The Coffee LocatorFind the gear. Brew it right.

Brewing Guides

How to Make Cold Brew: Ratio & Easy Method

Ratio, steep time and fixes for cold brew at home

Quick answer

Steep 100 g coarse-ground coffee in 800 ml cold filtered water (1:8) for 18 hours in the fridge, then filter through paper or cheesecloth. Dilute the concentrate 1:1 with water or milk; it keeps 10-14 days.

What do you need?

A jar is enough; a dedicated maker mainly filters faster.

  • Coffee

    Amount / why
    100 g, coarsest grind (coarse sea salt); weigh it

  • Water

    Amount / why
    800 ml cold and filtered; hard tap water dulls flavor

  • Jar

    Amount / why
    Wide-mouth, 32 oz or larger; a French press also works

  • Filter

    Amount / why
    Fine-mesh strainer with paper filter or dampened cheesecloth

  • Grinder

    Amount / why
    A burr grinder; blades make fines that cloud the brew

Cold brew has no heat to hide defects, so use fresh, good beans.

How do you make cold brew coffee at home?

Six steps; scale linearly for bigger batches.

  1. Grind coarse. , coarser than French press.

  2. Weigh. 100 g coffee and 800 g cold water.

  3. Stir gently. For 30-45 seconds so no dry pockets remain.30-45 seconds

  4. Seal and refrigerate for 18 hours. 18 hours

  5. Filter slowly. Without stirring or pressing; allow 10-20 minutes.10-20 minutes

  6. Store in sealed glass. And label the date.

Glass jar of cold brew steeping in a refrigerator with an 18 hour note
Cold brew steeping in the fridge

How long should cold brew steep?

18 hours is the sweet spot for a coarse grind.

  • 12 hours

    Result
    Thin, closer to weak iced coffee

  • 18 hours

    Result
    Full body, natural sweetness, clean finish

  • 24 hours

    Result
    Bitter, woody edge; little extra body

  • Room temp (20-22°C)

    Result
    8-12 hours; more acidic, less clean

What is the best cold brew coffee ratio?

Concentrate is the better default.

  • Per batch

    Concentrate (1:8)
    100 g : 800 ml
    Ready-to-drink (1:15)
    100 g : 1500 ml

  • Shelf life

    Concentrate (1:8)
    10-14 days
    Ready-to-drink (1:15)
    5-7 days

  • Flexibility

    Concentrate (1:8)
    Dilute to taste or with milk
    Ready-to-drink (1:15)
    Fixed strength

Quick decision guide

  • You want one jar for iced coffee, lattes and tonic

    make 1:8 concentrate and dilute to taste.

  • You only want grab-and-go glasses

    make 1:15 and finish it within a week.

How do you serve cold brew?

Most drinks take under a minute.

  • Over ice: 2-3 oz concentrate plus 2-3 oz cold water.
  • Latte: 2 oz concentrate over ice, then 2-4 oz cold milk. See also the espresso iced latte.
  • Tonic: 2 oz concentrate topped with 4 oz tonic water.
  • Warm: 1 part concentrate to about 3 parts hot water; do not heat the concentrate directly.

Use large ice cubes, since small ice melts and dilutes fast. For how it differs from other drinks, see coffee drink differences.

Why does my cold brew taste bad?

Match the symptom to the fix for the next batch.

  • Bitter, filtering takes over an hour

    Fix
    Grind too fine; use your coarsest setting. See the grind size chart

  • Cloudy, bitter

    Fix
    Grounds were pressed; let gravity filter

  • Watery

    Fix
    Too little coffee; weigh it

  • Flat or chlorine note

    Fix
    Use filtered water

  • Off-flavors after days

    Fix
    Plastic absorbs oils; store in glass

Why does cold brew taste smoother?

Cold water extracts differently, not just more slowly.

Heat drives extraction. Hot water pulls out acids, aromatic oils and bitter compounds quickly; cold water dissolves them far more slowly, so a long cold brew steep leaves much of the sharp acidity and harshness behind. That is why cold brew tastes rounder and sweeter, and why it is lower in perceived acidity rather than truly acid-free.

Because the process is immersion with a high coffee-to-water ratio, you make a concentrate that is diluted afterwards. Contact time, grind size and ratio replace temperature as your main controls: finer grounds or a longer steep raise extraction, and over-extraction shows up as woody, papery bitterness instead of sourness.

Cold brew is not the same as iced coffee, which is hot coffee chilled, or Japanese iced coffee, which is brewed hot directly over ice.

Modern fixes and current best practice

Small changes that remove most cloudy, weak or muddy batches.

  • Weigh everything. A kitchen scale makes a ratio repeatable; scoops vary with roast and grind.
  • Grind coarse and even. A burr grinder gives fewer fines than a blade, which means less silt and bitterness. See the burr vs blade grinder comparison and the grind size chart.
  • Steep in the fridge for 12-18 hours if you want a cleaner, brighter cup; room-temperature steeps extract faster and taste heavier.
  • Filter twice. Strain through a mesh, then a paper filter, for a clearer, longer-lasting concentrate.
  • Use filtered water. Chlorine and very hard water both dull the flavour of a long steep.
  • Store sealed and cold, and finish a batch within about a week.

Immersion pitchers and cold brew towers add convenience, not better flavour; a jar and a good filter produce the same extraction when the ratio and time match.

Is a cold brew maker worth it?

Only if you brew often and want faster, cleaner filtering.

Our pick

OXO Good Grips Cold Brew Maker

$52-$62

Pick it if you brew often and want less mess: the OXO Good Grips Cold Brew Maker (32 oz) filters faster. Skip it if a jar already works for you.

Check current priceRead the review

Our pick

Takeya Tritan Cold Brew Maker

$22-$32

Pick it if you want a lower-cost pitcher: the Takeya Tritan is cheaper. Skip it if you want the cleanest filtering.

Check current priceRead the review

Affiliate links: we may earn a commission at no extra cost to you.

A KitchenAid glass carafe is another reviewed option. Check the listing for current prices.

Frequently Asked Questions

Quick answers before you buy.

Only if it is coarse.

Standard pre-ground is usually too fine, which gives bitter, cloudy cold brew that is slow to filter.

Buy whole beans and grind them coarse, or ask for a French press grind.

Cold brew concentrate is stronger per ounce, but you dilute it.

Once diluted, caffeine ends up in a similar range to regular coffee.

Strength mostly depends on your ratio and dilution.

Medium to dark roasts give the chocolatey, low-acid cup most people expect. Light roasts work but taste brighter and more tea-like.

Fresh beans matter either way. See best coffee beans for espresso for ideas.

Yes.

Dilute the concentrate with hot water for an easy, smooth hot coffee.

It tastes less acidic than regular drip, though it will not taste identical.

Steep at room temperature for about 8-12 hours, then refrigerate once filtered.

It tastes more acidic and less clean than a fridge steep, so use a shorter time.

The ratio is too thin, the steep too short, or the grind too coarse.

Try 1:8 for 18 hours, then dilute less.

See our grind size chart.

Related Guides

Keep reading: more guides on the same topic.