How to Make Cold Brew Coffee Concentrate at Home
Table of Contents
- Cold Brew Coffee Concentrate Ratio: Getting the Numbers Right
- Best Coffee Grind for Cold Brew (and Which Beans to Use)
- How to Make Cold Brew Coffee Concentrate at Home: Step by Step
- How Long to Steep Cold Brew Concentrate (Room Temp vs Fridge)
- How to Dilute Cold Brew Concentrate for Iced Coffee
- Storing Cold Brew Concentrate: Shelf Life and Food Safety
- Troubleshooting Weak, Bitter, or Cloudy Cold Brew Concentrate
- Frequently Asked Questions
Last Updated: October 14, 2026
Cold Brew Coffee Concentrate Ratio: Getting the Numbers Right
Cold brew coffee is the drink you get when you soak coarse grounds in cold water for hours, then strain. A concentrate is that same brew made extra strong, so you add water or milk before serving. The ratio is what makes it work.
The standard starting point is 1:4 by weight. That's one part coffee to four parts water. For a small batch, weigh 100 g of coarsely ground coffee and pour in 400 g of cold filtered water.
Why weight and not scoops? Because volume lies. A scoop of fine grounds and a scoop of coarse grounds weigh different amounts. A kitchen scale fixes that in seconds.
Here's a quick conversion chart:
| Batch Size | Coffee (by weight) | Water (by weight) | Approx. Yield |
|---|---|---|---|
| Small | 100 g | 400 g | 300 ml concentrate |
| Medium | 200 g | 800 g | 600 ml concentrate |
| Large | 400 g | 1.6 kg | 1.2 L concentrate |
If you only have measuring cups, use 1 cup of coarse grounds to 4 cups of cold water. It's less exact, but it works.
Best Coffee Grind for Cold Brew (and Which Beans to Use)
The best grind for cold brew is coarse, about the texture of raw sugar or coarse sea salt. Fine grounds slip through filters and turn your concentrate muddy. Coarse grounds give you clean, smooth flavour.
Bean choice matters just as much. A dark roast brings chocolate and caramel notes that hold up well against ice and milk. A medium roast keeps more brightness and floral character.
At CuppaCrave, our Cold Brew Coffee is a dark French roast blended specifically for cold brewing, with very coarse grounds straight out of the bag. If you prefer something smoother, our medium cold brew blend brings chocolate, toffee and floral tones that work well for cold brew or nitro.
Two rules for beans:
- Buy whole bean and grind fresh if you can
- If you buy pre-ground, make sure it's labelled coarse
Freshly ground coffee loses aroma fast. Whole beans keep it for weeks.
How to Make Cold Brew Coffee Concentrate at Home: Step by Step
The process is simple: combine, steep, strain. No heat, no machine, no fuss. Here's the full method.
Step 1: Combine Coffee and Water
Add your coarse grounds to a large jar or bowl. Pour cold filtered water over them. Use the 1:4 ratio.
Stir gently with a wooden spoon until every ground is wet. Dry pockets at the bottom won't brew. Skip the vigorous whisking, since it just pushes fines into the water.
What you'll need:
- Large jar or bowl
- Coarse coffee grounds
- Cold filtered water
- Wooden spoon
- Kitchen scale (optional but helpful)
Step 2: Cover and Steep
Cover the jar with a lid, plate or cling film. Leave it on the counter at room temperature for 12 to 18 hours, or move it to the fridge for 18 to 24 hours.
Room temperature brews faster and extracts more. The fridge is slower and gentler, giving a cleaner cup. Try both and see which you prefer.
Step 3: Strain the Concentrate
Set a fine-mesh strainer over a bowl and line it with cheesecloth or a paper filter. Pour the mixture through slowly. Don't press the grounds down, since that forces sediment through.
For a clearer concentrate, strain twice. The second pass catches the fine particles that cloud your drink. Expect a little sediment no matter what, even with a good filter.
How Long to Steep Cold Brew Concentrate (Room Temp vs Fridge)
Steeping time is the biggest lever you control, and it changes everything about the final cup.
| Method | Steeping Time | Result |
|---|---|---|
| Room temperature | 12-18 hours | Faster, bolder, slightly more acidity |
| Refrigerator | 18-24 hours | Slower, smoother, cleaner finish |
| Too short (under 8 hours) | - | Weak, watery, flat |
| Too long (over 24 hours) | - | Bitter, harsh, muddy |
Set a timer. Overnight works well if you start at 8 pm and strain the next afternoon. A 24-hour steep is the outer limit before bitterness creeps in.
Room temperature steeping is fine for most home kitchens. Just keep the jar covered and out of direct sun.
How to Dilute Cold Brew Concentrate for Iced Coffee
Dilution is where most people guess, and guessing is why their cold brew tastes off. The right concentrate-to-water ratio depends on how strong you made it, and on how you plan to drink it.
For a 1:4 concentrate, dilute 1:1. One part concentrate, one part cold water or milk. That gives you a balanced, full-strength iced coffee.
Want it stronger? Use 2 parts concentrate to 1 part water. Want it lighter? Go 1:2.
