Cold Brew Method: Ratios, Grind, Filtration and Storage

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What Is Cold Brew?

Cold brew is coffee extracted with cool water, then separated from the grounds. This page focuses on immersion: the grounds stay in the water during the steep. Cold drip moves water slowly through a coffee bed instead.

Concentrate and ready-to-drink describe how the filtered coffee will be served. Concentrate needs a dilution plan; a lighter batch may be suitable to drink as it is. Use the complete recipe below for a fridge batch. The cold brew drink guide covers serving styles; this guide explains equipment, scaling, extraction and filtration.

Cold Brew Ratio, Grind Size, and Brew Time

Write the ratio as dry coffee mass to brewing-water mass. For 1:9, divide the water weight by nine to find the coffee dose: 720 g (24.3 US fl oz) water needs 80 g coffee.

The National Coffee Association's reference method specifies 1 g coffee to 4–5 g water and roughly 12 hours of contact. Our home recipe is a separate 1:9, 16-hour refrigerated starting point. Do not transfer a concentrate's dilution instructions to that lighter batch.

The calculator uses 1:4, 1:6 and 1:9 presets. It scales input weights, not recovered liquid or servings. Check that the wet grounds fit the brewer and that the water can reach them; a narrow filter basket can limit the usable dose before the pitcher is full.

Reader Tool

Cold Brew Batch Calculator

RatioGrindDilution

Editorial starting presets, measured by mass. This tool calculates coffee for the water you add. Measure the filtered coffee separately: grounds retain water, and serving size depends on dilution. Check your container and filter capacity before scaling up.

Batch waterReset

g

250 g3000 g

Water in grams. Decimals are welcome.

500 g750 g1000 g1500 g

Brew style

Concentrate1:4Brew strong now and dilute later. Most flexible.Medium concentrate1:6Still concentrated, but easier to serve. Easy to adjust.Lighter brew1:9A lighter starting brew to taste before dilution. Least fuss.

Target batch

Simple 1:9 cold brew.

Input amounts

Recipe

Coffee

111.1 g

Water

1000 g

Steep

16 hr starting point

Ratio

1:9

Coffee: 111.1 gWater: 1000 g (33.8 US fl oz)Coffee amounts rounded to 0.1g. Ratio uses water added, not finished drink.

Brew note: Medium-coarse. Cover and steep in the refrigerator at 4°C / 40°F or below. Filter after the starting steep and keep the finished coffee covered and refrigerated.

Serving: Taste the filtered coffee first; add water or milk if needed and allow for ice melt.

Best for: Simple fridge coffee and black iced cups.

Next steps

1. 1. Stir until every dry pocket is wet.
2. 2. Start with 16 hours in the fridge; assess flavor after filtering and dilution.
3. 3. Filter well and adjust strength in the glass.

Grind and Steep Adjustments

Start coarse to medium-coarse, with grounds you can strain without excessive sediment. Extremely coarse pieces can give weak extraction; abundant fines can slow paper filtration. Record the grinder setting along with the recipe.

Espresso-fine coffee is not the easiest choice for this coarse-ground recipe. If you have already steeped a fine-ground batch, strain loose grounds through mesh before the paper stage, then let small portions drain without squeezing or forcing the filter. Keep the batch refrigerated during handling. For the next batch, choose a coarser grind rather than trying to compensate by extending every steep.

For a repeatable home trial, use the linked recipe's 16 hours at 4°C / 40°F or colder. Keep temperature and dose fixed while changing grind or steep time on the next batch. Extending every weak batch does not fix dry pockets, an incorrect dose or excessive water added in the glass.

When comparing steep times, I bring the samples to the same drinking strength. Otherwise I'm too easily drawn to the more concentrated cup, even when I don't enjoy its balance as much once it's diluted.

How to Make Cold Brew at Home

This is the same refrigerated batch as the cold brew drink recipe. Allow extra time if paper filtration runs slowly.

