Anything you bring in from outside can have bugs or eggs on them. Microwaving could be dangerous; I've seen directions to put them in a warm-200 degrees or so- oven for about an hour. Freezing also helps kill the crawlies. I put mine in a glass jar and freeze for 2-3 days. Take the jar from the freezer and let it come to room temp. before opening. I've never noticed any change in the appearance of the acorns. Hope this helps. I love acorns, too-just got some yesterday.

Boy r u in for a horrible surprise!!!!! Acorns have weevil grubs in them!!!! If your acorn has a hole in it/ 1/8" to be exact, either they have all gone, or there are more of the horrible creatures in there!!! Do more research, wash your acorns, and then bake them in your oven for 1.5 hrs, then let cool over not. Do not pick up the ones w holes, just because one came out, does not mean they are all out....Good Luck

ZAlmost forgot, back at 175 degrees for hr and a half or 2 hrs, use cookie sheet covered w foil

A good way to tell if an acorn is viable, Drop them in water. If they sink they're good. If they float , toss them out.

Baking on a foil lined sheet will work well. If you do this with pine cones, the pitch will melt and make them shiny. Your kitchen will smell a little like turpentine, though.