We just had a small "event" in the kitchen. I'm in the next room and hear this small "whump" and an exclamation from the kitchen. I run in and find water all over the floor, ceiling, and my wife. My wife had heated a glass coffee cup of water in the microwave for tea, took it out, then dipped a tea bag in. She's ok, just a little burn on her wrist. There's only about 1/2 oz of water left in the cup. Thank goodness she had put the cup down before putting the tea in.
We've both heated water this way many times before, usually to boiling or just below, and the worst that's happened in the past is the tea bag fizzes.
Gunpower tea? 🙂
"Tea Party": subversive packaging
Tyler-
As a Canuckian, I could not help myself ! 😀
TNAI
"Tea Party": subversive packaging
I have had this happen to me before, I was using a Pyrex measuring cup. Luckily, a toothpick in the bottom of the vessel is all that is required to ensure that it doesn't happen:
http://www.animations.physics.unsw.edu.au/jw/superheating.htm
"Tea Party": subversive packaging
My Dad's story is when he was a kid you could purchase kits to make Disney characters out of lead you melt on the stove (no really this is true according to him). This is the 1930s. My Grandfather's rule was that Dad and his brother (my Uncle) were never to do this by themselves. Naturally one time they did it when no one else was home. They melted the lead on the stove top and one of them threw a cold ingot in there and BLURP!!! lead went onto the ceiling (luckily neither of them got hurt by flying molten lead).
When my Dad was alive and we asked which did it he would say his brother. So I questioned Uncle Ben about it and he said, "Oh no, your Father threw the cold lead in." They never did agree who was at fault there.
Holy crap!! That must of scared the crap outta her! It would me. :-O
Thank goodness she is OK. I have heard of instances where the actual cup explodes, sending glass sharpnel everywhere, including into human flesh. :-/
that is the main reason I am very careful about using Glass or Ceramics in a microwave. I generally use polyvinyl plastics.
Using plastic will avoid having the container explode, but you can still heat water above it's boiling point in a microwave and under the right conditions it will flash into steam almost instantly when disturbed.
My parents had a glass baking dish explode in the oven. Yes it was made for baking and it had been used before. It was also baking at normal temps.
Stephen, seems like you are the only one who knows the cause of this.
jud
There's a relatively complete description of the phenomenon in the link provided above by Dwight... er, I mean Adam3000i.
There's a related phenomenon called "supercooling". There are heat packs that take advantage of the supercooling phenomenon. They start out like plastic bags full of liquid, then when you squeeze a small piece of metal, it creates nucleating sites, causing the super-cooled liquid to suddenly "freeze", producing lots of heat.
Any liquid heated on high (or for longer than a few minutes) in a microwave should be left to sit for at least a minute before opening the door and moving or touching it.
What you have in there is literally "boiling water that is not boiling". If you notice, all boiling in water begins on the surface of the container when you are heating it in a pot or kettle. Throw some pasta into boiling water, and it will foam up and often overflow....this is the same principle, but with water actually boiling and bubbling.
Microwaves heat the water itself, rather than the container, so there is a different molecular reaction, and the bubbles often do not form.
If one quart of water is superheated by only 1 °C (i.e. if it is heated to 101 °C without boiling at normal pressure), it is in an unstable state, and it can suddenly produce about 3 quarts of steam. Adding a tea bag or a spoonful of sugar, or sometimes even just moving the cup out of the microwave will cause the unformed bubbles to rapidly (VERY rapidly) form, and blow out of the container, to the point of seeming to explode.
So re-warming a cold cup of coffee with a "Quick Minute" button is dangerous?
I did not know that ...
Sicilian Cowboy nailed it in his post below.
Oh no I do that all the time. I don't want to heat it hot enough to boil, though.
I do know you should never try to hard boil an egg in the microwave oven. It will explode.
That has to do with surface tension and the water just barely hitting boiling temperature, as based on atmospheric temperature. I used to remember the formula on how to calculate the temp based on pressure or pressure based on temp. Too many years have passed since I did that.
