33.8 fl oz) | 200 g | 250 g |
| 1500 ml (50.7 fl oz) | 300 g | 375 g |
| 2000 ml (67.6 fl oz) | 400 g | 500 g |
Steep time
Cold steeping is slow. The sources give a window, not an exact time, so pick one length and keep it the same while you adjust the ratio.
| Steep time | What the source says | Source |
|---|---|---|
| About 12 hours, or overnight | The National Coffee Association's basic method (fridge or room temperature). | NCA |
| 12 to 18+ hours | The NCA says steeping can run from a few minutes to 12 to 18+ hours. | NCA |
| 12 to 24 hours | Wikipedia and Home Grounds give the 12 to 24 hour window. | Wikipedia, Home Grounds |
Grind size for cold brew
Coarse (NCA, Wikipedia). The National Coffee Association's rule is that the longer the water touches the coffee, the coarser the grind should be, and cold brew is the longest method. A grind that is too fine slows the strain and clouds the glass. Compare it with the other methods on the grind size chart, or check the coffee ratio calculator for the same method.
Diluting concentrate
A concentrate is meant to be mixed. Home Grounds suggests 1 part concentrate to 1 part water for a strong glass, or 1 to 2 for a mellow one. It is the only source we found for those figures, so taste and adjust.
| Taste | Concentrate : water | Per 250 ml glass | Source |
|---|---|---|---|
| Strong | 1:1 | 125 ml concentrate + 125 ml water | Home Grounds |
| Mellow | 1:2 | 83 ml concentrate + 167 ml water | Home Grounds |
Frequently asked questions
What is the best cold brew ratio?
The National Coffee Association gives 1 g of coffee to 4 to 5 g of water (1:4 to 1:5). Home Grounds calls 1:5 the standard. That is about 200 g of coffee for 1 litre of water. Start at 1:5 and move to 1:4 if you want it stronger.
How long should cold brew steep?
The National Coffee Association says about 12 hours or overnight, and that steeping can run 12 to 18 hours or more. Wikipedia and Home Grounds give 12 to 24 hours. Pick a time in that window and keep it the same while you adjust the ratio.
What grind is best for cold brew?
Coarse. The National Coffee Association and Wikipedia both say coarse-ground coffee for cold brew. The longer the water touches the coffee, the coarser the grind should be. See the grind size chart.
How do I dilute cold brew concentrate?
Home Grounds gives 1 part concentrate to 1 part water for a strong glass and 1 part concentrate to 2 parts water for a mellow one. The calculator works out the millilitres for your glass. That is one source, so treat it as a starting point and taste.
Should cold brew steep in the fridge or on the counter?
Either. The National Coffee Association says to let it steep in the refrigerator or at room temperature, covered. Wikipedia says the water is normally room temperature but chilled water can be used.
How much caffeine is in cold brew?
No figure here. USDA, the FDA and Harvard do not list cold brew, so the caffeine calculator leaves it out. A bottled cold brew may print caffeine on its label. The FDA cites about 400 mg a day as an amount not generally linked to negative effects for most healthy adults; ask your doctor about your own limit.
What do I need to make cold brew at home?
A jar or other container, coarse-ground coffee, cold or room-temperature water, and a way to strain it. The National Coffee Association lists cloth, metal and paper filters, and says to filter the grounds out before you drink it.
Link to this tool
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Gear that helps
This article reflects independent editorial research and disclosed buying criteria. This is not a substitute for your machine's manufacturer manual or professional service guidance. As an Amazon Associate, BaristaBetter earns from qualifying purchases (affiliate disclosure).
Cold brew makers
A jar with a built-in filter takes care of the straining.
See options on Amazon for Cold brew makersBurr coffee grinders
A burr grinder gives the even coarse grind cold brew wants.
See options on Amazon for Burr coffee grindersDigital coffee scales
Ratios are by weight, so a scale keeps every batch the same.
See options on Amazon for Digital coffee scales