When Galaxy Girl Coffee started at the local farmer’s market, it was during the height of summer, and no one wanted hot coffee. The question arose as to how we could let our customers sample our wares without dragging out a coffee maker and adding to the heat. We decided to try brewing cold brew. It was not anything we’d done before but figured it couldn’t be that hard. It isn’t, but it is.
As with any good coffee, starting with good beans makes a world of difference. We love our cold brew because we use our Honduras Kingdom Growers beans which have a natural sweetness that contributes to the smooth, refreshing brew. While we have never entered any coffee competitions, the beans have been, and they routinely win cold brew awards. Remember, though, coffee is subjective, so as long as you like it, that’s all that matters.
Next we have the ratio. We use a 9:1 ratio, with nine parts water, one-part beans. We scale everything in grams, so when we are brewing our cold brew, we use a scale to get our brew right.
Our equipment list is easy. It is a kitchen scale that measures in grams, a half-gallon mason jar, coffee beans, grinder, wire mesh strainer, and a paper filter. These are all the items you could have in your kitchen. You can also brew smaller batches in a quart size mason jar. The beauty of mason jars is that they are glass, and the coffee will not leach into the material. You can also see the brew.
We will measure 165 grams of beans and grind them on the courses grind setting on our home grinder. Commercial grinders will have a courser setting, but we don’t want it too course. The ground coffee should be visibly chunky.
This is a key element. For those of you that do not use the kitchen scale for cooking, or haven’t done a lot of science, make sure you tare your scale with the mason jar on it before you put your coffee grounds in it. I usually use a funnel to get the grounds in, so I’ll tare it with the jar and the funnel in place, then put the coffee grounds in the jar.
This is important, because the simple math of adding enough water to bring the total grams to 10x the amount of coffee. For the half gallon mason jar, we will bring the total grams to 1650 for combined water and coffee grounds. For the quart jar, we use 75g of coffee and bring the total grams to 750.
Our shop always labels the jar using masking tape and writing the date and time we started the brew. The goal is to let it brew for 24 hours in the fridge. This will give it that smooth clean taste.
Once the brew time is complete, we use a paper coffee filter in a wire mesh strainer to filter out all of the coffee grounds. This is the most important parts of the process, as leaving any coffee fines (small particles of coffee grinds) in the final product will continue the brewing process, and lead to a slightly bitter brew.
If you want to upgrade your process, you can get a Big Joe’s Coffee maker and use it with the paper coffee filter, which will make it a bit easier to filter directly into whatever vessel you will be storing your cold brew in.
The resulting cold brew concentrate is intended to be cut with water, but it is entirely up to you. If properly stored in an airtight container, it will be good for about two weeks in your refrigerator. As the summer heats up, this will be a great refreshing option to your regular coffee drinking at home.