Can You Reheat Coffee in the Microwave?

It’s happened to every coffee drinker– you get the first few all-important sips in while it’s still hot, only to set it down and be left with a tepid cup of joe next time you need a pick-me-up. 

If you need to reheat coffee but don’t have access to a full kitchen, you can reheat coffee in the microwave using the “defrost” setting. 

Reheating Coffee in the Microwave

Everybody has microwaved their coffee at least once in their java-drinking lifetime, and just as many people have been disappointed by the results. It never seems quite the same as a fresh cup of coffee, but there is a method of reheating coffee in the microwave that gets it pretty close to a fresh drip:

  1. Not all mugs are microwave-safe, so first, ensure the coffee is in a microwave-safe mug or container. 
  2. Place the coffee in the microwave and heat for one minute using the “defrost” function, which is a reduced power setting. 
  3. Carefully remove the coffee from the microwave, stirring gently, and repeating the process until your desired temperature is reached. 

This method of gradually reheating coffee in the microwave is preferred over nuking it at full power for a few minutes if you have any sort of creamer in your cup that could potentially curdle at high temperatures. 

Alternate Methods of Reheating Coffee

If you have the time and want to preserve the coffee’s initial integrity as much as possible, you can always try reheating your coffee on the stovetop. This is typically regarded as the best way to reheat coffee.  To do so:

  1. Pour cold coffee into a small pot. Using too large of a cooking vessel could lead to the coffee evaporating and burning. 
  2. Turn the stove to medium-low heat, never allowing the coffee to boil. 
  3. Stir occasionally, carefully removing the pot and pouring coffee into a mug once it has reached your desired temperature. 

Slow and low is the way to go regarding reheating coffee. Getting it too hot too quickly will accentuate any brew’s bitter, acidic elements.

Why Does Reheated Coffee Taste Different?

Coffee is made out of roasted coffee beans. This process of roasting beans is what unleashes all of the complex favorites present in your morning (or afternoon, or evening) cuppa. That is to say, all of the flavor components that make up a cup of coffee are heat-activated. Though coffee can have fruity or chocolatey undertones, the bitter and acidic elements are what come through the strongest. The longer you heat coffee, the longer these bitter and acidic elements have to concentrate, causing your coffee to have a much different flavor after being reheated. 

How Can You Reheat Coffee Without Making It Bitter?

The answer is: gradually. Microwaving coffee at high power or setting it on the stove to boil will make a cup of coffee unpalatable as all of the bitter and acidic elements present in the beans are allowed a second chance to steep and take over your cup. Instead, try heating your coffee slowly and at a low heat to reach your desired temperature. 

Conclusion:

The bitter components in coffee are heat-activated, so reheating coffee gives those components a second chance to take over your brew. You can reheat coffee in the microwave or on the stovetop so long as you exercise patience and do so slowly and over low heat. Try this method next time your coffee falls to room temperature (or worse– gets cold!) and taste the difference.