Pat-- I've seen water in a Pyrex measuring cup "explode" a in the microwave a few times. Happened with butter, once, too.
It usually happened when, after heating the water to boiling I let the vessel sit in the microwave for awhile, then had to reheat it. Luckily, just opening the door of the microwave was enough to jostle the water, sending most of it flying in all directions. Quite a thing to witness, but was glad my hand wasn't in the way!
It usually happened when, after heating the water to boiling I let the vessel sit in the microwave for awhile, then had to reheat it. Luckily, just opening the door of the microwave was enough to jostle the water, sending most of it flying in all directions. Quite a thing to witness, but was glad my hand wasn't in the way!