Percolate
How to Make Cold Brew Coffee at Home (Ratios & Tips)
Combine coarsely ground coffee and cold filtered water at a 1:5 ratio by weight, stir to saturate all grounds, cover, and steep in the refrigerator for 14-16 hours. Strain through a fine-mesh sieve or paper filter, then dilute 1:1 with water or milk before serving. No heat, no special equipment required.
Cold brew is one of the most beginner-friendly brews you can make at home, and it rewards the specialty coffee drinker who already cares about freshness, bean quality, and dialing in variables. The catch is that most guides bury the two numbers that actually matter — your brew ratio and your steep time — under marketing copy. This article cuts straight to both.
What is cold brew, and how is it different from iced coffee?
Cold brew is not iced coffee. Iced coffee is hot-brewed and then chilled. Cold brew is never exposed to heat, and because heat is absent, many of the acidic compounds that form during conventional brewing simply never develop, giving cold brew its characteristic smooth, low-bitterness character.
Cold brew is made by steeping coarsely ground coffee in cold water for 12-16 hours, then straining. The result is a naturally sweet concentrate with roughly 65% less acidity than hot-brewed coffee.
That lower acidity matters to specialty drinkers who spend real money on single-origin bags. High-altitude African coffees, prized for their brightness in a pour-over, can be overwhelming for people with sensitive stomachs. Cold brew offers a different lens on the same beans — one that preserves sweetness while softening sharp edges.
What ratio do I actually use — and what’s the difference between concentrate and ready-to-drink?
A question we hear often: people assume there’s one “cold brew ratio” and are confused when their batch tastes completely different from a cafe bottle.
There are actually two separate ratios in cold brew, and mixing them up is the single most common reason home batches taste either weak or overwhelmingly strong. The first is the brew ratio — coffee to water in your jar. For concentrate, use 1:5 by weight (200 g coffee to 1,000 g water). For a gentler concentrate, go 1:6. The second is the dilution ratio — concentrate to water or milk in the glass. Start at 1:2 (one part concentrate, two parts liquid) and adjust from there.
If you want a ready-to-drink batch you can pour straight from the jar, use a 1:8 ratio and skip the dilution entirely.
Volume measurements for coffee can vary by up to 20% depending on grind coarseness and how the grounds settle. At a 1:5 ratio, that error is the difference between a syrupy concentrate and a thin, disappointing one. Use a kitchen scale, not tablespoons.
| Style | Brew Ratio (coffee:water) | Dilution Before Serving | Typical Use |
|---|---|---|---|
| Strong concentrate | 1:4 | 1:1 with water or milk | Small batches, quick cups |
| Standard concentrate | 1:5 | 1:1 to 1:2 with water or milk | Most home brewers |
| Gentle concentrate | 1:6 | 1:1 with water or milk | Sensitive palates, lighter beans |
| Ready-to-drink | 1:8 | None needed | Larger batches, grab-and-go |
What grind size should I use for cold brew?
This one comes up a lot: people reach for their everyday drip setting and end up with a sludgy, bitter mess that won’t filter.
Aim for a grind slightly coarser than French press — chunky, like raw sugar. Too fine and the long steep pulls bitter, dusty flavors plus a sludge you’ll never fully filter. Too coarse and 16 hours won’t extract any sweetness worth mentioning.
Fine grind in cold brew produces bitter, over-extracted results and is nearly impossible to filter cleanly. If you’re grinding at home, set your burr grinder two or three clicks coarser than your French press setting and you’ll land in the right zone.
How long should I steep cold brew — and does the fridge vs. room temperature matter?
The sweet spot for most people is 14-16 hours, which produces a smooth, full-bodied concentrate with balanced sweetness. You can push to 20 hours if you want it extra strong. Under 12 hours and it’ll taste weak and underdeveloped.
On the fridge-versus-counter debate: room temperature is faster (10-12 hours gets you there) but the slightly warmer extraction can produce a harsher, more volatile result. Fridge steeping is slower, but the controlled cold temperature generally delivers a cleaner, sweeter cup. For specialty beans where you’re paying for nuance, use the fridge.
One thing that surprises many home brewers: a longer steep time doesn’t mean more caffeine. Most caffeine is extracted in the first few hours, so extending the steep simply intensifies flavor — and if it goes too long, that means over-extracted bitterness rather than more kick.
Which beans work best for cold brew?
Readers frequently ask: “Do I need a special cold brew bean, or can I use whatever’s on my shelf?”
Because cold water extracts differently than hot water, the bean’s natural flavor characteristics come through clearly. Different single-origin coffees produce dramatically different cold brews — chocolatey Brazils, fruity Ethiopians, caramelly Colombians.
Medium to medium-dark roasts with chocolate or caramel notes are the easiest starting point for beginners, but that’s a preference baseline, not a rule. Light roasts from high-altitude origins like Ethiopia or Kenya can produce stunning cold brews — intensely fruity and naturally sweet — once you’ve got your ratio and steep time dialed. The variable that matters most isn’t roast level, it’s freshness. Use coffee roasted in the last four weeks. Cold brew is forgiving, but it can’t rescue stale beans — it just makes their cardboard notes cold.
If you’re using the Percolate app to track your coffee shelf, the roast date field makes this easy — sort by date roasted and reach for whatever was roasted most recently when you’re planning a cold brew batch.
