Combine water and coffee grounds in a large jar. Let steep in refrigerator or on countertop for 12-24 hours.
Pour concentrate through fine mesh bag or paper filter into another jar. Discard coffee grounds.
To serve, fill coffee mug or glass with about 1 part coffee to 2 or 3 parts water or nut milk. Serve hot or cold.
Notes
It can be served hot or cold. You can make either a small amount or a large amount and have enough for the week. It will last 7-10 days.**Important! If you are gluten free you may want to avoid coffee altogether. I personally have never had a problem drinking it, and I have a gluten intolerance. It is probably because I drink whole bean organic coffee, and grind it myself. I learned that it can be problematic for people who don't tolerate gluten. So I did some research and one article mentioned to try organic whole bean coffee because it isn't highly processed causing cross-reactivity issues. So please do the research yourself, and test it out. I try to only post recipes that are 100% gluten free since I have a gluten intolerance. I am really careful about avoiding gluten in my daily life.