How to Make
Cold Brew Coffee
at Home
The smoothest, least acidic coffee you can make — and it only requires 5 minutes of actual work.
Cold brew coffee has earned its obsessive following for good reason. It’s smoother than hot coffee, less acidic, naturally sweeter, and concentrated enough to last all week in your fridge. Unlike its quick cousin the iced coffee recipe, cold brew demands patience — but rewards that patience enormously.
The science is simple: instead of using heat to extract flavour from coffee grounds, you use time. Cold water slowly draws out the sugars, oils, and caffeine while leaving behind the harsh acids and bitter compounds that heat releases. The result? A coffee that even people who hate black coffee often love.
This guide covers everything: the right grind, the perfect ratio, steep time, and how to strain and store your cold brew so every glass is perfect.
Classic Cold Brew Coffee Recipe
Smooth, low-acid concentrate — 5 minutes prep, ready overnight
🛒 Ingredients
- 100g (1 cup) coarsely ground coffee
- 800ml (3⅓ cups) cold filtered water
- Large 1-litre jar or pitcher
- Fine mesh strainer + cheesecloth or paper filter
- Ice and milk to serve (optional)
👨🍳 Instructions
- Grind coffee coarsely — like raw sugar. Fine grinds over-extract and create bitterness.
- Add ground coffee to jar. Pour cold filtered water over grounds and stir gently.
- Cover and refrigerate. Steep 12–24 hours (18–20 hours is ideal).
- Strain through cheesecloth/paper filter. Do not press grounds — patience gives clarity.
- Store concentrate in sealed jar. Dilute 1:1 with water or milk over ice to serve.
Cold Brew Ratio Guide
The ratio is the most important variable in cold brew. Here’s our breakdown for every preference:
100g coffee to 800ml water. Ready-to-drink, mild and smooth.
100g coffee to 400ml water. Concentrate — dilute before drinking.
100g coffee to 200ml water. Ultra concentrate for espresso replacement.
Steep Time: What Changes?
12 hours: Lighter body, brighter with some fruity notes still present, less caffeine. 18–20 hours: The ideal balance — smooth, naturally sweet, full-bodied, strong. This is what the major cold brew brands aim for. 24 hours: Maximum extraction, very bold, slightly more bitter than 18 hours. Good if you use a lot of milk. 36+ hours: Over-extracted. Harsh, astringent notes appear. Not recommended.
Choosing the Right Coffee for Cold Brew
Medium to dark roasts work exceptionally well — their chocolate, caramel, and nutty notes come through beautifully in cold extraction. Light roasts can work but tend to taste thin and underwhelming without the heat to unlock their brighter characteristics. Single-origin Colombian and Brazilian coffees are consistently great cold brew choices.
Equipment You Can Use
You don’t need a special cold brew maker. A mason jar and some cheesecloth is all it takes. That said, a dedicated cold brew pitcher with a built-in filter makes the process even smoother — grounds go in the filter, steep, remove, done. No straining needed.
Why Cold Brew is So Much Smoother
Hot water above 90°C rapidly extracts all compounds from coffee — the good flavour compounds but also the chlorogenic acids and quinic acids responsible for bitterness and stomach irritation. Cold water extraction is selective: it slowly draws out the aromatic compounds and natural sugars while leaving the harsher acidic compounds largely locked in the grounds.
The result is a coffee that is up to 67% less acidic than hot-brewed coffee according to food science research. For people with acid reflux, GERD, or sensitive stomachs, cold brew is often a revelation — they can enjoy strong coffee without discomfort for the first time.
Frequently Asked Questions
How long should I steep cold brew coffee?
Steep for 12–24 hours in the refrigerator. The sweet spot for most people is 18–20 hours — full-bodied, smooth, and strongly flavoured without tipping into over-extracted bitterness.
What is the best coffee-to-water ratio for cold brew?
For concentrate (recommended): 1:4 ratio — 100g coffee to 400ml water. Dilute with equal parts water or milk before serving. For ready-to-drink: 1:8 ratio.
Why is cold brew less acidic than hot coffee?
Cold water doesn’t activate the extraction of the same acidic compounds that heat does. The result is a brew that is up to 67% less acidic — noticeably smoother and gentler on the stomach.
Can I make cold brew with pre-ground coffee?
Yes, but ensure it’s a coarse grind. Pre-ground “drip” coffee is usually too fine for cold brew and will result in a muddy, bitter concentrate. Ask your coffee shop to grind it coarse for cold brew, or buy whole beans and grind yourself.
How long does cold brew keep in the fridge?
Cold brew concentrate keeps for up to 2 weeks sealed in the refrigerator. Once diluted, drink within 24–48 hours. The undiluted concentrate actually improves slightly in smoothness over the first 3–4 days as the flavours mellow and integrate.
☕ Explore More Coffee Recipes
- → All coffee recipes — the complete collection
- → Iced coffee recipe — ready in 10 minutes, no steep needed
☕ Explore More Coffee Recipes
- → All coffee recipes — the complete collection
- → Iced coffee recipe — ready in 10 minutes, no steep needed
