I recommend an oven of 200 degrees for 20 minutes and let it cool in the oven. 130 for 15 minutes is really saying that the bran needs to be at 130 for 15 minutes, not the oven. You can either leave it at 130 for a long time or just up the temp to 200 for 20 minutes or so. 2 hours is way too long in my opinion. I also think that microwaves heat too uneven and you might get some but not others.question- I need to add some wheat bran to our worm container, I read that I should heat it up in the oven 130 degrees for 15 minutes to make sure it is bug free- can we microwave the bran and if so how long?