Cold brew at home. A comprehensive guide.

The days are getting hotter (Yay!) and we will soon be craving our favourite refreshing cold brew coffees - I know I already am! I will go through the most popular methods for making cold brew coffee, discussing the differences and help you choose the right brewing method with the right bean for you. 

The immersion method, Japanese style cold brew and Slow drip cold brew are three of the most popular methods for making cold brew. I have tried a lot of coffees through most cold brew methods and can guide you with my recommendations to help you get your home cold brew just right. 

Immersion Method 

The immersion method is essentially steeping coarsely ground coffee in cold filtered water overnight.

If you would like to try the immersion method there are two things we’ll have to consider - the brew time is very long and therefore you will need to have a rather coarsely ground coffee - roughly the size of small dried peppercorns. The second significantly different factor is the temperature of the water (use filtered water where possible). The cold water extracts flavours from the coffee in a slightly different way than hot water - it is a much gentler process and therefore you would need more coffee per 100ml of water. Rounded coffees with pronounced chocolatey flavours will generally work better for this brew method, but do experiment with your favourite beans.

For this recipe I used our Knockout blend and brewed it in ratio 1:12.5 (10g coffee : 125 ml water) for 17 hours. 

Put 60g of coarse ground coffee in a vessel (I used my caffetiere), top it up with 750ml filtered cold water, cover with cling film and put in the fridge. Let it brew for 17 hours (if you do it in the early afternoon it will be ready for you when you wake up). In the morning strain the coffee grinds and enjoy. I drink my coffee black, but you can add milk, or any other flavouring of choice. 

You will end up with a very smooth and sweet cup with a slightly boozy note.

Japanese style cold brew

the Japanese style cold brew is a lot quicker, as the coffee is being brewed with hot water and over ice for immediate cooled down drink. For this method, I find lighter and fruitier coffees to work better. Try the Kayon Mountain or the El Cautivo La Coipa as they would work really well.

I would use the same ratio coffee to water as your standard filter (about 30g of coffee for 500ml of water). The difference here is that we will substitute 40% of the water with ice (put the ice in the vessel you will brew the coffee into).

The result is a very sweet and fruity cup with juicy body. Very refreshing and clean.

Slow Drip Cold Brew

For this method you would need a special brewing device, composed of a water reservoir connected to a valve that slowly lets the water drip over the coffee grounds. The water then drains through a filter into another vessel that collects the cold brew (Do let us know if you would be interested in us stocking cold brew coffee brewers).

It’s important to get the balance of grind size to drip speed right for this brew method.

I would recommend using a medium coarse grind - similar to large grains of sand, and aim for one drip per second. One thing to keep in mind if you would use a slow drip - as time goes, you will have less water in the top reservoir, the drip speed will slow down as there is less weight pushing the water down. You would have to adjust the drip rate a few times during the brew time to keep it consistent. For this recipe I would use 12g of ground coffee per 100ml of water.

Put the grounds in the coffee compartment, fill the water reservoir (filtered cold water) adjust the drip rate and wait.

The result is bright, sweet, fresh cup. Not as full bodied as you would get from the immersion cold brew, but much cleaner.

As always the most important factor to remember is to experiment with the recipes and enjoy your brews! I would love to see photos of your cold brews and recipes - tag @olfactorycoffee on instagram!


Mariya x

Head Roaster at Olfactory Coffee Roasters