Step-by-step: how do I actually make a batch at home?
No special equipment required — a large mason jar or pitcher works perfectly.
- Weigh your coffee and water. For a 1-liter batch of concentrate, use 200 g of coarsely ground coffee and 1,000 g of cold filtered water.
- Combine and stir. Add the coffee to your jar or pitcher, pour in the water, and stir until all the grounds are wet. Cover it up.
- Steep in the fridge for 14-16 hours. Resist the urge to check it or stir it mid-steep.
- Strain. Pour through a fine-mesh strainer lined with cheesecloth into a clean jar or pitcher. A paper coffee filter works too, though it’s slower. If you brewed in a French press, simply press the plunger and pour.
- Double-strain if needed. If you see cloudiness or fine grounds in the finished concentrate, run it through a second time. Don’t squeeze or press the grounds — that forces bitter compounds into your final product.
- Dilute and serve. Start at 1:1 (concentrate to water or milk) over ice, and adjust to taste from there.
How long does homemade cold brew keep, and how should I store it?
Shelf life runs up to two weeks refrigerated, with best flavor in the first 7-10 days. Store your concentrate in a sealed glass container — a mason jar with a tight lid is ideal. Oxygen is the enemy once it’s brewed, so keep it sealed between pours.
One batch brews overnight, keeps for up to two weeks, and makes a cup in about 30 seconds. That’s a time-to-effort ratio that makes cold brew sustainable as a weekly ritual, especially during warm months. It’s also worth noting that cold brew isn’t a seasonal thing anymore — in 2026, people drink it year-round.
How do I troubleshoot cold brew that tastes off?
| Problem | Most Likely Cause | Fix |
|---|---|---|
| Weak and watery | Ratio too low, or grind too coarse | Move to 1:5 and 18 hours |
| Bitter or ashy | Grind too fine, or steeped too long | Grind coarser; cap at 16 hours |
| Sour and thin | Under-extracted | Extend steep by 3-4 hours, or grind slightly finer |
| Cloudy/silty | Grind too fine, or filter too loose | Strain twice; use a paper filter for the second pass |
| Flat and cardboard-y | Stale beans | Use coffee roasted within the last 4 weeks |
Change one variable at a time. Grind and steep time are the two highest-leverage variables in cold brew — adjusting both at once makes it impossible to know what actually moved the needle. Lock in your grind, then experiment with time. Once time is dialed, experiment with ratio.
FAQs
What ratio should I use for cold brew coffee? Use a 1:5 coffee-to-water ratio by weight for a concentrate (e.g., 200 g coffee to 1,000 g water), then dilute 1:1 with water or milk before drinking. For ready-to-drink cold brew, use 1:8 and serve straight.
How long should I steep cold brew coffee? The sweet spot is 14-16 hours refrigerated. Under 12 hours tastes weak and underdeveloped. Over 20 hours risks over-extraction and bitterness. Start at 15 hours and adjust from there.
Can I steep cold brew at room temperature instead of in the fridge? Yes. Room-temperature steeping works in about 10-12 hours and produces a slightly different, sometimes harsher, flavor profile. Refrigerator steeping is slower but generally produces a cleaner, sweeter result.
What grind size is best for cold brew? Use an extra-coarse grind, similar to raw sugar or crushed sea salt. Fine or medium grinds over-extract during the long steep and make the cold brew bitter and nearly impossible to filter cleanly.
How long does homemade cold brew keep in the fridge? A sealed concentrate will stay fresh for up to two weeks refrigerated, though flavor is best in the first 7-10 days. Always use fresh-roasted beans — cold brew amplifies stale notes rather than hiding them.
What’s the difference between cold brew and iced coffee? Iced coffee is hot-brewed and then chilled. Cold brew is never exposed to heat — it steeps entirely in cold water. The absence of heat means fewer acidic compounds form, producing a naturally smoother, lower-acidity cup.
Related
Frequently Asked Questions
What ratio should I use for cold brew coffee?
Use a 1:5 coffee-to-water ratio by weight for a concentrate (e.g., 200 g coffee to 1,000 g water), then dilute 1:1 with water or milk before drinking. For ready-to-drink cold brew, use 1:8 and serve straight.
How long should I steep cold brew coffee?
The sweet spot is 14-16 hours refrigerated. Under 12 hours tastes weak and underdeveloped. Over 20 hours risks over-extraction and bitterness. Start at 15 hours and adjust from there.
Can I steep cold brew at room temperature instead of in the fridge?
Yes. Room-temperature steeping works in about 10-12 hours and produces a slightly different, sometimes harsher, flavor profile. Refrigerator steeping is slower but generally produces a cleaner, sweeter result.
What grind size is best for cold brew?
Use an extra-coarse grind, similar to raw sugar or crushed sea salt. Fine or medium grinds over-extract during the long steep and make the cold brew bitter and nearly impossible to filter cleanly.
How long does homemade cold brew keep in the fridge?
A sealed concentrate will stay fresh for up to two weeks refrigerated, though flavor is best in the first 7-10 days. Always use fresh-roasted beans -- cold brew amplifies stale notes rather than hiding them.
What's the difference between cold brew and iced coffee?
Iced coffee is hot-brewed and then chilled. Cold brew is never exposed to heat -- it steeps entirely in cold water. The absence of heat means fewer acidic compounds form, producing a naturally smoother, lower-acidity cup.