Recipe

Refrigerated Cold Brew

Makes:

1 filtered batch; weigh the recovered yield

Time:

16 hours steeping + about 10 minutes active work; filtering may take longer

Print recipe

Ingredients

• 80 g medium-coarse ground coffee
• 720 g (24.3 US fl oz) cold drinking water
• Ice, optional, added after measuring each serving

Equipment

• Covered food-safe jar or pitcher (at least 1 litre / 34 US fl oz)
• Kitchen scales and spoon
• Mesh strainer and supported paper coffee filter
• Clean receiver and covered storage container
• Refrigerator thermometer
• Serving glass

Method

1. Combine. Put 80 g medium-coarse coffee and 720 g (24.3 US fl oz) cold drinking water in the clean jar or pitcher. Stir until all the grounds are wet, cover and mark the brew-start date.
2. Refrigerate. Steep for 16 hours at 4°C (40°F) or colder.
3. Filter and weigh. Strain into a clean receiver, then pass through a rinsed paper coffee filter in a supported holder. Weigh the collected coffee, subtracting the receiver’s weight; the grounds retain some water.
4. Serve. Measure 240 g (8.5 oz) filtered coffee into a glass. Taste before adding optional ice or water.
5. Store. Refrigerate the remaining plain coffee in a clean covered container at 4°C (40°F) or colder. Use within a few days, with day seven as the outer limit, counting the brew-start day as day one.

For example, if you collect 600 g (21.2 oz), you can pour two 240 g (8.5 oz) servings with 120 g (4.2 oz) left over. Use your measured batch weight for this calculation, and check vessel and filter capacity before scaling up.

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Home Cold Brew Setup

A jar, a French press or a dedicated pitcher can provide the immersion vessel. A scale and a reliable filter make the routine easier to repeat. Choose equipment you can clean thoroughly and fit in the refrigerator.

The coffee filters guide explains material and care. A loose mesh passing sediment is a filtration issue, not proof that the coffee steeped too long. Avoid squeezing grounds through paper to recover an assumed target yield.

Cold Brew Troubleshooting

Check the undiluted filtered batch, then the finished serving. That separates an extraction problem from a dilution problem.

Storage and Serving Ideas

Brew and store the home batch covered at 4°C / 40°F or colder. Use clean food-safe equipment and drinking water; add milk and sweeteners to individual servings. Aim to finish within a few days. For this workflow, do not keep it beyond day seven, counting the brew-start day as day one.

Why this guide uses a refrigerated seven-day limit

That outer limit is a cautious adaptation of Wisconsin DATCP's retail guidance: brewing, holding and serving at 41°F or below, with date marking for no more than seven days. It applies to retail establishments and does not validate every home batch or guarantee safety until day seven. The FDA's home guidance supplies the stricter 40°F refrigerator target. Follow commercial packaging instructions for purchased coffee.

Discard coffee with suspicious growth, gas or odor. Tasting cannot establish that a mishandled batch is safe.

How Much Water Should You Add to Concentrate?

For OXO's compact-brewer concentrate, add 120–180 ml (4–6 US fl oz) water or milk to 60 ml (2 US fl oz) concentrate, following its instructions. That 1:2 to 1:3 serving-volume ratio belongs to that concentrate, not the lighter 1:9 home batch or the dry-coffee-to-brewing-water calculation.

For your own batch, weigh a small portion and add measured water until you like it. 100 g (3.5 oz) filtered coffee plus 100 g (3.4 US fl oz) water makes 200 g (7.1 oz) of drink with the original portion's total caffeine. Replacing half the coffee in a fixed-size serving with water is different: it uses half as much of that batch. Ice melt adds further water.

Caffeine, Calories and Sugar

Starbucks lists approximately 205 mg caffeine, 5 kcal and 0 g sugar for its plain US Grande Cold Brew, 473 ml (16 US fl oz). This named café serving is a comparison; the home recipe's caffeine is unmeasured.

Serving assumptions and sources

The café reference is coffee and ice without added milk or syrup. Its volume is not a conversion from the home recipe's weighed serving. Beans, dose, extraction, recovered yield and dilution change the caffeine concentration. The plain home recipe has no added sugar; count milk, cream and sweeteners separately from their actual amounts and labels.

What Does Cold Brew Taste Like?

A medium roast with cocoa and nut notes makes an easy, mellow starting point; a lighter, fruitier coffee can leave a brighter finish, and a dark roast can stay firmly bitter. The brewing and serving choices determine whether those flavors feel full or thin.

