Why does spraying popcorn with oil (Pam) make it pop better in a paper bag?

I'm still experimenting with popcorn microwaved in a paper bag. I tried putting the kernels in a dish and giving them a quick shot of Pam. Then I poured the lightly coated kernels into the bag.  They popped much better although it took slightly longer to start popping.  I don't understand what's going on.  Any explanations?

kelseymh7 years ago
Pam, or olive oil, or even melted butter will do the trick. Burf got it right -- the oil is very wetting (it spreads out) and has a high heat conductivity. Put the two together, and you get good uniform heating of the kernels from the outside as well as from the inside (the microwaves heat the water directly).
Burf7 years ago
Because the oil gets hotter and heats the kernels faster and more evenly than without it.
kelseymh Burf7 years ago