Cold Brew Coffee Recipe: Perfect Ratio, Time & Method

Last updated: April 17, 2026

Cold brew coffee is smoother, less acidic, and naturally sweeter than regular brewed coffee. The secret is time, not heat. You steep coarse coffee grounds in cold water for 12-24 hours and let the slow extraction do the work.

But the ratio matters more than anything else. Get it wrong and you get either bitter sludge or weak brown water. This guide gives you the exact ratio, steep time, and method for perfect cold brew every single time.

What Is the Best Coffee-to-Water Ratio for Cold Brew?

Answer: Use a 1:8 ratio (100g coffee to 800ml water) for concentrate that you dilute before drinking. Use 1:15 (100g coffee to 1.5L water) for ready-to-drink cold brew that needs no dilution. The 1:8 concentrate is more flexible and lasts longer in the fridge.
Ratio Coffee Water Result Best For
1:5 100g 500ml Very strong concentrate Espresso-style drinks, cocktails
1:8 100g 800ml Standard concentrate Dilute 1:1 with water or milk. Most popular ratio.
1:12 100g 1.2L Medium strength, ready to drink Black cold brew, light coffee drinkers
1:15 100g 1.5L Light, ready to drink Daily drinking, no dilution needed

The 1:8 ratio is the best starting point. It makes a concentrate that you can dilute to any strength. Mix 1 part concentrate with 1 part water for regular strength. Mix 1 part concentrate with 2 parts milk for a creamy cold coffee. You get full control over your final cup.

How Do You Make Cold Brew Coffee Step by Step?

Answer: Grind 100g of coffee beans to coarse size (like raw sugar). Add to a jar with 800ml of cold filtered water. Stir once. Cover and steep in the fridge for 12-18 hours. Strain through a fine mesh or coffee filter. Store the concentrate in the fridge for up to 2 weeks.
  1. Grind your coffee coarse. The grounds should look like raw sugar or coarse sand. If you do not have a grinder, ask your local coffee shop to grind it for cold brew. Do not use fine espresso grind — it will over-extract and taste bitter.
  2. Measure your ratio. For a standard batch: 100g coarse coffee + 800ml cold filtered water.
  3. Combine in a jar. Add the coffee to a large glass jar, pitcher, or a cold brew coffee maker. Pour the cold water over the grounds.
  4. Stir once. Give it one good stir to make sure all the grounds are wet. Do not stir again after this.
  5. Cover and steep. Put a lid on the jar and place it in the fridge. Let it steep for 12-18 hours. 16 hours is the sweet spot for most people.
  6. Strain. Pour the cold brew through a fine mesh strainer lined with a paper coffee filter or muslin cloth. This removes all the grounds and sediment.
  7. Store. Transfer the strained concentrate to a clean bottle or jar. Keep it in the fridge. It stays fresh for up to 2 weeks.

How Long Should You Steep Cold Brew Coffee?

Answer: 12 hours gives a light, mild brew. 16 hours is the sweet spot for balanced flavour. 18-24 hours gives a strong, bold concentrate. Beyond 24 hours risks bitterness. The right time depends on how strong you like your coffee and your ratio.
Steep Time Flavour Profile Best Ratio Notes
8-10 hours Weak, under-extracted Not recommended Coffee has not fully extracted. Tastes thin.
12 hours Light, smooth, mild 1:12 to 1:15 Good for ready-to-drink at lighter ratios.
16 hours Balanced, rich, sweet 1:8 to 1:12 Best starting point for most people.
18-24 hours Bold, intense, full body 1:5 to 1:8 Best for concentrates. Watch for bitterness beyond 24hr.
24+ hours Bitter, harsh, over-extracted Any Not recommended. Strain before 24 hours.

Why Does Grind Size Matter So Much for Cold Brew?

Answer: Cold brew uses long steep times (12-24 hours). Fine grinds over-extract in that time and make the coffee bitter and cloudy. Coarse grinds extract slowly and evenly, giving you a smooth, clean flavour. Using the wrong grind is the number one mistake beginners make.

