Gather ingredients - coffee grounds, vessel (canning jar), and mesh insert if using.
If using insert, add grounds to insert, place in canning jar. Add filtered water, cover and allow to brew for 12-24 hrs, either in the refrigerator or on the counter top.
If not using insert, add grounds to jar, add filtered water, cover and allow to brew in refrigerator or countertop for 12-24 hours.
Use a coffee water ratio of approximately 1:8 for cold brewing. If you want to make a concentrate then it would be a 1:4 coffee grounds to water for a concentrated brew. Adjust according to your taste preferences.
Once the steeping period is complete, remove insert or strain the cold brew using either a cheese cloth, cotton kitchen towel, or large paper filter to remove the coffee grounds.
Optional - strain twice to remove residual.