When I read columns and threads on the BTD web sites, kamut and spelt seem to be the most popular flours. That is probably because they are the most like wheat in flavor and texture. I keep both kamut and spelt on hand, and use them often. Both are neutral for Os and As.

There are no beneficial flours for Os, but there are several flours beneficial for As. Because I cook for two type As, I have been trying to increase my use of flours that are beneficial for them and neutral for me.

Buckwheat flour has a very distinctive taste. Buckwheat pancakes are good. Buckwheat biscuits are very good. But I don't substitute buckwheat flour where it would overpower the other flavors in a recipe - strawberry bread or carrot cake for example.

Rice flour has a gritty texture. That's not necessarily bad, but it means that I don't use rice flour in a cake recipe where a smooth texture is important. I have a muffin recipe that uses all rice flour, and the texture is what makes it distinct. I think rice flour would be good as a breading in place of cornmeal (which I no longer use because it is O-avoid and A-neutral).

Oat flour has become one of my favorites. I bought a bag at the health food store, and thought it was a bit expensive. I liked the way it substituted in muffins and cookies. It doesn't change the flavor or texture of a recipe. However, oat flour does not rise in a yeast bread recipe. I now take ordinary whole grain rolled oats, spin them in the food processor, and make my own oat flour. I can't tell a difference in quality between my flour and the packaged flour, and mine is much less expensive.

Rye flour is also a favorite. My grocery store carries a very reasonably priced stone ground rye flour. Rye has it's own flavor, but if I mix it with kamut, spelt, or oat, the flavor is not overpowering. Of the flours beneficial for As, rye has a texture most like wheat. It also works a little better in a yeast recipe. I can make good rye rolls, but not fluffy rye sandwich bread.