Making Cold Brew in a Mason Jar-Why it is the best technique
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After testing several variations of making cold brew coffee, it turns out the simplest one is my favorite. All you need is coffee, water, coffee filters, and a mason jar and I’ll bet you have all 4 in your house already.
Making coffee in a mason jar is as simple as it gets. You put coffee grounds in the jar, fill it with water, put a lid on it, and let it sit on your counter for 12-24 hours. At the end of the brew time, strain the mixture through a coffee filter (or coffee bag) and enjoy.
Step by step:
You will need:
- A mason jar with a lid
- Coffee
- Water
- Filter paper or coffee bag
- Filter cone for paper filters, a mesh sieve can substitute if you are using a coffee bag.
- Fill a mason jar about 1/4 to 1/3 full of coffee grounds. Coarsely ground or medium coarse is best. I use a “pint” for one serving or “quart” sized jar for 2 servings.
2. Add enough water to wet the grounds. Give it a swirl to make sure all grounds are wet, then fill the rest of the jar with water. Place it in the fridge.
TIP: Once or twice, give it a swirl to make sure all the grounds are contacting the water. Sometimes the grounds like to float on top but you will get better extraction if you make sure the grounds are well circulated in the water.
3. Brew in the fridge for 12-24 hours (14-20 seems to be the sweet spot but don’t get hung up on time). Pour the coffee through a filter. I use a paper filter in a pour over holder. You can also use cheesecloth, or a filter bag.
Optional: Dilute with additional water to taste.
And that’s it really. There is no excuse for not making delicious cold brew in your home. How many coffee trends can you say that about?
What are the advantages of this method?
The reasons why this method is my favorite are:
- Simple and doesn’t require specialized equipment
- No off flavors from soaking the grounds in a cloth coffee bag
- Using a coffee filter makes clean up easy as I can just toss the whole works, filter and grounds, in the compost bin
- After straining, I rinse out the mason jar and pour any leftover coffee back in the jar for storage in the fridge
Another thing I like is mason jars can withstand heat. Now, you may say why is that important? Because mason jars can be washed in the dishwasher. This means your container is sanitized with pretty hot water in between uses.
Remember, with cold brew we are letting water sit on the counter for up to 24 hours. Nasty things can grow in water. The good news is to grow, they need to be introduced to the system first. Using very clean equipment is one safeguard to keeping your brew safe.
You may see some sources say to brew at room temperature. I started out this way, but I am a stickler for food safety so now I only brew on the countertop if it will take less than 2 hours to brew (e.g. rapid cold brew makers, or cold drip coffee makers)
Are there any downsides?
- Paper filters may introduce some off flavors to the coffee, however in my experience this has not been the case. This can be a complaint when using paper filter with hot coffee, however I believe that the low temperatures combined with short contact time make this problem negligible in cold coffee.
- Paper filters can absorb some of the coffee oils. Using a cheescloth or cloth coffee bag allows more of these oils to pass through.
