As coffee loses heat, it not only feels cooler, but it tastes more bitter, which is why room-temperature coffee can be so unpleasant. You might think the best way to restore your coffee is to put your mug in the microwave for a quick reheat, but the best way to go about it is to return the coffee to the stove.

Radiation inside a microwave can cause coffee's natural, volatile compounds to be released, thereby giving the drink even more of that bitter, burnt taste. Instead, the best way to reheat your coffee is on the stove over low heat, as the lower heat helps to preserve whatever aromas and flavors your coffee has left.

You'll know your coffee is back up to heat when wisps of steam start dancing off the top of the liquid or out of the kettle spout (to be specific, you're looking to hit between 120 to 140 degrees Fahrenheit on a food thermometer.) Be sure to keep the heat low and exercise patience, lest you burn your coffee.