Is It Safe to Keep Reheating Your Cup of Coffee?

If you take three trips to the microwave every morning, this info is for you.  

Some mornings get so busy that finishing your morning coffee plummets to the bottom of your to-do list. By the time you remember those last few sips waiting in your mug, the inevitable has happened and your coffee is ice-cold.

A cold cup of coffee just isn't the same, and most of us would zap it in the microwave without a second thought. This never-ending cycle of reheating your forgotten coffee might raise a question, though. Is it safe to keep reheating your cup of coffee?

Is It Safe to Drink Reheated Coffee?

If you've noticed that your reheated cup of coffee tastes more bitter than when it was freshly brewed, you're not wrong! Coffee has natural acids that create its bitter flavor—chlorogenic acid, quinic acid and caffeic acid—and they come to life when you brew coffee. Unfortunately, when you stick your cup of coffee in the microwave, you're doing more than reheating it—you're essentially restarting the brewing process, which can release more of those bitter compounds. So, the more you heat up coffee, the more bitterness-causing acids can be produced. While reheating your coffee is safe, the resulting heated-up cup of joe may just taste a little different than you expect or desire.

an illustration of a coffee mug in a microwave
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How to Keep Your Coffee Hot All Morning

The answer to this age-old mystery is simple! Invest in a high-quality thermal mug with a lid and you'll have hot coffee for hours, extending your brew's life and eliminating the need to reheat it. Ceramic mugs and paper and styrofoam cups aren't insulated enough to keep your coffee hot for extended periods.

Bottom Line

Reheating the last few sips of your morning coffee in the microwave or on the stovetop won't cause any harm other than a bitter cup of joe. Just be sure to reheat it in a a heat-safe container. It is safe to reheat your coffee, as long as you don't mind the increased bitterness that may result.

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