Over the years, I've seen numerous shared social media posts and have received emails about the dangers of water exploding in microwave ovens, but had never paid much attention to them, filing them away subconsciously as being urban legends.

Superheated water, however, is NOT a myth, and CAN happen in your appliance, too.

A few weeks ago, I was reheating about 16oz of coffee in the microwave, and it did just that, exploding inside the oven with a very loud bang, popping the door open and blowing extremely hot coffee all over the kitchen counter. Thankfully, it was not on a member of the family.

Had someone been standing in front of the microwave, however, it could have resulted in a serious burn, or at least would have required an additional load of laundry that day.

The coffee I was reheating had been brewed with reverse osmosis (RO) water, and that was a contributing factor to my incident.

Here are a few quick points to remember and prevent a nasty surprise or burn:

  • Use caution when heating or re-heating RO or distilled water or coffee that was brewed with either of those types of water.
  • Even though the water does not appear to be boiling (bubbles rising rapidly to the surface), it can easily be well beyond 210 degrees (i.e. superheated), and when disturbed by movement or objects being placed in the water (a spoon, sugar, instant coffee, etc.), it can explode very violently.
  • When heating water in the microwave, place a wooden spoon or even a toothpick in the water during the heating.

Here's a good article explaining the science behind superheated water.

The Chad Hasty Show airs weekday mornings live, from 8:30 AM to 11:00 AM on News/Talk 95.1 FM and 790 AM KFYO, online at KFYO.com, and on the free RadioPup app. Follow Chad on Twitter via @ChadHastyRadio & KFYO Radio at @KFYO!