The Brown Bag Microwave Popcorn Trick by The Brown Bag Microwave Popcorn Trick You never have to buy microwave popcorn again! Add 1/3 cup popcorn kernels to a brown paper bag, fold the bag over twice then heat in a microwave — folded side down — for 2 minutes. THAT’S IT! Fresh popped popcorn without any fuss, ready for you to flavor as desired or eat completely bare.