About 8ish years ago I ate gluten free, and also happened to date a pastry chef at the same time. We tried all sorts of flours, but in the end the best mix we had was given to me from my Mother’s partner Brenda, who has also struggled with gluten intolerance. We used the mix in everything (cookies, cakes, pie, etc) and the texture was quite comparable to the real deal. The one place it failed though, was in breads
Bread is one of those things that relies entirely on gluten for its texture. Yeast, once activated, eats sugar and releases gas (as previously mentioned). That gas stretches out the dough and gets caught in lots of little pockets (this is the rising stage). The next step is kneading which stretches out the flour and develops the gluten. Think of the gluten as the rebar in the loaf superstructure. The loaf rises again (when you knead the gas that developed is forced out) and then goes into the oven. While in the oven, the gluten cooks and solidifies, forming a structure that is strong enough to support the weight of the ingredients. That gas will escape over time, but the structure that is left behind remains intact.
The problem in gluten free bread is not in the development of this structure but in the maintenance. Without the elasticity and strength of the gluten, the loaf collapses from its own weight, and in doing so forces all of those gasses out. This is why bread that is baked just using rice flour has the consistency of a rubber brick.
So that is why the problem exists, and if you were to use a single flour (like rice) for focaccia you would end up with a very flat and dense loaf.
I had lots of success with the aforementioned flour mix. I can see if Brenda has it recorded anywhere (I don’t think I have it written down, stupidly enough) and would happily share if I can put my hands on it. As I recall it uses a number of different flours: rice flour, brown rice flour, potato starch, a couple of others I can’t recall, and called for Xantham OR Guar gum. I know that one of these was prohibitively expensive while the other was quite cheap. Each batch of flour didn’t require a large quantity of the gum which also helped cost.
All of this being said, there are way more GF products on the market now that simply didn’t exist back when I was eating a GF diet. Yep, that’s just how awesome I am, sensitive before it was even cool. Luckily I have been able to add it back in to my diet and with moderation I am fine. There were a couple of GF flour blends I could buy back then, but they weren’t as good as this fabled recipe that I had. I think there has been way more thought and energy put into this dietary restriction over the past ten years that there may be a blend that does the trick. I would recommend checking out blogs or books though to see what they use for a substitute.
I’m not entirely sure how helpful that was… I’ll let you know if I can find the recipe though!!