Cold Brew vs Iced Coffee: The Real Difference

People use cold brew and iced coffee as if they mean the same thing. They do not. The two are made by completely different processes, and that difference shows up in taste, strength and shelf life. Here is what separates them.

Iced coffee: hot brew, then chilled

Iced coffee is exactly what it sounds like. You brew coffee hot, the normal way, and then cool it down over ice. Because it was brewed with hot water, it extracts quickly and keeps the bright acidity and aromatic complexity of regular coffee. The downside is dilution, as the ice melts into a coffee that was not made to be watered down, so good iced coffee is often brewed stronger to compensate, or chilled rather than poured straight onto a full glass of ice.

Cold brew: cold water, lots of time

Cold brew never sees hot water. Coarsely ground coffee steeps in cold or room-temperature water for a long time, typically 12 to 24 hours, then gets filtered. Without heat, extraction is slow and selective. It pulls out plenty of caffeine and sweetness but far fewer of the acidic and bitter compounds that heat releases.

Why they taste so different

Heat is the key variable. Hot brewing extracts acids and aromatics that make coffee bright and lively, which is why iced coffee tastes like a chilled version of a normal cup. Cold brewing leaves most of those acids behind, producing a smooth, mellow, naturally sweet, low-acidity drink. If regular coffee bothers your stomach, cold brew's low acidity is often easier to handle.

Strength and concentrate

Cold brew is usually made as a concentrate, using a high ratio of coffee to water, then diluted to taste with water, milk or ice. That makes it flexible and often higher in caffeine per serving, depending on how you dilute it. Iced coffee is generally brewed at normal strength and served as is.

Keeping and making them

• Cold brew keeps well in the fridge for up to about two weeks as a concentrate, which makes it great to batch.
• Iced coffee is best fresh, since it loses aroma quickly once brewed and chilled.

To make cold brew at home, steep coarse grounds in cold water overnight at roughly one part coffee to four parts water, then filter and dilute. For iced coffee, brew a strong hot cup and pour it over plenty of ice, or chill it first. Two methods, two very different drinks, both excellent in summer.