Cold-brewed coffee was made popular by the Toddy system in the 1960s, and has been enjoying resurgence of late. The Toddy system was invented in 1964 by Todd Simpson, a chemical engineering graduate of Cornell University. According to the Toddy company, cold-brewed coffee made using regular coffee beans results in coffee that has 67 percent less acid than hot-brewed coffee.
Unlike regular iced coffee, which is brewed hot and served over ice, cold-brewed iced coffee is brewed cold or at room temperature, which offers a noticeably different coffee experience. In addition to being less acidic (and in part as a result of the lower acidity), cold-brewed coffee has a sweeter, smoother flavor than hot-brewed coffee, and also has a higher amount of caffeine.
Coffee beans have a number of oil compounds and acids known as “solubles,” which are pulled from the bean during the brewing process. These solubles are most efficiently drawn from the coffee beans at temperatures of around 195 to 205 degrees Fahrenheit. Because those temperatures are highly efficient at pulling the solubles from the coffee beans, hot-brewed coffee tends to be more aromatic and have a full-bodied flavor. However, the high heat also has the negative effect of causing the solubles to oxidize, leading to a sour taste, and the acids tend to degrade, which increases the bitterness of the coffee.
The slow, cold brewing of coffee eliminates the downsides of the heat in the brewing process, and also leaves some of the more objectionable tasting compounds in coffee in the grounds. This leaves you with a much sweeter, smoother flavor profile to the coffee.
The lower acidity of cold-brewed coffee is easier on the stomach, and can also mean less damage to tooth enamel. Our bodies are also sensitive to pH balance, and prefer a more alkaline state. The high acidity of hot-brewed coffee can cause our system to become more acidic, and as a result we sometimes don’t feel well after drinking a lot of coffee, despite the otherwise uplifting effects of the caffeine. Cold-brewed coffee can be an excellent option for people who otherwise tend to avoid coffee because of acid reflux or other digestive issues.
Cold-brewed coffee doesn’t go stale as quickly as hot-brewed coffee (which is usually past the point of drinkability after a day), so it can be stored in the refrigerator and consumed over time without losing its rich flavor. For those of us who would like to simplify our mornings, cold-brewed coffee can be made in larger batches ahead of time and stored in a sealed container in the refrigerator for up to a week. All we need to do for our coffee fix before we head out the door is to pour it over ice, or quickly heat and pour it in a cup. If your cold brew comes out stronger than you prefer, just add a bit of cold water to the brew.
How to Make Cold Brew Coffee
With cold-brewed coffee, you’ll want to use more ground coffee relative to the amount of water than you would use with hot coffee. For cold brew, a good rule of thumb is to use one part ground coffee to four parts water. So one cup of coarse ground coffee to 3 cups of water will make a nice batch. Using a coarse grind will make the coffee easier to filter, and will prevent too many solids in the filtered coffee, which can make the coffee more bitter.
Put about half of the water in a large mason jar or a bowl, and put in the ground coffee. Then pour the rest of the water over the top, and stir well. It is important that all of the ground coffee is wet and mixed well with the water.
Let this mixture set to brew at room temperature for 12 to 24 hours, and then run the coffee through a coffee filter and a funnel into another container. Chill the cold brewed coffee in the refrigerator for two to three hours, and then serve over ice. Cold-brewed coffee can also be heated if you prefer to drink your coffee hot. The filtering process can also be simplified by enclosing the ground coffee in coffee filter paper or cheese cloth before submerging the ground coffee in the water.
You can also use a French press to make cold brew. If you use the French press, once you have put in the ground coffee and the water and mixed well, it is a good idea to press down the plunger just slightly for brewing, which will keep the ground coffee under the surface of the water for optimal brewing.
Nitro-Kegged Cold Brewed Coffee
Nitro-kegged cold brew has become wildly popular in the hipster coffee shops of late. If you love iced coffee, and you’ve never had nitro-kegged cold-brewed coffee, you are seriously in for a treat. Nitro-kegged coffee is kegged and served from a tap in the same way as a nitro-kegged beer like Guinness. It has that same creamy mouth feel and a nice, rich foamy head as a freshly tapped pint of Guinness, but with plenty of caffeine, and no alcohol. The coffee is cold-brewed first, then inserted into the keg. The keg is then sealed and pumped full of nitrogen for 24 hours, then is hooked up to the same kind of tap you would use to serve beer. Some people include both nitrogen and CO2 in their “carbonation” of the coffee. The amount of nitrogen and/or CO2 added to the coffee definitely changes the flavor, so it is worthwhile experimenting with those levels.
Nitro Coffee with a Whipped Cream Maker
If you want to try nitrogen infused cold-brewed coffee at home and don’t want to go to the trouble of investing in a keg system, another option is to use a whipped cream dispenser.