- What you need
- The ratio: how much coffee to water
- How to make cold brew coffee, step by step
- How to store and dilute cold brew
- What to fix when cold brew tastes wrong
- Frequently asked questions
Cold brew is coffee brewed with time instead of heat. For what it is, why it tastes so smooth and which beans suit it, see our cold brew guide. This post is the method, from equipment to what to fix when a batch tastes wrong.
Key takeaways
- Grind medium-coarse, about the texture of sea salt, and grind just before you brew.
- Weigh the coffee and the water. A 1:6 ratio makes a strong concentrate to dilute, and 1:15 makes a lighter brew.
- Steep for 12 to 18 hours, in the fridge or at room temperature, then filter and refrigerate.
- Sour means under-extracted and bitter means over-extracted. Change one thing at a time.
- For a cleaner cup, filter a second time through paper, and rinse paper filters first.
What you need
- Coffee. Freshly roasted beans. For black cold brew, a light or filter roast works best.
- A grinder. Ground coffee oxidises and loses aroma, so grind just before you brew. No grinder? Our cold brew range comes in a coarse cold brew grind as well as whole beans.
- Scales, to keep the ratio accurate.
- Filtered water, for clean, consistent flavour. Cold is best, but cool or room-temperature water works.
- A jar, jug or brewer to steep in, and a container for the fridge.
- A spoon or paddle to stir with.
- A filter: a fine mesh sieve, cloth, paper or a reusable nylon filter.
Hario or Toddy?
A dedicated brewer builds the filter in. The Hario and the Toddy are both made for cold brew, and they suit different batch sizes.
| Hario Cold Brew Pot | Toddy cold brew system | |
|---|---|---|
| Size | One-litre glass pot | Made for larger batches |
| Filter | Permanent filter inside the pot | Two reusable filters, replaced after 10 to 12 uses or three months |
| Where it steeps | In the fridge | In the fridge or at room temperature |
| Steep time | 12 to 18 hours | 12 to 18 hours |
| What you get | A clean, smooth cup | A large batch that keeps in the fridge for up to seven days |
Shop the Hario Cold Brew Pot, the Toddy cold brew system and replacement Toddy filters.
The ratio: how much coffee to water
The ratio is the weight of coffee to the weight of water, so 1:10 means one gram of coffee for every 10 grams of water. Weigh both. A litre of water weighs 1,000g.
We brew cold brew between 1:5 and 1:15, depending on the system. Our starting recipe for a concentrate is 1:6, which is strong, so you dilute it before drinking. Go wider, towards 1:15, for a lighter brew.
| Water | Coffee at 1:6 (concentrate) | Coffee at 1:10 | Coffee at 1:15 (lighter) |
|---|---|---|---|
| 500g | 83g | 50g | 33g |
| 750g | 125g | 75g | 50g |
| 1,000g | 167g | 100g | 67g |
| 1,500g | 250g | 150g | 100g |
Some coffees have their own recipe. Our Strawberry Scoop is brewed at 1:18 for 11 hours in the fridge, and every cold brew release we make comes with a brew card giving its grind, ratio and steep time. If your bag has one, follow it.
How to make cold brew coffee, step by step
- Grind. Grind medium-coarse, about the texture of sea salt, just before you brew. A coarser grind releases flavour slowly, which suits a long steep.
- Combine. Put the coffee in your jar or brewer and pour in cold filtered water.
- Stir. Stir gently at the start until every ground is wet, so the coffee extracts evenly.
- Steep. Cover and leave it for 12 to 18 hours, in the fridge or at room temperature. Twelve hours is a good first test. After that, adjust the time to make the coffee stronger or lighter.
- Filter. Pour it through a fine mesh sieve or a cold brew filter. For a cleaner cup, filter it again through paper, which catches the fine particles a metal filter lets through.
- Chill. Move the coffee to a container and put it in the fridge.
In a Hario Cold Brew Pot
Add coarsely ground coffee to the Hario's filter. Fill the filter with cold filtered water and stir gently until all the grounds are wet. Cover and steep in the fridge for 12 to 18 hours, then remove the filter and serve over ice or with milk.
In a Toddy
Add coarsely ground coffee to the brewing chamber, pour in filtered water and stir gently until the grounds are evenly wet. Steep at room temperature or in the fridge for 12 to 18 hours. Carefully remove the coffee bed and filter, then transfer the coffee to a storage container.
How to store and dilute cold brew
Store it in the fridge. Cold brew does not need the fridge while it steeps, but it goes in once it is brewed. It keeps there for several days, and we give a Toddy batch up to seven. Filter it before you store it: coffee left sitting on the grounds keeps extracting and turns bitter.
Dilute to taste. If you brewed a concentrate, add water or milk a little at a time and taste as you go until it is balanced. Ice dilutes it too as it melts, so go easy on the water if the glass is full of ice. A lighter brew near 1:15 may need nothing added, so taste it first.
What to fix when cold brew tastes wrong
Most problems come down to extraction, the process of dissolving flavour from the grounds into the water. Under-extracted coffee tastes sour and lacks sweetness, and over-extracted coffee tastes bitter. Change one thing at a time, so you know what made the difference.
| What you taste | Likely cause | What to change next batch |
|---|---|---|
| Sour, thin, not sweet | Under-extracted | Steep longer, or grind a little finer |
| Bitter, harsh or dry | Over-extracted | Steep for less time, or grind coarser |
| Weak or watery | Too little coffee for the water | Use more coffee, for example 1:10 instead of 1:15 |
| Too strong | A concentrate that still needs diluting | Add water or milk a little at a time |
| Gritty or cloudy | Fine particles getting through the filter | Filter again through paper |
| Papery | A paper filter that was not rinsed | Rinse paper filters before you use them |
| Flat, with little aroma | Coffee ground too early, or beans past their best | Grind just before brewing, using freshly roasted coffee |
| Different from last time, same recipe | Your water, or more than one change at once | Use filtered water, and change one thing at a time |
Grind and steep time work together. A finer grind extracts faster, so if you go finer, you may need a shorter steep. Our guide to coffee brewing terms explains how these variables connect.
Frequently asked questions
Do you need special equipment to make cold brew?
No. A jar or jug, a spoon and a fine mesh sieve are enough, along with a grinder and scales if you have them. A dedicated brewer makes it tidier: the Hario Cold Brew Pot has a permanent filter built in, and the Toddy comes with two reusable filters and a glass decanter with a lid.
Should cold brew steep in the fridge or at room temperature?
Either works. Cold brew does not need to steep in the fridge, so you can leave it covered at room temperature. Some brewers are set up for one or the other: our Hario guide steeps in the fridge, while the Toddy can steep on the bench or in the fridge. Whichever you choose, refrigerate the coffee once it is brewed.
Can you steep cold brew for too long?
Yes. Leave the water on the grounds too long and it pulls out the heavier, bitter compounds, which is over-extraction. Our general range is 12 to 24 hours, typically 12 to 18. If your cold brew tastes bitter, shorten the steep or grind coarser next time, changing one of those at a time.
Can you use pre-ground coffee for cold brew?
You can, but grinding fresh gives better flavour, because ground coffee oxidises and loses aroma. If you buy it ground, ask for a coarse grind. Our cold brew coffees come in a cold brew grind, ground coarse specifically for cold brew, or as whole beans if you would rather grind your own.