There’s no way to rush cold brew. If you’re running a coffee shop, you need to anticipate demand. Every year, that demand is increasing: The United States is becoming a cold-brew nation.
What is cold brew? Essentially, it is a preparation. You steep coffee grounds in room-temperature water (which isn’t “cold,” strictly speaking) for six to 20 hours (depending on the recipe) to make a concentrate that can be diluted with water and served over ice. By giving up heat, you have to add time.
Cold brew is more than a slowed-down version of hot coffee; it’s a noticeably different product. Hot water will bring out the acids in coffee, a characteristic that professional tasters call “brightness.” Cold water doesn’t but still gets the full range of mouthfeel and sweetness. The absence of acidity in cold brew is even more pronounced when compared with the iced coffee from the dark ages (of a few years ago), when it was almost always made with hot coffee that was chilled in the refrigerator. When hot coffee cools, even more acids develop, many of them unpleasantly harsh.
While hot coffee can be volatile, changing in flavor at different temperatures, cold brew is relatively stable, which makes it particularly
well suited to being packaged and sold as ready-to-drink. Boston, Los Angeles, New York, San Diego and San Francisco, sells 20-liter kegs of cold brew and nitrogenized cold brew that are tapped like beer. The kegs have a shelf life of 90 days.