Cold brew and iced coffee can taste just fine, as does hot brewed stuff. So, why does hot coffee that's been allowed to cool usually taste so awful?

How to use a Styrofoam cup to protect your pipes First, be sure to poke a hole in the bottom of the cup. Use some kind of cord, like a rubber band, through that hole.

According to Kelley, when you first pour a hot cup of coffee, the insulation keeps it from burning your hands. Those properties also work in reverse.