For years I've been lazy and used the microwave to sterilize water for primer sugar and to rehydrate water for yeast. Never found any problems with yeast or beer doing it this way. I've always been curious if this changes anything in the water.
Ski12568 said:Add a chop stick or something similar so you do not burn yourself. Water in a glass container can get above boiling temp in a microwave and not boil, an accidental bump of the pyrex can start a vigorous boil and splash. The chop stick gives a place for the boiling/bubbling to start so you can see that its hot. This is really only true for distilled water but better safe than sorry