To make cold brew concentrate, steep coarsely ground coffee in cold water at a strong ratio -- roughly 1 part coffee to 4 or 5 parts water -- for 12 to 24 hours in the fridge or on the counter, then filter out the grounds. That is the short version of how to make cold brew concentrate: a dense, smooth coffee base you dilute to taste with water or milk. The strong ratio is the whole trick, and it is what separates a concentrate from a ready-to-drink batch.
Below is a full cold brew concentrate recipe -- the grind, the ratio, the steep, the filter, and how to cut it down to a finished glass -- plus a quick reference table you can keep on the fridge. If you want the drink defined first, our explainer on what cold brew concentrate is covers the what and why; this guide is about the how.
What cold brew concentrate is, in brief
Cold brew concentrate is not a different drink or a different method from ordinary cold brew. It is the same slow, heat-free steep, simply brewed much stronger. All cold brew works by soaking coarse grounds in cool water for many hours, which pulls out a rounder, sweeter, lower-acid flavor than hot brewing. Concentrate just uses far more coffee per unit of water, so the finished liquid is intense and meant to be diluted before it reaches your glass.
If you make cold brew the standard way and often find it either watery or too strong, brewing a concentrate is the fix: you steep deliberately strong, then dilute on demand. That single choice saves fridge space, keeps the coffee fresh longer, and lets you build a different drink each time from one jar. For the plain ready-to-drink version and the two main brewing setups, see our companion guide on how to make cold brew coffee -- the process here is identical, only the ratio changes.
The cold brew concentrate ratio
The number that matters most is the cold brew concentrate ratio: how much coffee you use per unit of water, measured by weight. A good starting point for concentrate is around 1:4 to 1:5 coffee to water -- for example, 100 g of coffee to 400 or 500 ml of water. That is noticeably stronger than a ready-to-drink cold brew, which usually lands around 1:8 or weaker.
Treat those figures as a hedge, not a law. Your beans, grind size, steep time, and how hard you like to dilute all move the sweet spot, so brew one batch, taste it diluted, and adjust the next. A stronger concentrate is the more flexible choice because you can always add more water; a weaker one is harder to rescue if it comes out thin. For the wider logic of coffee strength and how ratios translate across brew methods, our guide to coffee brewing ratios breaks the math down.
Grind and steep time
Two variables besides the ratio shape the result: the grind and the steep.
Grind coarse. Aim for a coarse texture, like raw sugar or coarse breadcrumbs -- the same setting you would use for a French press. Fine grounds over-extract badly over such a long steep, turning the concentrate muddy and bitter, and they are almost impossible to filter out cleanly. Grinding just before you brew gives the freshest, sweetest cup.
Steep 12 to 24 hours. Longer means stronger, up to a point, and also more bitter. Around 16 to 18 hours suits most palates for a concentrate. Steeping in the fridge is a touch slower and cleaner-tasting; leaving the jar on the counter is slightly faster and bolder. Past roughly 24 hours you start trading sweetness for flat, woody notes, so set a timer rather than forgetting it overnight into a second day.
How to make cold brew concentrate step by step
Here is the full method for concentrated cold brew. You need coarse coffee, cold water, a jar or pitcher, and something to strain with -- a fine mesh sieve plus a paper filter or a clean cloth.
- Weigh the coffee. Measure your coarse grounds on a kitchen scale. A scale is far more reliable than scooping, because grind and bean density throw off volume measures.
- Combine with cold water. Add the grounds to the jar and pour cold or room-temperature water over them at your chosen ratio, starting near 1:5 if you are unsure. Filtered water gives the cleanest taste.
- Stir once. Give it a gentle stir so every ground is wet, with no dry clumps floating on top. Even wetting means even extraction.
- Cover and steep. Seal the jar and leave it 12 to 24 hours, in the fridge for a cleaner result or on the counter for a bolder one.
- Filter out the grounds. Pour the brew through a fine mesh sieve to catch the bulk of the grounds, then through a paper filter or cloth to polish out the fines. Do not press or wring the grounds hard, which squeezes out bitterness.
- Bottle and label. Pour the strained concentrate into a clean, sealable bottle and note the date so you know how fresh it is.
The table below is the whole recipe at a glance -- each stage, its ratio or time, and the thing to remember.
| Stage | Ratio / time | Note |
|---|---|---|
| Grind | Coarse, like French press | Too fine turns the batch muddy and bitter and clogs the filter |
| Ratio | ~1:4 to 1:5 coffee to water, by weight | Stronger than ready-to-drink; adjust to taste |
| Steep | 12 to 24 hours | Longer is stronger and more bitter; fridge is cleaner, counter is bolder |
| Filter | Mesh, then paper or cloth | A second pass gives a clearer, silt-free base |
| Dilute | ~1:1 with water or milk, over ice | Go a touch stronger since melting ice waters it down |
| Store | Sealed in the fridge, best within 1 to 2 weeks | When in doubt, throw it out |
How to dilute cold brew concentrate
The concentrate is a base, not a finished drink, so the last step happens in the glass. A common starting point is roughly 1:1 -- one part concentrate to one part water, milk, or a milk alternative, poured over plenty of ice. From there, adjust: add more water if it drinks too strong or bitter, less if it tastes thin and washed out. Because ice melts as you sip and dilutes further, many people mix a touch stronger than 1:1 so the last mouthfuls do not go watery.
Stir or shake after diluting, since concentrate is dense and can settle. Remember that a strong ratio concentrates the caffeine too, so a small undiluted pour packs a punch -- start with more dilution than you think you need and taste as you go. If you want to fine-tune strength like a barista, the same ratio thinking that guides the brew applies to the dilution just as much.
Iced and hot uses
Iced is the natural home for concentrate. Cut it with cold water for a black iced coffee, or with milk or oat milk for a smooth iced latte, and top it with foam for a cafe-style finish. For the full iced routine -- glass, ice, order of pouring -- see our guide on how to make iced coffee. Concentrate also slips neatly into blended drinks, and a small undiluted pour adds a coffee kick to a milkshake or a smoothie without watering it down.
It works hot, too. Dilute concentrate with hot water instead of cold for a fast, low-acid hot cup -- handy when you do not want to brew from scratch. It will taste smoother and less bright than freshly brewed hot coffee, which some people prefer and others miss, so treat it as its own thing rather than a like-for-like swap.
Storage and shelf life
Kept sealed in the fridge, cold brew concentrate usually stays at its best for about one to two weeks -- noticeably longer than diluted cold brew, which is best within a few days. The higher strength and lower water content are part of why it holds up: with less water in contact with the coffee, it is slower to taste flat and stale. Store it away from strong-smelling foods so it does not pick up odors, and keep the lid tight.
Flavor fades over time even while the coffee is perfectly fine to drink, so the brightest, most balanced days are the first several. A good habit is to dilute only what you plan to drink and keep the rest as concentrate, which stretches its useful life. Give an older batch a sniff and a small taste before you commit to it, and when in doubt, throw it out.
The takeaway
Making cold brew concentrate is the same patient steep as any cold brew, just brewed strong: coarse grind, a 1:4 to 1:5 ratio, 12 to 24 hours, a careful filter, then dilute to taste. Nail those and you have a versatile base in the fridge that becomes iced coffee, an iced latte, a quick hot cup, or a splash in a dessert, each one dialed to exactly the strength you want. Brew a batch or two, tune the ratio and steep to your own palate, and it quickly turns into a no-effort habit.