Reheating coffee can significantly alter its flavour, and not for the better, if you drink it throughout the day or forget about it until it’s cold. While there are techniques to minimise this loss of flavour, some brewing experts recommend an entirely different approach.
According to some experts, you should never reheat coffee. What the…? You need your coffee to be hot, correct? Evidently, there is another approach. Instead of a regular mug, invest in a large, insulated thermos or travel mug to keep your beverage hotter for longer.
Emily Rosenberg, director of education and training operations at Stumptown Coffee, explained to HuffPost that pouring your coffee into a traditional mug will rapidly cool it as it comes into contact with air. Instead, transfer your pot to a thermos and pour from that throughout the morning (or even into the afternoon).
Why not use a warmer instead?
Because they perform essentially the same function as reheating. Rosenberg stated that any brewer or carafe that applies heat will continue to accentuate bitter and metallic flavours.
Michael Phillips, director of coffee culture at Blue Bottle Coffee, explained that this is due to the volatile compounds in coffee. They are perfectly blended upon initial brewing. This, however, changes as the coffee continues to heat.
“When you reheat coffee,” said Phillips, “all the good stuff in the coffee begins to evaporate, and the resulting cup is dominated by the bitterer coffee components that survive the heating process.”
In addition to using a thermos to prevent bitterness, both Phillips and Rosenberg recommend brewing more coffee. For those with easy access to a coffee maker, the pair explained that brewing small amounts of coffee will keep it fresh and can also serve as a way to break up the workday.
Not convinced by the thermos? There are also some adjustments you can make to your brew when reheating it to minimise bitterness and acidity.