‘Tis the season for spending time in the kitchen making those holiday feasts. So, when we were choosing a timely experiment to send in our Experiment of the Week email, we figured that Exploding Water in the Microwave was a great choice to make sure everyone had a safe and happy holiday. Our choice was affirmed when a reader took the time to let us know about the value of this experiment…
Now watch the video…
I was very interested to receive the email about water from the microwave exploding. Let me tell you my story. I make a pot of c
offee in the a.m. and then just reheat it in a mug throughout the day. I have done this for many years. Several months ago, without any thought, I went through my usual routine coffee heating, same mug, same power, same time as always. When completed, I set the mug on the counter and, as always, added a spoonful of powdered coffee creamer. The reaction was unbelievable and so fast that, initially, I could not comprehend what had happened. There was literally coffee everywhere in my kitchen and all over me. Fortunately, I was not burned. My face just felt a little warm and rosy for 24 hrs. I have included photos of the coffee “hanging” from my 8-ft kitchen ceiling. All the cupboards including those 4 ft away were covered with coffee splatters. The 10 oz mug had about 1/2 in or less of coffee left in it. Several months later, I am still finding a spot of coffee in obscure places here and there in the kitchen. So – thank you for putting out the warning. I have sent it on to many family and friends.
— Lucie from Ohio
It is really an honor when our customers let us know that what we are doing has made a difference to them. Thanks Lucie for your email and for the lesson learned!
Heating water in the microwave can actually be dangerous. A man decided to have a cup of instant coffee, so he heated a cup of water in the microwave. When the timer went off, he removed the cup from the microwave and noticed that the water had not boiled. Just then, the water literally “blew up” in his face. His whole face was blistered with first and second degree burns, which left some permanent scaring and damage to his left eye. While at the hospital, the doctor attending him stated that his is a fairly common occurrence. Water (alone) should never be heated in a microwave oven. Why?
Read the full explanation of Exploding Water in the Microwave
This phenomenon is known as superheating. It can occur anytime water is heated – especially if the cup or bowl is new. What happens is that the water heats faster than the vapor bubbles can form. If the cup is very new, then it is unlikely to have small surface scratches in it that provide a place for the bubbles to form (called nucleation sites). Without bubbles, the water cannot release the heat that has built up, the liquid does not boil and it continues to heat up past its boiling point. If the water is bumped or jarred, it’s enough of a shock to cause the bubbles to rapidly form and the result is an exploding liquid that is scalding hot. One solution is to place a wooden stir stick or something non-metallic in the water to help diffuse the energy as it’s heating in the microwave.
While sharing this story with audiences, I’ve learned that many people have had similar experiences but never understood why the water just blew up. It’s an important piece of science to share with others in hopes of preventing a potential disaster.