Can You Reheat Coffee?

Getting a sudden call or in the rush of a busy routine, it is possible for your hot coffee to become a lukewarm brew. You have two choices, either to heat it again or to not heat it. It is important to know that coffee is a “one-time use” item that should not be reheated. If it gets cold while you were pre-occupied in some work, then the best thing is to prepare some more. There are reasons why reheating a coffee is not advised.

Can You Reheat Coffee?

How does coffee obtain its flavor?

Coffee obtain its flavors from the complex chemical structure. There are around one thousand different chemical compounds that are responsible for giving a distinct taste to your coffee. These chemicals depend on various factors such as the way the coffee beans got harvested and the type of soil in which the coffee plant was grown. Presence of high amounts of 3-methyl butanal, gives a strong caramel flavor to the coffee.

Harms of reheating your coffee

When your coffee cools down and comes to normal temperature, then its chemistry gets modified. Reheating further rearranges the chemical formation of the coffee. It breaks down any left aromatics. It completely damages its flavor. The acidity in coffee increases when it cools and so it tastes bitter.

Coffee that is left out for long time periods can easily expose to pathogens and other types of bacteria. This is more likely to happen when it contains milk in it. Another important food safety consideration is development of molds in the coffee. These molds can grow on your coffee. It will appear as a thin film that floats over the drink.

Reheating can destroy the bacteria present in coffee. This happens when it is boiled for a few minutes. In this case, it will damage the flavor of your coffee totally. Microwaving your coffee can destroy bacteria, but it leaves “cold spots” in it where there are chances for the bacteria to survive.

Better option is to drink the coffee in cold form. If you have a thermos, then store your coffee in it. It will keep it warmer for some more time without any changes in its chemical structure or taste. You can even start from scratch. Thus, both cooling and rewarming of coffee contribute to its bad taste.

How does temperature impact the taste of coffee?

When coffee gets cooled or heated, then the compounds present in it alters its smell and taste. The fruity smell comes from the coffee beans. Once the coffee gets reheated, this distinctive smell quickly declines.

Experts have found that the cooling make its taste on an acidic flavor profile. It happens due to oxidization of coffee when it gets exposed to air. Slow heating will reduce the occurrence of chemical reactions. Avoid reheating your coffee that has sugar or milk in it as they can add more compounds to it that will change its original taste.


Some food items do not work to reheat. Coffee is one of those foods. Keeping your health in mind, it is best to simply drink a fresh cup of coffee.