WEBVTT - How does popcorn work? 0:00:00.520 --> 0:00:03.600 Welcome to brain Stuff from how stuff works dot com 0:00:03.600 --> 0:00:17.040 where smart happens Hi Marshall Brain. Today's topic popcorn, the 0:00:17.160 --> 0:00:19.880 question what the heck is going on when you turn 0:00:19.960 --> 0:00:23.680 a hard corn kernel into a white, fluffy snack. It 0:00:23.680 --> 0:00:26.000 turns out that lots of grains will puff like that 0:00:26.079 --> 0:00:29.440 if you help them. People eat puffed rice, puffed wheat, 0:00:29.440 --> 0:00:32.199 and puff corn for breakfast all the time. If you 0:00:32.320 --> 0:00:35.760 soften a kernel with steam, pressurize it, and then rapidly 0:00:35.840 --> 0:00:39.960 release the pressure, most grains will puff. Popcorn is cool 0:00:40.040 --> 0:00:42.880 because it does it all by itself. The outer shell 0:00:42.960 --> 0:00:45.919 of the kernel is important. It has to be sealed. 0:00:46.280 --> 0:00:49.080 If you puncture a kernel with a pin, it won't pop. 0:00:49.600 --> 0:00:53.400 Moisture is also important. If a popcorn kernel is too dry, 0:00:53.479 --> 0:00:56.520 it won't pop either. When you heat a popcorn kernel, 0:00:56.560 --> 0:00:59.600 the moisture inside creates so much pressure that the outer 0:00:59.680 --> 0:01:03.720 shell burst like a balloon. The starch inside pots during 0:01:03.760 --> 0:01:08.520 the explosion, and you have an instant snack. Be sure 0:01:08.560 --> 0:01:11.440 to check out our new video podcast, Stuff from the Future. 0:01:11.800 --> 0:01:14.120 Join how Stuff Work staff as we explore the most 0:01:14.120 --> 0:01:19.200 promising and perplexing possibilities of tomorrow. The hou Stuff Works 0:01:19.240 --> 0:01:22.480 iPhone app has arrived. Download it today on iTunes,