The old fashioned way -- a pot on the stove.
Here is a giant Reddit thread with lots of good information:
Put oil of choice in a pot on medium high on the stove. Drop in three kernels and cover. When the kernels pop, add the rest of the kernels and cover again. Shake the pot every so often. They should start popping soon. When the pops slow to every 3-5 seconds, remove from heat and pour into bowl. Toss with a little salt and black pepper.And here is a more precise method:
Voila!
Deep sauce pan, oil with high smoke point, a splash, 4 kernels of fresh popcorn. Cover. Medium high heat. Wait for the 4 pops. turn off heat... add the popcorn. cover. let that heat soak in. for 1 minute (use a timer) [that was the magic bit]. Turn heat back up to high medium after the timer goes off. When popping slows kill the heat. Move off the burner.And again:Try to always do the same amount of popcorn to help learn what the slowing sounds like. Pour the popcorn into a bowl. If you want melted butter, put couple of table spoons of water in the pan to sizzle and eat some of that heat. Then add butter and swoosh it around to melt. Put half the popcorn back in and swirl to coat and then pour that in to the bowl again. Repeat. Take the bowl of buttered popcorn and add whatever else shaking to distribute. Do this a few times in a row to refine your version. Jot your improvements down. BOOM. You are a chef!
EDIT: somebody elsewhere in this thread suggested that for crunchier popcorn one should use a venting lid, for example a grease spatter screen. This vents steam but keeps the popcorn in. Brilliant, I just did it and can confirm... that is a winning addition to the technique and delivers significantly crunchier popcorn.
Put your coconut oil and salt on the heat along with a few kernels and wait for the test kernels to pop
Remove from the heat and put in the kernels. Put on the lid at leave it off the heat for about 30 seconds.
Put in on the heat for about 10 seconds then give it a good shake for 10 seconds. Keep repeating this until you hear the kernels sizzling in the heat.
As soon as it starts popping keep in on the heat and give it a very quick, hard shake every few seconds
The popping will be violent and only last about 20-30 seconds. It should also stop very quickly. As soon as it slows down to a few pops per second remove from the pot into the serving bowl. If you have something like an air popper, you can keep the popped kernels away from the heat after they pop. This keeps them from burning, allowing you to pop all of the kernels.
Tom's Culinary Resources / tom@mmto.org