Cold brew, cold press, or toddy coffee refers to the process of steeping coffee grounds in room temperature or cold water for an extended period.
The cold-press process requires grinding: coarse-ground beans are soaked in water for a prolonged period of time, usually 12 hours or more. The water is normally kept at room temperature, but chilled water can also be used. The grounds must be filtered out of the water after they have been steeped using a paper coffee filter, a fine metal sieve, a French press or felt in the case of the Toddy system. The result is a coffee concentrate that is often diluted with water or milk, and can be served hot, over ice, or blended with ice and other ingredients such as chocolate.
Cold brewed coffee naturally seems sweeter due to its lower acidity. Because the coffee beans in cold-press coffee never come into contact with heated water, the process of leaching flavor from the beans produces a different chemical profile from conventional brewing methods. There are also high levels of caffeine in a cup of cold brewed coffee compared to hot brewed coffee.
Cold brew coffee is not to be confused with iced coffee, which generally refers to coffee that is brewed hot and then chilled by pouring over or adding ice, though iced coffee can refer to cold brew coffee served on ice.