The homebrewing community had a bit of a discussion about it a few weeks back, and I gamely gave it a shot as I said I would. Below is the method I used and thoughts.
-.5 lbs coarse ground coffee (darker roast works best)
-5 cups of room-temp water
Combine in a pitcher or bowl, and let sit for 12+ hours. (I did mine for about 18 I think, just how my weekend went.)
Strain coffee grounds out. (more on this later)
You should have 3-4 cups of coffee extract now. Put it in a mason jar in the fridge, should keep for at least a few weeks.
Mix one part extract with 3-4 parts cold or hot water. Drink.
(If you like milk in your coffee, do 1 part extract, 1 part milk, and 2-3 parts water.)
This is one of the best parts, coffee exactly when you want it. Grab the extract, add water, coffee. Tada!
- Straining the grounds:
This part is the sucky part.
I had decent success doing a preliminary strain through a standard colander, then lining a sieve with a coffee filter, and pouring the extract through there. Downside was that it took a good half-hour or longer.
Next time I'm going to try cheesecloth.
- Flavor thoughts:
I used an Ethiopian bean that I like a lot when hot brewed, because it makes a full-flavored but mellow coffee. As a cold-brewed coffee it's a whole lot smoother and mellower. You get a lot more depth of flavor than you get when you hot-brew it. It's missing the 'edge' that hot-brewed coffee has, which is great for my tummy which don't appreciate acid much. I think this is what a lot of people mean when they say that cold-brewed coffee tastes weak.
I don't find it week, it's just a less harsh flavor profile with a lot more nuance.
prosicated, a life-long coffee hater and tea-geek, took one sip and said "holy shit, I'll happily drink that!"
I proclaim it awesome.