How to Make Cold Brew Concentrate at Home (1:4 Ratio)

Quick answer: For a 1:4 cold-brew concentrate, combine 100 grams of coarsely ground coffee with 400 grams of water. Steep for 12 to 18 hours, filter, refrigerate, and start by diluting 1 part concentrate with 2 parts water or milk.

This is a concentrate recipe, not a ready-to-drink ratio. The word concentrate matters because the filtered coffee is intentionally strong and should be diluted before serving.

Cold-brew concentrate recipe

Ingredients

• 100 grams coarsely ground coffee
• 400 grams filtered water

Equipment

• Clean jar or covered brewing container
• Digital kitchen scale
• Spoon
• Fine-mesh strainer plus a paper coffee filter or clean cloth filter
• Clean covered container for refrigeration

Method

1. Weigh the coffee and water. Use 100 grams of coffee and 400 grams of water. That is a true 1:4 coffee-to-water ratio by weight.
2. Use a coarse grind. Aim for particles similar to coarse sea salt. Fine grounds are harder to filter and can make the cup taste harsh or silty.
3. Combine completely. Add the coffee and water to the brewing container. Stir gently until no dry pockets remain.
4. Steep covered at room temperature for 12 to 18 hours. A longer steep is not automatically better.
5. Filter without pressing the grounds. Strain once to remove the bulk of the grounds, then pass the concentrate through a paper or clean cloth filter if you want less sediment.
6. Refrigerate promptly. Transfer the concentrate to a clean, covered container and label the brew date.

Why use a 1:4 ratio?

A 1:4 ratio makes a strong concentrate in a small batch. It is not the only valid cold-brew ratio. Commercial systems and home recipes use different coffee doses, steep times, and dilution instructions.

If 1:4 is stronger than you want, brew at 1:5 or 1:6 instead. Keep the notation consistent: coffee first, water second.

How to dilute cold-brew concentrate

Start with 1 part concentrate to 2 parts water or milk. Taste it over ice, then add more concentrate if you want a stronger cup.

Ice melt changes the final strength, so treat these as starting measurements.

Which coffee works for cold brew?

Start with a coffee you already enjoy. Chocolate, caramel, nut, and fruit tasting notes can all work; they are natural impressions from the coffee, not added flavoring.

A medium or darker roast often produces a familiar, fuller cold-brew profile. A lighter fruit-forward coffee can produce a brighter result. Neither is universally better.

Grind immediately before brewing when possible. No particular origin or roast is required.

Is cold brew less acidic than hot coffee?

In a peer-reviewed comparison of coffees brewed hot and cold at the same coffee-to-water ratio, the pH values were comparable. The hot brews had more total titratable acids.

That means cold brew may taste less sharp in some comparisons, but pH, perceived acidity, roast, coffee, water, ratio, and recipe are not interchangeable. Cold brew should not be presented as a guaranteed low-acid solution for a medical condition or sensitive stomach.

How much caffeine is in cold-brew concentrate?

There is no reliable universal number. Coffee, dose, grind, steep time, final yield, and dilution all affect the cup. Because this recipe uses a high coffee dose and produces concentrate, do not drink it as though it were ready-to-drink coffee.

The U.S. Food and Drug Administration cites 400 milligrams of caffeine per day as an amount not generally associated with negative effects for most adults, while noting that sensitivity varies. If caffeine affects you strongly, use a smaller serving. Decaf contains less caffeine than regular coffee, but it still contains some.

How long does homemade concentrate last?

Keep it covered and refrigerated. Toddy's instructions state that concentrate made in its system can stay fresh for up to two weeks in the refrigerator. This simple jar recipe does not claim the same shelf life, so make a small batch and plan to use it within about a week.

Homemade concentrate requires refrigeration. Discard it if you see mold or notice an unexpected fermented or otherwise off smell.

Troubleshooting

Why does it taste bitter or harsh?

The grind may be too fine, the steep may be too long, the coffee may be too dark for your preference, or the concentrate may need more dilution. Change one variable at a time.

Why does it taste weak?

Confirm that you measured by weight and used 100 grams of coffee to 400 grams of water. Check for dry pockets, use a consistent steep time, and reduce dilution before changing the recipe.

Why is it cloudy or silty?

Use a coarser grind and finish with a paper filter. Avoid squeezing or pressing the grounds during filtration.

Frequently asked questions

Can I use pre-ground coffee?

Yes, if it is ground coarsely enough for cold brew. Standard fine pre-ground coffee is harder to filter and may taste harsher.

Can I steep it in the refrigerator?

Yes. Extraction is slower when cold, so begin near the longer end of the steeping range and adjust after tasting the filtered, diluted coffee.

Do I need a special cold-brew maker?

No. A clean jar, scale, and suitable filter are enough for this small-batch method.

Can I drink the concentrate without diluting it?

You can taste it, but the recipe is designed for dilution. Start with 1 part concentrate and 2 parts water or milk.

Sources

• Scientific Reports: Acidity and Antioxidant Activity of Cold Brew Coffee
• Toddy Cold Brew System: official concentrate instructions
• U.S. Food and Drug Administration: Spilling the Beans—How Much Caffeine Is Too Much?

Choose coffee for your cold brew

Use the flavor profile you want, then keep the ratio, grind, and steep time consistent enough to repeat it.

For the next adjustment, read the cold-brew grind-size guide. When you are ready to choose a coffee for the recipe, browse the current coffee collection.