Discontent

Fighting Words

A few years ago my wife expressed a preference for iced coffee in the summer, and then as cold brew gained enough in popularity that it started showing up on tap everywhere, she expressed a preference for that over my previous, lazy man's iced coffee method (namely: brew a pot of hot coffee, then immediately put it in mason jars with as little headroom as possible and refrigerate overnight).

I tried all the most common instructions for cold brew on the internet, and I found that no matter what I did I just wasn't satisfied with any of them. I'm not going to call out any specific guides to making cold brew concentrate, but here is what I found:

• It doesn't matter how strong you try to brew the concentrate. If you're making concentrate at all, once you dilute it to drinking strength it just tastes watery.
• On the other hand it's nearly impossible to predict liquid yield based on the starting weight of ground coffee and water, because the amount of water absorbed by the ground coffee and/or trapped between grains after filtering varies. As a result, some dilution is always going to be necessary to hit a target volume without exceeding it.
• There is a point of diminishing or counterproductive returns: longer brewing times increase unpleasant flavor notes.
• Underextraction is also bad.
• The coffee beans that taste best to me when brewed hot don't produce a well enough balanced cold brew. Something slightly darker than that preference tastes better when brewed cold, but since light/medium/dark and city/city+/full city are all basically meaningless when comparing different roasters, this still requires experimentation as availability changes.

Note: I didn't try anything like pressure infusion using a cream whipper and chargers, because it's such a mess to clean up (and if something goes wrong with your cream whipper, as I witnessed at a liquor industry demo, it's even more of a mess). You might be able to make good concentrate under lab conditions, but I was looking for something that was both practical in a home kitchen and delicious.

Here's what I ended up with for one (1) liter of cold brew coffee:

Ingredients

• 114 grams freshly ground coffee (I grind it like I do for French press, but I also grind more finely for French press than most people do). 114 grams seems like a weird number, but it's 4 ounces and most whole bean coffee comes in units of 12 or 16 ounces. I don't recommend pre-ground coffee.
• 1150 ml water at room temperature if your jar or brewer has the room; if your container is smaller, try to get at least 900 ml for best results.

Instructions

• Combine in a large jar or a dedicated cold brew gadget if you have one. I like to add about half the water, let it bloom for a minute or five, then stir down the bloom and add the rest of the water.
• Steep for 12 hours. There's some wiggle room: the safe range seems to be between 11 and 14 hours; much shorter than 11 hours and it'll be weak and acidic; go past 14 and it will start to pick up notes of ash and compost.
• Filter, first through a fine metal strainer and then (if desired) through a paper cone.
• After filtering, check your yield. The coffee will usually trap between 1.6 and 1.7 times its mass in water. If you started with the amounts above you should end up with something between 955 and 970 ml. If you end up with significantly less, check to see if your grounds are still really wet. You can stir them around or try gently pressing on the mass of grounds, but don't use too much force or you'll end up with some flavors you don't want.
• Add a little water as necessary to bring the yield up to 1 liter.
• Chill and serve.

We have an OXO Cold Brew Coffee Maker that takes up a lot of room on the kitchen counter, but it makes the first three steps pretty simple and allows me to make two liters of cold brew at once if I fill it to the top. I fill it most of the way with the “rainmaker” top in place, then remove that and top it off so the liquid comes about ⅛” from the edge, so it doesn't overflow if the coffee continues to bloom. When filtered the yield is usually around 1.75 L. I top it off to 2 L before decanting into a couple growlers (or, usually, a growler and a nitro keg, but that part is entirely optional).

Enjoy. Or, I dunno, keep making cold brew wrong. I'm not your boss.