Mason Jar Cold Brew: The Quart Jar Recipe That Needs No Special Gear
Mason jar cold brew: 1 and a quarter cups of coarse ground coffee, 3 and a third cups of cold water, a quart jar, and 12 to 18 hours. Strain through a coffee filter. Done.
No press, no gadget, no cold brew system from a late-night ad. Here is the recipe with the details that keep it from tasting sour or muddy.
15W40 for smooth and chocolatey. Cavalry if you want extra caffeine.
Dark roasts turn into rich, low-bitterness cold brew. 15W40 tastes like chocolate and caramel. Cavalry blends in Robusta for more caffeine with a chocolate and bourbon finish. One 12 ounce bag fills about three quart jars.
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What is the mason jar cold brew ratio?
For a 32 ounce (quart) mason jar:
| Strength | Coffee | Cold water | Makes |
|---|---|---|---|
| Ready to drink (1:8) | 100 g, about 1 1/4 cups coarse | 800 g, about 3 1/3 cups | About 20 oz |
| Concentrate (1:4) | 160 g, about 2 cups coarse | 640 g, about 2 2/3 cups | About 11 oz, doubles when diluted |
Using a pint jar? Cut everything in half.
How do you make cold brew in a mason jar?
- Add 100 grams of extra coarse ground coffee to a clean quart jar.
- Pour in about half the water and stir hard, or put the lid on and shake. Every ground needs to get wet.
- Add the rest of the water. Leave about an inch of space at the top.
- Lid on. Steep 12 to 18 hours on the counter, or 18 to 24 in the fridge.
- Line a strainer with a paper coffee filter over a bowl. Pour slowly and let gravity work. Do not squeeze.
- Rinse the jar, pour the cold brew back in, and refrigerate.
Shortcut: fill a nut milk bag or a reusable mesh coffee sock with the grounds and drop it in the jar. Pull it out when time is up and skip straining entirely.
Why does my mason jar cold brew taste sour?
It is under-extracted. The usual causes are a grind that is too coarse for your steep time, not enough time, or brewing in a very cold fridge. Give it a few more hours or steep it on the counter.
If it tastes bitter or woody instead, you went too long or too fine. Stop at 18 hours and go coarser. The full troubleshooting chart is in our complete cold brew guide.
Can you leave cold brew in the mason jar with the grounds?
Not past about 24 hours. The grounds keep extracting, and flavor turns harsh. Strain it, rinse the jar, and store the finished cold brew by itself. Strained cold brew keeps well in the fridge for about a week, and here is how long it lasts after that.
How much does mason jar cold brew cost?
One 12 ounce bag makes roughly three quart jars, which is around eight or nine glasses. At $16.99, that works out to about $2 a glass, and less when you subscribe. The jar you already own.
What else can you do with the jar?
- Vanilla cold brew: drop a split vanilla bean in while it steeps.
- Cinnamon cold brew: add a cinnamon stick. Strain it out with the grounds.
- Salted caramel: here is the recipe.
- Fake nitro: shake cold brew hard in a half-full jar for 30 seconds for a foamy top.
Keep the jar full
Set 15W40 or Cavalry to ship every 2 or 4 weeks so the next batch is always ready. First subscription order is 30% off automatically, 15% off every delivery after, change or cancel anytime.
Subscribe to 15W40All dark roastsQuestions people ask
How much coffee do I put in a mason jar for cold brew?
For a quart mason jar, use about 100 grams, roughly 1 1/4 cups, of extra coarse ground coffee with 800 grams, about 3 1/3 cups, of cold water for ready-to-drink cold brew.
How long do you steep cold brew in a mason jar?
Steep 12 to 18 hours at room temperature, or 18 to 24 hours in the refrigerator, then strain through a paper coffee filter.
Can you brew coffee in a mason jar?
Yes. A mason jar is one of the easiest ways to make cold brew. Add coarse grounds and cold water, steep, then strain through a coffee filter or use a mesh coffee sock inside the jar.
How do you strain cold brew without cheesecloth?
Pour it through a paper coffee filter set in a strainer or pour over cone. Pour slowly and let it drip rather than squeezing, which keeps bitterness and grit out.
How long does mason jar cold brew last?
Once strained, cold brew tastes best within about a week in the refrigerator. Keep it sealed, and toss it if it smells off or sour.
