So I read on this site that you are supposed to heat an over to 200 degrees F (or another site says 300 degrees) and put the pine cones on an aluminum foil covered baking tray for approximately 30 minutes to open pine cones, kill the bugs, and let the heat melt away the sap.
I was out of aluminum foil so I put the pine cones (I have lots) in plastic zip-lock bags and stuck them in the freezer to kill off all bugs until I could go buy some aluminum foil.
After approximately three days in the freezer, I left them out in a room (at room temperature), but never opened the bag, which apparently re-opened the pine cones that closed while in the freezer.
Today I have the foil and followed the above instructions and it didn't work! (Let me explain.)
I put batch "A" in the oven on 200 degrees F for 30 minutes and nothing happened (keep in mind they were already opened, but still no sap ran out and I didn't see any bugs or anything). I decided to leave it in the oven an additional 10 or so minutes. Batch "A" was in the oven at 200 degrees then for approximately 40-45 minutes and nothing happened!
I put batch "B" in the oven at 300 degrees F for 30 minutes. The "only" difference is for batch "B" I started to smell the pine cone scent, but that is it.
Now, keeping in mind that I want to use the oven approach (rather than bleach or whatnot) and that my pine cones are all already opened. My questions is what should I do to the oven setting/time to heat the cones so that they release the sap and kill off any remaining bugs?
By Mourning_Star from IL
This answer has been rated the best for this question.
By Vicky  10/03/2012
Maybe it was a dry year and the pine cones didn't have much sap to start with - were they very 'sticky' when you picked them up? Maybe there weren't any/many bugs on/in them to start with - did you see any when you picked them up? If the cones were completely dried out when you removed them from the oven and weren't sticky with sap, I would think they'd be fine at this point for decorating! I have dried pine cones before on alum. foil in a low temp. oven and they turned out great. Blessings.