It’s surprisingly simple to make a cold brew at home. All you need is a few kitchen tools, like a mason jar and a strainer.
Making a cold brew with a mason jar is convenient and also gives you a chance to play around with different coffee blends and flavors.
Whether you’re a coffee aficionado or just looking for a simple way to beat the heat, this guide will show you exactly how to make a cold brew coffee in a mason jar.
I also made a video showing you how I make cold brew with a Mason jar. Check it out.
Mason Jar Cold Brew Recipe
- Mason jar
- Scale optional
- 50 grams ground coffee coarsely ground
- 300 ml water at room temp This ratio is for cold brew concentrate. If you are making ready to drink cold brew, add 750 ml of water instead.
- Weigh 50 grams of whole beans and grind it into coarse grind size.
- Grind the coffee beans to the size of the peppercorns and add to the jar. If you are using pre-ground coffee, make sure the grind size is coarse.
- Fill 300 grams of room-temperature water to the jar. Stir and ensure the grounds are fully saturated.
- Steep the ground coffee at room temperature for 16 hours,
- Filter the coffee with a mesh strainer, or cheesecloth.
- Dilute the concentrate with iced water and enjoy! A 1:2 ratio is a good starting point, and you can adjust the strenght as you like.
Cold Brew vs. Cold Brew Concentrate
Cold brew coffee concentrate is much stronger than ready-to-drink cold brew coffee.
Both can be made through the same cold brewing process. You let the coffee ground steep in the cold water for more than 12 hours and strain the coffee out.
The only difference is the coffee-to-water ratio. Coffee concentrate uses a greater amount of coffee, like 1:6. You’ll want to dilute the coffee concentrate with water or milk. While the ready-to-drink cold brew coffee uses a 1:15 ratio, which is similar to the drip or French press coffee.
In the following brewing guide, we are making the cold brew coffee concentrate with a Mason Jar – a really strong coffee concentrate. You’re going to dilute it with water or milk to make more cold-brew coffee.
Things To Know Before You Make Cold Brew Coffee
1. Coffee Grind Size
Since the coffee grounds will be steeped in cold water for more than 12 hours, it requires a coarser grind size. The logic behind this is very straightforward, the more contact time between the coffee and the water, the more extraction. If you use a fine grind to make a cold brew, the coffee will be over-extracted because of such a long brewing time. To check out the right grind size for cold brew, please check out this coffee grind chart.
2. Cold Brew Ratio
Here we will make a jar of concentrated coffee. You can store it in the fridge for a week and dilute it into several cups of cold brew drinks. We will use a 1:6 coffee-to-water ratio, which means we use 50 grams of grounds and get 300 ml (10 oz) of coffee.
If you are making a cup of cold brew that is ready to drink without dilution, the 1:15 brew ratio is good to go. However, do you really want to spend a whole day making one cup of coffee?
3. Brew Time
Normally it takes 12-24 hours to make a cold brew. The longer the steeping time, the stronger coffee you have.
Don’t let the water extract the coffee for more than 24 hours. You may get more bitterness in the coffee. Less than 12 hours, the coffee will be too weak since we are using coarsely ground coffee. 16-18 hours is a good starting point, you can find your own sweet spot based on your taste preference next time.
4. Things We Need
To make a cold brew, you’re going to need five things, a brewer (A mason jar in this guide), a spoon, water, a stainer, and of course, the coffee.
It’s great if you have a coffee grinder so you can ensure the freshness of your coffee. However, if you don’t have a grinder, using the coarse preground coffee you got from the supermarket is totally fine. You can also make French press cold brew if you have one.
5. What Coffee Is Best For Cold Brew
Honestly, all coffee works, but freshly ground coffee beans taste the best.
Just pick your favorite coffee beans. Some coffee lovers prefer lightly roasted coffee. At the same time, some believe the cold brew coffee concentrate should have a richer, darker flavor, so an espresso blend can make a better coffee concentrate.
There’s no right or wrong, but just your taste preference. In fact, cold brew is a very forgiving coffee brewing method, it will cut the bitterness and the adicity of the coffee during the brewing process. So it tastes smoother than coffee brewed with hot water.
Step-by-Step Guide To Make Cold Brew in a Mason Jar
Now you have the basic ideas you need to pay attention to while making cold brew in a mason jar. Let’s get started and make your DIY cold brew coffee at home.
1. Weigh coffee beans (Or preground coffee)
If you have a kitchen scale, weigh 50 grams of whole coffee beans. It’s always recommended to measure the amount of coffee and water so you can make consistent coffee. If you don’t have a scale, use 3-4 tablespoons, or just eyeball it.
2. Grind the coffee beans
Use a coarse grind setting of your coffee grinder to grind the coffee beans. It’s about the size of peppercorns.
Tips: It’s good to use a good burr grinder since it’s challenging to get uniform coarse grounds for some blade grinders. The fine particles will be over-extracted and present unpleasant notes in your final cups.
3. Add water to a mason jar
Pour the water at room temperature into the mason jar.
Since we use 50 grams of coffee, we need to add 300 ml (10 oz) of water using a 1:6 ratio. You can use a spoon to stir the coffee grounds and wet them as evenly as possible.
4. Wait for 12-24 hours
This is the most difficult part. You’d better put the mason jar in a corner and try not to pay attention to it. Leave it there for 16 hours.
5. Decant and Strain the coffee
The next day, remove the lid, and you are going to pour the cold brewed coffee into another mason jar or any decanter through coffee filters. That depends on what you have at home.
If you use a mesh strainer as a coffee filter, there’s gonna be a lot of tiny bits left in your cup, which makes it tastes gritty.
Cheesecloth is a better coffee filter, but it can get really clogged up, especially by coffee grounds. The concentrate you filtered with cheesecloth is still not really clean. You can taste and feel the sediment in your mouth.
And if you think sediment in hot coffee is unpleasant, it’s even worse in a cold drink. If you have a filter paper, that’s awesome. It’s good to filter the coffee again to reduce the sediment.
6. Serve the cold brew coffee
Now we’ve got the cold brewed coffee concentrate, the best bit, it’s time to serve it up.
For a basic black cold brew, take a chilled glass, add some ice, and pour one part cold brew concentrate and then one to two parts cold water. You can adjust the amount of cold water depending on your own preference.
If you like milk, the same thing but we substitute the water for milk. Take a chilled glass, add some ice, and pull one part of the concentrate, then two parts milk or whatever milk alternative you want.
7. Store the rest in the fridge
If you have some coffee concentrate left, screw the lid on the mason jar and store it in the fridge for up to 12 days.
Whenever you need to drink iced coffee, just add some water and milk and enjoy. If you are caffeine addictive as we do, usually a jar of coffee won’t last for 3 days.
Enjoy The Homemade Cold Brew!
That’s how to make cold brew concentrate using Mason Jars at home without any coffee makers. It’s simple, cheap, and very easy to repeat on a day-to-day basis. You can make a big jar of coffee concentrate at the weekend and enjoy cold brew drinks for a whole week. How amazing!
Sure, you can make cold brew following the brew guide above in any watertight vessel you can find in your kitchen, such as Mason jars, a bowl, a glass vessel, or even a plastic container. As long as it is large enough to contain water and coffee.
Both work, you can either make a cold brew in a fridge or at room temperature. However, the brew time should be adjusted accordingly. As colder water extracts the coffee slower, you will need to let it steep for longer if you are brewing in the fridge. In contrast, brewing at room temperature will require less time. We usually recommend extra 3 hours if you make cold brew in the fridge.