Here's a method that works well for me.
First, peel back the husks on the ears of corn and hang them until they are dry. I hang them from the rafters in the garage as it stays nice and warm there.
After the corn is dry, I remove it from the cob, being careful not to damage the whole kernels, and place it on a tray and let it dry a little more. At this point you have "dried corn".
You can stop now and save the corn until you are on a trip and parch it then or parch the corn ahead of time at home.
To "parch" the corn, put a little oil (optional and very little) in a large skillet and cover the bottom with a single layer of corn and roast until the kernels swell up and take on a slight brown, toasted color. Shake them around so it doesn't burn on one side.
That's it! You now have parched corn. You can eat it as is or throw it in soup or powder it to thicken soup or stew.