Think of it like tea. If you steep a tea bag for 2 minutes, it is perfect. If you steep it for 30 minutes, it is bitter and dark. The same thing happens with coffee — fine grinds in cold water for 16 hours over-extract like crazy.

Coarse grind (like raw sugar crystals) has less surface area touching the water. This means slower, more controlled extraction. The result is smooth, sweet, and low-acid cold brew. Use your cold brew as a base for our cafe-style cold coffee recipes — the flavour is next level. Prefer hot, strong coffee? Our moka pot coffee recipe delivers bold South Indian filter-style flavour.

If you do not have a grinder: Buy whole beans and ask your local coffee shop to grind them "coarse for cold brew." Most shops will do this for free. Or use a simple hand grinder — set it to the coarsest setting.

What Is the Difference Between Cold Brew and Iced Coffee?

Answer: Cold brew is brewed cold over 12-24 hours. Iced coffee is brewed hot and poured over ice. Cold brew is smoother, less acidic, and naturally sweeter. Iced coffee is quicker to make but more bitter and acidic. They are two different drinks.
Feature Cold Brew Iced Coffee
Brew method Cold water, 12-24 hours Hot water, 3-5 minutes, then iced
Taste Smooth, sweet, chocolatey Bright, slightly bitter, acidic
Acidity 60-70% less acid than hot brew Same as hot coffee
Caffeine Higher per serving (if concentrate) Standard
Time to make 12-24 hours 5 minutes
Shelf life Up to 2 weeks (concentrate) Drink right away
Best for Batch prep, meal prep, creamy drinks Quick fix, when you need coffee now

For an easy iced coffee method using a moka pot, read our iced latte recipe. For a full look at cold brew makers, see our cold brew coffee maker guide.

Which Coffee Beans Work Best for Cold Brew in India?

Answer: Medium to dark roast Arabica beans with chocolate, nut, or caramel notes work best. Light roast gives a brighter, fruitier cold brew. Popular Indian brands: Blue Tokai (Attikan Estate), Sleepy Owl (Original), Country Bean, and Devans South Indian.
  • Blue Tokai Attikan Estate (Medium-Dark): Chocolate and nut notes. One of the best for cold brew in India. Available online.
  • Sleepy Owl Original Blend: Made specifically for cold brew. Smooth and balanced. Comes in convenient packs.
  • Country Bean Hazelnut: Flavoured option if you like nutty cold brew without adding syrup.
  • Devans South Indian Arabica: Classic Indian coffee profile. Bold and earthy. Works great with milk-based cold brew.

Budget option: Any medium-roast whole bean coffee from your local store works fine. The key is freshness — buy beans roasted within the last 2-4 weeks. Pre-ground coffee loses flavour fast.

Brew a Full Batch in One Step

The InstaCuppa Cold Brew Coffee Maker 2.2L has a built-in mesh filter. Add coarse coffee, pour cold water, steep overnight, and pour without straining. Makes 8-10 servings per batch. No mess, no paper filters.

Frequently Asked Questions

How long does cold brew concentrate last in the fridge?

Up to 2 weeks in a sealed container. After that, the flavour starts to go stale. Once you dilute it with water or milk, drink it within 2-3 days.

Can I make cold brew with instant coffee?

No. Instant coffee is already extracted and dried. It dissolves in water instantly — there is nothing to steep. Cold brew requires whole or coarsely ground beans.

Can I steep cold brew on the counter instead of the fridge?

You can, but fridge steeping gives a smoother, less acidic result. Room temperature steeping extracts faster, so reduce the time to 8-12 hours to avoid bitterness.

Why is my cold brew bitter?

Three likely causes: grind too fine, steeped too long (over 24 hours), or coffee-to-water ratio too strong. Start with coarse grind, 1:8 ratio, and 16 hours. Adjust from there.

Is cold brew stronger than regular coffee?

Cold brew concentrate (1:8 ratio) is stronger than regular coffee. But most people dilute it 1:1, which brings the caffeine to about the same level as a regular cup. The smooth taste can trick you into thinking it is weaker, so watch your intake.

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