How to Make Cold Brew Coffee

Grind 1.5 cups (80g) of beans to a coarse texture - aim for something close to coarse cornmeal or kosher salt. Anything finer turns muddy and bitter during the long steep, and a paper filter will clog if the grind is too fine.

Use freshly roasted beans if you can. Joshua notes that some sites say older coffee tastes better for cold brew, but that is up to your palate.

Tip the ground coffee straight into a half-gallon wide-mouth mason jar. The wide opening makes it easy to stir and to strain back out later, and the screw lid seals tight enough for a fridge full of grounds and water.

Half-gallon Ball jars come in packs of six and are cheap. They are the same jars you'd use for canning, infusing, or batch cocktails - worth keeping a few around.

Pour in 6 cups (1400g) of cold or room-temperature filtered water. Filtered matters - whatever is in your tap water ends up in the cup, and chlorine flavors come through clearly in cold brew. The water just cannot be hot.

That works out to a roughly 1:17.5 ratio of coffee to water by weight. It produces a balanced, drink-as-is cold brew rather than a concentrate, so you can pour it straight over ice with a splash of milk.

Stir the jar with a long spoon for ten or fifteen seconds. You want all the grounds fully soaked - dry pockets floating on top will not extract, and you'll end up with weak coffee.

The mixture will look like swampy black water. That is correct.

Screw the lid on and put the jar in the fridge. Walk away for at least 12 hours.

Twelve hours gives a lighter, more tea-like brew. Twenty-four hours gives a much stronger, more concentrated cup. If you are not sure where you land, start with 18 hours and adjust the next batch based on taste.

Set a fine mesh strainer over a clean pitcher or large bowl and lay a piece of cheesecloth inside it. Pour the cold brew through slowly so the grounds settle without splashing.

This method is fast but can leave a little sediment in the cup if your grinder produced fine particles along with the coarse ones. If your grinder is inconsistent, skip ahead to the Chemex method in the next step.

For a completely grit-free cup, run the brew through a paper filter in a pour-over device like a Chemex. The paper traps every speck of sediment no matter how uneven the grind was.

It takes longer than the cheesecloth method - the filter slows everything down - but the result is glassy clear and noticeably smoother on the tongue. A reusable cotton filter like a CoffeeSock works the same way without the disposable paper.