Grind your beans coarsely, and then measure out the grounds. This goes directly into the bottom of the mason jar.
Fill the mason jar with half a cup of cold water, then stir the mixture, making sure all grounds are wet.
Add the remaining cold water to the mixture in the mason jar and stir again.
Put the lid on the mason jar and place it in the refrigerator. Allow the jar to steep there for 16 to 18 hours. Remember, the longer the steeping time, the deeper the flavors develop. Overnight steeping is suggested if you want your cold brew first thing in the morning.
Once your cold brew has steeped, strain out the grounds using a fine strainer or coffee filter. The purpose of this step is to keep grounds out of your cold brew. This is especially important if you've made a large batch, as you don't want to store finished cold brew with grounds in it.
Your cold brew is ready to serve! Keep in mind that cold brew can taste very strong. Even though it doesn't have any acidity or bitterness, you might still want a more mellow flavor. If this is the case for you, we suggest adding a little more cold water, milk, or half-and-half to your freshly poured cup until it tastes just right.
If you have leftover cold brew, store it in the refrigerator in a clean, airtight container. It will last up to two weeks.