A recent discussion over microwave popcorn prompted me to steal this excerpt (and reformat it for blog reading) from Alton Brown's first book "I'm Just Here For The Food".

Homemade Microwave Popcorn

Software

1/3 cup popcorn
2 to 3 tablespoons melted butter
Popcorn salt to taste *
1 tablespoon Parmesan cheese, finely grated, or other "cheese sprinkle" (optional)

Hardware

Small paper bag (standard lunch size is fine)
Stapler (use exactly 2 staples, no more no less)
Microwave oven with a carousel (important for even popping)
Large mixing bowl

Application: Microwave Cooking

Pour the popcorn into a paper bag and fold the top of the bag over twice to close (each fold should be 1/2 inch deep; remember, the kernels need room to pop).
Seal the bag with 2 staples only, making sure to place the staples at leas 2 to 30 inches apart. **
Put the bag in the microwave over and cook on high power for 2 to 3 minutes, or until the pops are 5 seconds apart.
Remove the bag from the oven and open it carefully, avoiding the steam. Pour the popcorn into a bowl and drizzle it with the butter, then toss with salt and cheese, if desired.

Yield: 6 to 8 cups of popcorn

I've made this stuff six ways from Wednesday and unitl recently I always tossed the kerels in oil before placing them in the bag. But the more I learned about microwaves, the more I started to think this might be unnecessary. After all, the stuff that does the popping (water and plenty of starch) are on the inside of the kernels. The kernel itself doesn't need to brown, so why bother with the added mess? I ran a quick test batch and never looked back.

Although many home poppers advocate the use of other culinary oils in place of butter, I just can't break with this tasty tradition. However, I do like a sprinkle of cheese now and then. Oh, and if you're interested, toss a tablespoon of dark brown sugar in the bag sometime.

Why is Popcorn the Perfect Microwave Food?

Popcorn pops because its kernels contain a high amount of moisture. When heated, that moisture eventually turns to steam. Unable to contain the increased volume of the vapour, the starchy kernel blows out in all directions and freezes in a puffy configuration, which itself results from the rapid drop in ambient pressure. Since it only heats the water portion of the kernal, microwaves can pop corn without burning it. If yours does burn from time to time, blame the oil, which can get hotter than water.

* This is one time koshe salt just won't do. Popcorn salt is very fine, so it sticks readily to the poped kernels. If you can't find it in your local Mega-mart, go with (hate to say it) table salt.

** As long as you're using a microwave oven with a turntable and you don't place the bag where the staples can rub against one of the walls, nothing bad will happen. This is because staples have very little mass and they are shorter than the microwaves themselves, which means they're basically microwave "invisible". So don't be afraid to try the recipe.