Little is as annoying as a cup of coffee gone cold, but one trick to keeping it hotter longer might surprise you: Add cream. As paradoxical as it sounds, adding some cream to a hot coffee prevents it from getting cold as quickly as a cup without cream. Sure, the cream drops the temperature of the coffee quickly at first, but it more than makes up for the initial heat loss in the long run.
First, darker things emit heat fastest, and since adding cream makes black coffee lighter-colored, your cup will retain the heat better. Second, the cream makes the surface cooler, which prevents it from losing heat as quickly as a hot surface. And finally, cream is a viscous liquid, which holds heat better than non-viscous liquids (like coffee), so adding it to your coffee slows the overall loss of temperature. Generally speaking, coffee with cream loses heat at a rate 20 percent slower than black coffee.
More coffee surprises:
- One 8-ounce serving of brewed coffee has more caffeine than a 1-ounce serving of espresso.
- Lighter-roasted coffee actually contains more caffeine than darker roasts.
- Finland doesn't produce coffee, but its residents drink more of the stuff than anyone else in the world.