Cold Brewed Coffee

With summer upon us, it’s time to think about ways of getting your daily caffeine intake without having to endure a hot drink! Enter iced or cold brewed coffee. Over the past few years cold brewed coffee in particular has become increasingly popular, with many brands now producing ready made cold brew. In this article we take a look at some methods of producing cold brewed coffee at home, and some of the kit you can buy if you want to explore further. 

The principle of cold brew

When you make a coffee at home, you are using water to dissolve coffee solids. As it stands, water is pretty poor at dissolving solids so we have to give it a helping hand. We do this for the most part by heating up the water but we might also use pressure (when we make espresso), and we might also stir or agitate the coffee. As there is no heat involved when it comes to cold brewed coffee, we have to help the water in another way; essentially we use time to compensate for the lack of heat. Most cold brews require 8 to 24 hour brew times in order to dissolve enough solids. So the first rule of cold brewed coffee is to plan ahead!

Which coffee is best to use for cold brew?

A lot of people suggest darker roasts will produce the best cold brews. This might be due to darker roasts being more soluble and therefore reacting better to the cold water. Our advice is to experiment. We have tasted some delicious cold brews using light to medium roasts.

What grind setting should I use?

It is always difficult to be specific about grind settings as it is just one variable to consider. You can never beat trial and error when it comes to determining a grind setting. Given the longer brew times we’d suggest a coarser grind for darker roasts but perhaps a medium grind for lighter roasts.

The recipe: coffee to water ratios

A ratio of 1 part coffee to 5 parts water is a good starting place and then you can adjust to taste, using more coffee for a stronger brew and vice versa.  Some of the methods outlined below use ratios of around 1:12 which will produce a lighter brew depending on steep time.

It is common to make cold brew as a concentrate and dilute with either 4 parts cold water or a milk of your choice. 

How long does cold brew last?

All coffee starts oxidising once brewed but cold brew has a much longer shelf life than hot brewed coffee (which tastes terrible if allowed to cool). After 2-3 days in the fridge you might start to detect that your brew is starting to loose its quality but again personal preference has to play a part.

Method 1: Immersion Cold Brewing

Immersion cold brewing is simple yet effective. Mix coffee and water, ensuring the grounds have been fully saturated, and allow to brew for 8 to 24 hours. There are a number of options when it comes to kit for this method:

You can make cold brew in a cafetiere or coffee press. Simply mix your water and coffee together thoroughly to ensure all the grounds are fully wet, and then brew for around 12 hours in the fridge. Depending on whether you can deal with sediment in your coffee, you can either pour the cold brew straight through the cafetiere strainer or pour it through a paper filter for a cleaner finish.

Hario make a striking cold brew bottle which makes the process clean and easy. You make and store the cold brew in the same bottle. The internal filter allows the coffee to steep in the water and a strainer allows you to serve directly from the bottle. 

For larger batches (up to around 1.9 litres), the Toddy Cold Brew System is a great option. Brew your coffee (or tea) in the upper chamber and then drain through a reusable felt filter into the serving vessel.

For a quick cold brew option, try an Aeropress. This method is likely to work better with darker roasts and finer grinds. The video below from Aeropress themselves explains the 2 minute cold brew method.

Option 2: The Drip Method

Cold brewed coffee can also be made by slowly dripping water through a bed of coffee. Typically 1 drip of water should hit the coffee bed every second and once the bed is saturated, the coffee will begin to drip into a lower container. It takes around 2-3 hours to brew coffee in this way.  The Dripster is one of a number of brands which work on this principle.

How is cold brew different to an iced coffee?

Cold brewed coffee is made using cold water, an iced coffee is a hot brewed coffee which has been chilled straight away usually by pouring over a glass of ice. There are two common options when it comes to producing iced coffee, both working on the principle of chilling the coffee instantly.

The first requires an espresso machine and it is simply a case of pulling an espresso shot straight into a glass of ice. Alternatively pull the espresso shot into a glass of iced milk (a milk of your choice combined with ice cubes) to create an iced latte.

Alternatively you can produce an iced filter coffee using the method below which has been developed by James Hoffmann. 

Cold Brewed Coffee via @carvetiicoffee

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