Best Cold Brew Ratio – Bun Brewing Basics

We all love a good cold brew – rich in flavour, strong blends, and ice cold – what’s not to love?

Most generally enjoy a cold brew from their local coffee shop. However, coffee connoisseurs (like yourself) know that with the right tools, it can be done from the comfort of your own home.

With cold brew, it is all about finding the right cold brew ratio. Finding a cold brew coffee ratio that works for a passable cup is not hard — but consistently nailing the perfect ratio is something to be mastered. 

As passionate coffee roasters ourselves, we’re here to give you the basics on how to make cold coffee brew, from the ideal ratio to use, down to the steps to take, and the equipment you can purchase to perfect your brew.

Cold Brew Equipment Needed

Before you get started, make sure you’ve got the right equipment for a cold brew. Aside from coffee beans, you’ll need: 

  • A brewing container with a lid
  • Coffee filters and filtering gear 
  • A storing container
  • Coffee grinder
  • Kitchen scale
  • Stirrer
  • Drinking cups

If you don’t have a coffee grinder, don’t worry. You can also use pre-ground coffee beans for cold brew (although, freshly ground coffee beans do make a world of difference, but no judgement).

Ideal Beans for Cold Brew

As we’ve mentioned above, you won’t be doing your cold brew any favours by using pre-ground beans. Ideally, you should grind your beans just before placing them in the brewing container so that they don’t lose their fragrance over time.

It’s essentially the same principle as brewing coffee the regular way — the fresher your grind, the stronger its taste and aroma.

Darker roasts are generally considered to be the best type of roast for a cold brew as they have the least acidity, while Colombian beans are raved over for the fruity and sweet notes they add to cold brew coffee. 

There are by no means rules, and you shouldn’t feel restricted to the kind of beans to use or how they are roasted. Feel free to experiment with lighter roasts or even Single Origin coffee beans. We say: your coffee, your rules.

Cold Brew Coffee to Water Ratio

After measuring the weight of your ground coffee beans (30g for one cup of cold brew), it’s time to add water. 

Cold brew coffee comes to life at a ratio of 1:8. That’s one part coffee beans and 8 parts water. Many cold brew enjoyers swear by this ratio, and we do too. 

That’s not to say that other cold brew ratios like 1:4 or 1:12 are ‘good’ — it’s all a matter of preference. The important thing to understand is that the larger the ratio, the more diluted your brew will be. A cold brew coffee ratio of 1:16 will produce a mix that is ready to drink from the jug to your cup. 

If it’s your first time attempting cold brew, we recommend holding back your adventurous instincts and stick to the 1:8 ratio for now.

Brew Time Required

All that’s left is to leave your cold brew in the refrigerator and allow it to brew on its own. 

With the right coffee-to-water ratio, you can now steep your cold brew for anywhere from a minimum of 8 hours to a maximum of 20 hours. The more time you leave it to steep for, the more flavour you’ll be able to get out of your beans. 

Conversely, being too impatient and ending the brewing process early will leave you with a bitter taste in your mouth, literally.  The same goes for steeping cold brews beyond 24 hours; the bitterness will return to the mix after this long.

Time to Filter Your Cold Brew

Once time’s up, retrieve your cold brew from the fridge and pour the liquid through a coffee filter. Remember to pour slowly and replace the filters when they become too full. 

This step needs to be done carefully unless you like loose bits of coffee grounds in your cold brew.

Perfecting Your Cold Brew Ratio

Finally, pour out half a cup of your filtered mixture into a drinking cup. Why half? Because this mixture (assuming you went with 1:8) is a concentrate and needs to be diluted first. 

As a finishing touch, add an equal part of iced water or milk to the cup to complete your cup of cold brew. 

And there you have it, your very own cup of cold brew coffee! While you savour your brew, we’d like to leave you with some parting tips:

  • Don’t be afraid to experiment with different combinations of beans, roasts, and cold brew ratios to find the perfect formula for your tastebuds. 
  • Remember what cold brew coffee ratio you used — it’ll come in handy at the end when you have to dilute it or scale it. 
  • Use freshly roasted coffee beans to get the most out of your cold brews.

At Bun Coffee, we hand-roast our beans to order and deliver them to wherever you are, whether you’re in Melbourne, Sydney, or on the Gold Coast. Try our fresh roasts and speciality beans in your cold brews for refreshing new flavours!