Try these serving ideas:
- Classic iced coffee: 1:1 with cold filtered water, poured over ice
- Creamy version: 1:1 with milk of choice
- Nitro-style: 2:1 with cold water, shaken hard for foam
- Sweet treat: 1:1 with milk and a spoon of syrup
Serve over plenty of ice. Ice melts and dilutes as you drink, so start slightly stronger than you think you need.
Serving Sizes and Caffeine Expectations
A common mistake is assuming every jar of concentrate delivers the same caffeine. It doesn't. Caffeine varies with the bean, the roast, the ratio, and how long you steeped. Two batches made with the same recipe can differ noticeably if you switch beans.
A practical way to think about it: a typical 1:1 diluted serving of cold brew concentrate lands in the same general range as a standard cup of drip coffee, but treat that as a rough guide, not a guarantee. If you are sensitive to caffeine, start with a smaller serving and see how you feel.
For everyday drinking, most people find a 240 ml (8 oz) diluted serving is a comfortable single portion. If you want a bigger glass, dilute a little more rather than pouring extra concentrate, since the caffeine adds up faster than the flavour does.
Storing Cold Brew Concentrate: Shelf Life and Food Safety
Concentrate keeps well, but only if you store it right. Keep it in a sealed jar or bottle in the refrigerator. Glass is better than plastic because it doesn't hold onto flavours and is easier to clean thoroughly between batches.
Container Choice
- Glass jar with a tight lid: best for flavour and easy to see sediment
- Bottle with a screw cap: good for pouring, but check the seal
- Plastic: workable short term, but it can pick up and pass on odours
Whatever you use, wash it with hot soapy water and let it dry fully before filling. A damp container invites spoilage faster.
Refrigeration and Time Limits
- Keep it cold. Leave concentrate out at room temperature for no more than two hours.
- Seal it tight. Oxygen dulls the flavour within a day or two.
- Label the date. You'll forget when you made it.
- Check before drinking. If it smells sour, looks fizzy, or has a film on top, pour it out.
As a working guide, most home batches stay at their best for about one week in the fridge. Some people stretch it to two weeks, but flavour fades and the risk of spoilage rises. If in doubt, throw it out.
For food safety guidance on storing brewed coffee and other prepared drinks, the USDA FoodSafety.gov storage charts are a solid reference for home kitchens.
Make-Ahead Planning
Brew a large batch on Sunday, strain it, and you've got cold brew for the week. Just shake the jar before pouring, since natural separation happens. If you won't finish a batch within a week, freeze portions in ice-cube trays and thaw what you need.
Troubleshooting Weak, Bitter, or Cloudy Cold Brew Concentrate
Most cold brew problems come down to three things: grind, time and filtration. Here's how to fix each one.
Weak concentrate
- Grind too coarse, or steep time too short
- Fix: add an hour or two to the steep, or use a slightly finer coarse grind
- Check your ratio, since too much water dilutes everything
Bitter concentrate
- Steeped too long, or water too warm
- Fix: cut the steep time and move the jar to the fridge
- Avoid dark, very fine grounds, which turn bitter fast
Cloudy concentrate
- Fine particles slipping through the filter
- Fix: strain a second time through a paper filter or cheesecloth
- Let the concentrate settle in the fridge, then pour off the clear liquid on top
Sour or flat concentrate
- Stale beans, or the brew sat too long after straining
- Fix: use freshly roasted beans and drink within a week
A common mistake is blaming the beans when the real issue is grind size. Fix the grind first, then adjust time.
Making cold brew at home is easy once you've got the ratio, the grind and the steep time locked in. The hard part is finding beans worth brewing, and that's where CuppaCrave comes in. Our beans are roasted to order for maximum flavour and freshness, delivered straight to your door, with easy automated fulfilment you can pause whenever you like. Start with our Cold Brew Coffee blend and taste the difference fresh roasting makes. Get started with CuppaCrave and brew a better jar this week.
Frequently Asked Questions
What is the best coffee-to-water ratio for cold brew concentrate?
A 1:4 ratio by weight works best for a true concentrate: 100 grams of coarsely ground coffee to 400 grams of filtered water. By volume, that is roughly 1 cup of grounds to 2 cups of water, though weight is more consistent. This ratio produces a strong concentrate you dilute before drinking. If you prefer a milder concentrate, move toward 1:5; for a bolder one, try 1:3.
How long should cold brew concentrate steep?
Steep at room temperature for 12 to 18 hours, or in the refrigerator for 18 to 24 hours. Room-temperature steeping extracts faster and can turn bitter past 18 hours, while refrigerated steeping is slower and more forgiving. Taste at the 12-hour mark and decide whether you want more depth. Strain as soon as the flavor suits you.
How long does homemade cold brew concentrate last in the refrigerator?
Stored in a sealed jar or bottle in the refrigerator, cold brew concentrate keeps about 1 to 2 weeks. Keep it cold the whole time, since leaving it at room temperature lets flavor fade and creates a food-safety risk. If you notice an off smell, visible mold, or a fizzy texture, discard the batch rather than trying to salvage it.
How do you dilute cold brew concentrate for iced coffee?
Start with a 1:1 ratio of concentrate to water or milk, then adjust to taste. For a lighter drink, use 1 part concentrate to 2 parts water or milk. Pour over ice and stir. If you want to keep the drink strong as the ice melts, freeze some concentrate in an ice cube tray and use those cubes instead of plain ice.