If you’re an all-day sipper, or you just always forget about your morning cuppa until it’s cold, reheating coffee can really alter its flavor, and not for the better. While there are some tricks to minimize this loss of tastiness, some brewing experts recommend something else entirely.
According to some experts, you shouldn’t reheat your coffee at all. Um, what? You need your coffee to be hot, right? Well, turns out, there’s another way to go about it. Instead of a plain old mug, get yourself a large, insulated thermos or to-go mug to keep your brew warm for longer.
Emily Rosenberg, director of education and training operations at Stumptown Coffee, explained to HuffPost that pouring your coffee in a traditional mug will cool it down quickly as it comes in contact with the air. Instead, add your pot to a thermos, and then pour from that all morning (or even into the afternoon).
Why not just use a warmer, though?
Well, it’s because they pretty much do the same thing reheating does. Rosenberg said any brewer or carafe that applies heat will continue to bring out the more bitter and metallic flavors.
Michael Phillips, director of coffee culture at Blue Bottle Coffee, said this happens due to the volatile compounds in coffee. When it’s first brewed, they’re perfectly blended. However, as the coffee continues to heat, this changes.
“When you reheat coffee,” Phillips said, “all of the good stuff in the coffee starts to disappear and the resulting cup leans toward the more bitter components of coffee that stick around through the heating process.”
Along with the suggestion to use a thermos to prevent bitterness, both Phillips and Rosenberg suggest simply brewing more. For those who have easy access to a coffee pot, the pair explained that brewing small amounts will keep it fresh, but it can also be a way to break up a workday.
Not sold on the thermos idea? No problem—there are also some tweaks you can make to your brew when reheating it to keep the bitterness and acidity to a minimum.