Filtration changes the texture. Mesh-filtered coffee may feel heavier and leave some fine sediment; a paper-filtered cup feels cleaner. Dilution changes intensity too, so judge a concentrate after bringing it to a strength you enjoy rather than expecting it to drink like finished black coffee.

I prefer paper-filtered cold brew for drinking black because a cleaner sip lets me notice the coffee’s sweetness without grit distracting from it.

Perceived sharpness and measured acidity describe different aspects of coffee. A 2018 study of six coffees found comparable pH values in its hot and cold brews, while the hot samples had higher titratable acidity, a different measure of the acids present.

Best Beans for Cold Brew

Start with flavors you already enjoy. A medium roast is a practical first trial; lighter or darker coffee can work too. Choose a chocolate-leaning profile if that suits your milk drink, or fruit notes if you want to explore them black.

Use suitable pre-ground coffee if needed, keeping the dose and brew record consistent. There is no required species of “cold brew bean.” Choosing coffee beans gives broader buying context.

Cold Brew vs. Iced Coffee

Choose immersion cold brew when making coffee ahead suits your routine. Choose Japanese iced coffee when you want hot extraction followed by immediate chilling. It takes minutes rather than an overnight steep.

For a short, concentrated cold coffee, choose between cold-brew concentrate and iced espresso. The first is extracted in cool water; the second starts with a hot, pressure-brewed shot. Beans sold for espresso can also be cold-brewed.

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A Mizudashi pitcher is a particular immersion setup. New Orleans-style cold brew adds a chicory tradition, while nitro concerns gas and serving equipment. Keep their preparation requirements separate from an ordinary home jar.

The Toddy Brewer and Cold-Brew Concentrate

The Toddy brewer is a useful landmark in the history of immersion cold brew. Its 2022 brewing guide dates the Classic method to 1964: grounds steep in a container with a felt filter, then removing a stopper lets the concentrated coffee drain into a glass decanter.

The concentrate was never limited to iced drinks. Toddy’s guide also describes mixing it with steaming water for hot coffee. That distinction still matters: cold brew names the extraction method, while the finished cup can be hot or cold. For the later bottled-coffee story, see cold brew coffee.

Common Questions Before You Brew

Can I Steep Cold Brew at Room Temperature?

Some published methods do, including NCA's reference. The home workflow here uses continuous refrigeration. Do not change to a warm countertop while retaining the same handling assumptions.

Is a 1:4 Cold Brew Ratio Always Concentrate and 1:9 Always Ready to Drink?

They are useful starting labels, not strength measurements. Taste a measured filtered portion and record the serving dilution.

Can I Make Cold Brew in a French Press?

Yes, if the covered setup fits your refrigerator and allows the grounds to stay wet. Strain after steeping instead of storing the finished brew on the grounds. Additional paper filtration can reduce sediment.

Editor's Take

Sources and Further Reading

View 8 references

Method and equipment

• National Coffee AssociationCold brew methodNational Coffee Association · Method, coarse starting grind and explicitly mass-based 1:4–1:5 reference(opens in a new tab)
• OXOCompact cold-brew instructionsOXO · Serving dilution for the named OXO concentrate(opens in a new tab)
• ToddyCold Brew System Home Model brewing guideToddy · Coarse-grind recommendation and method-specific filter handling(opens in a new tab)

Method comparison

• National Coffee AssociationEspresso definitionNational Coffee Association · Espresso is defined by its hot pressure-brewing method, not a bean or roast label(opens in a new tab)

Research

• Rao and Fuller, Scientific ReportsAcidity and antioxidant studyRao and Fuller, Scientific Reports · Six-coffee experiment distinguishing pH and titratable acidity(opens in a new tab)

Storage

• Wisconsin DATCPCold brew fact sheetPDFWisconsin DATCP · Retail refrigeration and date-marking guidance, explicitly scoped(opens in a new tab)
• U.S. FDAAre you storing food safely?U.S. FDA · Home refrigerator temperature and handling guidance(opens in a new tab)

Serving reference

• StarbucksUS Cold Brew nutritionStarbucks · Plain US Grande Cold Brew serving, 16 US fl oz(opens in a new tab)