Popcorn will work i can buy 50lb for 10-11 at sams club. You could also use whole or cracked corn from a feed store i can buy that for about 6 per 50. deer corn may not be a good choice as i have read it can contain higher nitrate content than corn meant for human consumption. you could also use home grown field or dent. I have never tried drying sweet corn but see no reason you couldnt use that also. I also use a corona hand mill. to boost the protien of your breads you can grind a tablespoon or so of soybean or any dry bean as well. also try using butermilk or eggs in your bread sometime for intresting textures. a bread dough also makes a wonderful homemade pizza roll it or press it out put a can of tomato sauce and a can of tomato paste together add italian spices for pizza sauce then pile on toppings some cheese bake hot 400 or more for a bout 10-15 minutes tell it is golden and better than pizza rut and only cost 2-3 dollars . i dust the dough and toppings with cornmeal. some more variations to try with bread are soak some whole wheat a day to soften and add them whole for wheat berry bread screen the whole wheat and toast the germ in an oven untill browned at low to med temp then add it oats can also be toasted toasting gives a nutty taste.