Reading yesterday’s post That Mysterious Secret Ingredient, a good friend (and baker) observed that I wasn’t terribly clear about the role that non-flour substances (like corn starch and almond flour) play in doughs of various types. In particular, she felt that the term “tenderizer” sounded misleading. Since I hate to confuse simple matters, I’ll try putting it a different way.
Wheat is unique among grains in that it has gluten. And gluten, as I’ve discussed many times, is made of protein molecules which, when combined with water and agitated, bond to each other to form a stretchy, tightly woven network. This network is what holds a dough together. Without gluten you’d just have a wet wheat paste that couldn’t be kneaded, wouldn’t rise, and would bake up into a dense, dry, crumbly mass.
But elasticity in a dough isn’t always desirable, as in a tart dough, which you want a little dense and crumbly. So bakers intentionally disrupt gluten networks by introducing other substances to the mix. These can be just about anything, from bits of hard cooked egg yolk to ground nuts to corn meal, just so long as they have no gluten. The result is a dough with enough developed gluten to hold it together, yet not so much that it takes on the tough, stretchy properties of a bread dough.
That’s what I meant by “filler” or “tenderizer”. Clear enough now?