It’s been close to 100°F for the past couple days, so rather than use my trusty AeroPress to make hot coffee for mid-morning at work (this needs its own post to document the tweaks I use) I made a batch of cold brewed coffee.

Hot brewing heats up the oils and can result in a much more acidic taste that gets bitter as it ages – so unless you plan to drink it immediately over ice, making a large pot of hot coffee then chilling is not going to be great the next day.

Cold brewing is a great alternative to making hot coffee and then cooling it, as long as you remember to start your batch about 24 hours before you want it to drink. Soaking the grounds releases flavors without becoming bitter, and the resulting beverage can be refrigerated for several days without deteriorating in taste.

You can buy many fancy and expensive special devices for cold brewing, but all you really need is a large jar (e.g., a 32 oz mason jar) and something to strain the grounds through, which can be a paper coffee filter lining a mesh strainer.

My recipe:

• I used a 24 oz French Press to make decanting easier,  but any large bottle/container will do.
• Choose a medium roast coffee – dark/espresso/SBux roast will be bitter even done cold.
• Fill the container about a quarter full of fairly finely ground coffee. You can experiment with how much coffee to use – this person suggests 1:1 by volume (e.g., 1 cup coffee grounds to 1 cup water) but I think that’s overkill. I tend to do 1:3 (so fill the container 1/4 full of coffee, then add water to fill)
• I also add some cardamom & allspice (3 tsp cardamom to 1 tsp allspice) to make it like Ula‘s Thai iced coffee, and then add water.
• Stir well (I use a chop stick), wait 10 minutes, stir again.
• Cover the top with plastic wrap or whatever and leave on the counter (not in the refrigerator) for  about 24 hrs.
• Press/strain through a coffee filter into a bottle/pitcher, cover and now refrigerate.
• Then re-add some water to the grounds, stir, wait a bit (30 min to an hour is fine), strain again into a measuring cup or something out of which you can pour (not the same container as your first press coffee).
• mix this 2nd generation coffee with some sweetened condensed milk and pour into ice cube trays for “Vietnamese style” ice cubes. When they are frozen you may wish to store them in a closed container or plastic bag to keep from absorbing other food odors.

Since the 1st press coffee is pretty strong, in a 12 oz travel mug I add a few coffee ice cubes, about 5 oz of the coffee, and then milk to taste.

You can also heat up the cold brew with some additional water in a microwave to make a hot Americano, Just be careful not to boil! If you know how long it takes to boil a cup of cold water, set the timer for 75% of that duration.

June 2014 bonus info!  Check out Kent Brewster’s blog post detailing how to make better-tasting hotel room coffee by using the in-room coffee gear to make cold brew instead!