When I decided to throw a weekend brunch for my book club, the one aspect of the party that was a big question mark was the coffee. Ever since I ditched my drip coffee maker for a Chemex, making coffee for more than four people has meant a lot of me standing around in the kitchen slowly pouring hot water over coffee grounds while everyone else is having fun in the other room. I didn't want that to happen at this party.
Instead I experimented with using a coffee concentrate — the same type I had used in the past to make stellar iced coffee — and discovered the process turns out a cup of hot coffee that is just as good: rich, flavorful and mellow. Even better, making a pot of coffee for a crowd of people with this method is literally as easy as boiling water.
Making a cold-brew coffee concentrate doesn't require any special equipment, just a big bowl or pitcher to hold the grounds and water while they steep, and a filter-lined strainer to drain the resulting liquid. I was concerned that the cold concentrate, which is kept in the refrigerator, would make the resulting cup of coffee lukewarm, so I tweaked my usual recipe to make it slightly more potent. This meant I could dilute the concentrate with two parts hot water, instead of using a 1:1 ratio. Not only did this result in a hotter cup of coffee, it was one I found even more rich and flavorful.
I made the concentrate a couple days before the party, so all I had to do on the morning of the brunch was bring some water to boil and combine it with the concentrate in a thermal carafe. When I mentioned how I had made the coffee midway through the party, all of the guests were surprised, and the die-hard Chemex and Aeropress fans in particular were asking for instructions. I am assuming they, like me, hate to trade the great taste of their morning coffee for a less time-intensive but inferior-tasting method when making coffee for a crowd. And with this method, we don't have to.
Stir to make sure all the grounds are wet. Cover with an old tea towel and let sit on the counter for 24 hours.
How To Make Coffee Concentrate to Serve Coffee to a Crowd
Makes about 1 quart of concentrate (about 3 quarts brewed coffee)
What You Need
12 ounces coffee, coarsely ground 6 cups water (plus more for serving)
Equipment 2 large bowls or pitchers Kitchen towel or cheesecloth Sieve Large coffee filter Covered container to store concentrate (such as a quart-size canning jar)
Steep the coffee overnight. Place the ground coffee in a large bowl or pitcher and cover with 6 cups cold or room temperature water. Stir to make sure all the grounds are wet. Cover with a tea towel and let sit on the counter for 24 hours.
Strain the coffee concentrate. Place the sieve in the other large bowl or pitcher. Wet the coffee filter and use it to line the sieve. (I use an unfolded Chemex filter paper in these photos. A large filter for urn-style coffee makers would also work.) Carefully pour the coffee and grounds into the sieve, stopping whenever it gets too full. Let sit undisturbed until there is no more liquid dripping through the sieve, which can take 30-45 minutes. You will have about one quart of liquid.
Transfer the concentrate to a covered container. Discard or compost the grounds. Pour the strained coffee concentrate into a covered container for storage.
Store the concentrate in the refrigerator for up to one week.
Dilute the concentrate with 2 parts boiling water. When you're ready to make coffee, bring the appropriate amount of water to a boil. I like the ratio of 1 part concentrate to 2 parts water, but you can experiment to see what tastes best to you. Pour the concentrate into a carafe or thermos. Slowly add the hot water and serve.
If you would like to start with a different amount of beans, use a weight ratio of 1 part coffee to 4 parts water. (So 16 ounces of coffee beans would use 64 ounces, or 8 cups, of water.)
The concentrate can also be used to make iced coffee. Dilute the concentrate with 2 parts cold water and serve over ice.
Of course, you don't have to use the concentrate to serve a crowd. Just use the ratio of 1 part concentrate to 2 parts boiling water to make as much or as little coffee as you want.