Guide · Grinders
Grind size for cold brew: why coarse is the usual choice, and when to go finer
Most cold brew makers want coarse or extra-coarse coffee, but Hario's mesh jug asks for medium-fine. Here's why, how grind affects steep time and filtering, and what to do with pre-ground.
The usual grind size for cold brew is coarse, and Toddy goes as far as recommending the coarsest setting on your grinder. Because the coffee sits in water for 8 to 24 hours rather than 4 minutes, a coarse grind stops it turning muddy and makes it easier to filter. There’s one notable exception: Hario tells you to use a medium-fine grind in its Mizudashi jug. So the honest answer is to start with your maker’s instructions. We haven’t tested this in person. This guide is based on instructions from Toddy, Hario and Starbucks at Home, plus UK supermarket listings checked on 3 Oct 2026. Read how we compare.
Grind size for cold brew: what the makers say
| Maker or method | Grind | Steep |
|---|---|---|
| Toddy Cold Brew System | Coarse, ideally the coarsest setting | 8 to 24 hours at room temperature |
| Starbucks at Home cafetière cold brew | Coarse | 12 hours |
| Hario Mizudashi mesh jug | Medium-fine | About 8 hours in the fridge |
Hario takes the opposite view for its jug. Its manual says coarse grounds extract less efficiently and make a weak brew, while very fine coffee gets through the mesh and makes the drink grainy. That’s why it settles on medium-fine.
Who it isn’t for: anyone hoping for one setting that suits every maker. The filter you use matters as much as the grind.
Extra coarse: what it looks like, and how it differs from cafetière
A cafetière grind is already coarse: separate, gritty pieces about the size of coarse sea salt. For a Toddy-style concentrate, you go a step further, to the coarsest setting your grinder has.
Toddy’s FAQ gives two practical tips:
- Buying from a coffee shop? Ask for a French press (cafetière) grind.
- Blade grinder with no settings? Grind for about 75% of the time you’d use for hot coffee.
Cold brew can go coarser than cafetière because time does the work that heat does. Our guide to grind size for a cafetière shows what coarse looks like.
How grind affects steep time and filtering
Steep time
Finer coffee gives up its flavour faster, and coarser coffee more slowly. Toddy says 8 to 24 hours and Starbucks says 12, while Hario’s finer medium-fine grind is ready in about 8.
If your cold brew is weak, Hario’s manual suggests the grind may be too coarse for its jug. If it’s harsh or muddy, the grind may be too fine for your filter. Change one thing at a time.
Filtering
This is where grind matters most:
- Felt or paper filters (Toddy): too fine and they clog. Toddy’s FAQ says a coarse grind lets water reach all the coffee without blocking the filter.
- Mesh baskets (Hario): very fine particles pass straight through and end up in your glass.
- Cafetière plungers: a fine grind makes the plunger hard to push and leaves sludge. Starbucks suggests pressing slowly, and pouring through a paper filter as well if you want a cleaner drink.
Who it isn’t for: anyone short on time. All of these methods need hours. If you want a cold coffee today, our iced coffee at home guide covers quicker ways.
Ratios that go with the grind
The makers’ starting recipes:
- Toddy: 340g of coarse coffee with 1.9 litres of water. Dilute the concentrate 1 part to 2 parts water or milk, and it keeps for up to 2 weeks in the fridge.
- Starbucks at Home cafetière: 22g of coarse coffee per 180ml of water, steeped 12 hours, then served 1 part to 1 part water over ice.
- Hario Mizudashi 1,000ml: 80g of medium-fine, dark-roasted coffee with about 1,150ml of water. Hario says to remove the strainer once it’s brewed, or the coffee turns bitter, and to drink it within 2 to 3 days.
Pre-ground coffee for cold brew
If you don’t have a grinder, look for packs labelled for cafetières. AeroPress notes that most shop-bought ground coffee is a medium grind made for filter machines, which is finer than ideal for a Toddy. In a cafetière or jug it works, with more sediment.
From Morrisons’ cafetière coffee search, checked 3 Oct 2026:
- Costa Dark Amazonian Blend Ground for Cafetière & Filter, 200g: £3.50 at Morrisons (checked 3 Oct 2026).
- Morrisons French Style Ground Coffee, 227g: £3.60 at Morrisons (checked 3 Oct 2026).
Check price at Morrisons. Our guide to the best coffee for cold brew covers beans in more detail.
Who it isn’t for: anyone who wants the cleanest cold brew. Grinding coarse at home gives you more control.
Where to go next
Choosing a maker? See the best cold brew coffee makers. For grinders that do coarse well, see the best coffee grinder for a French press or browse our coffee grinders. Brewing hot as well? See grind size for an AeroPress.
FAQ
Is cold brew grind the same as French press? Very close. Both are coarse. Toddy even suggests asking a coffee shop for a French press grind.
Can you use fine coffee for cold brew? It tends to clog filters and leave sediment. Hario’s jug is the exception, and it asks for medium-fine, not fine.
Why is my cold brew weak? The grind may be too coarse for your maker, the steep too short, or the ratio too low. Change one thing at a time.