corn meal versus corn
I have had bugs and moths in corn meal. Why not store corn and then grind it as needed? I read recently that most of the yellow field or dent corn is GMO, but popcorn, white and blue corns are not GMO. Blue corn has a higher protein content than yellow corn.
There are many options for flour besides wheat and other grains with gluten. As with anything, it takes time, experience and experimenting to find out what you can do with them. If you haven't done any cooking with them, start. It seems that combining a variety of flours adds to the flavor and texture. The one challenge in cooking with gluten free flours is to get the right texture.
Sorghum flour is a popular one. It is made with a small grain, sometimes called milo. It is mostly raised in the northern plains states--South Dakota and Nebraska for sure. Milo could be stored for future grinding.
Garbanzo beans can be ground into flour.
Rice is a common gluten free flour. All types of rice are used.
My daughter, a celiac, has used almond flour with great success.
If I was a prepper with gluten challenges, I would have a grain grinder dedicated to gluten free grains. I am not gluten free, just my daughter. We often question whether something has gluten or not. Since she has been living gf for a few years, gluten exposure can make her very sick with digestion issues keeping her close to the bathroom, vomiting and migraines. It is a serious problem for her. I have worked on getting gf preps together, but I do find it much more challenging than buying a few hundred pounds of wheat.