Wheat flour lacks the deep flavor and color of rye or buckwheat and the sweetness of oat or corn flour, but it remains the best choice for bread baking because of its ability to produce gluten. That's why it's used for breads such as ciabatta, a modern Italian bread that derives its crisp crust and open, airy texture from strong wheat gluten. Corn flour is more flavorful and has an appealingly rich color, but has no gluten at all.
A Quick Gluten Primer
Wheat flour contains a pair of proteins called glutenin and gliadin, which contribute to the grain's nutritive value. When the flour is moistened, those two proteins bond together to form long, stretchy strands called gluten. Gluten is crucial to yeast-raised breads because it makes the dough elastic enough to trap the bubbles of carbon dioxide produced by yeast as it digests the dough's sugars. Without that stretchiness, the dough would not rise.
The Corn Problem
When it's baked, ciabatta dough puffs up dramatically and creates a relatively flat loaf with a large, open network of air holes inside. This requires a high level of gluten in the flour, which argues against the use of corn. Corn is a staple of gluten-free baking, which is wonderful if you suffer from celiac disease but not if you're baking bread. You can include corn flour in your ciabatta for its flavor and color, but only on a small scale.
Adding Corn, Adding Gluten
You can usually substitute corn flour for up to 25 percent of the wheat flour in your ciabatta, without affecting it too dramatically. For the best possible result, use high-gluten bread flour or add a small quantity of concentrated gluten from your local bulk foods store. Whether you include some corn in your dough or not, it's handled differently from ordinary sandwich bread. Most breads are kneaded for an extended period, which forces the protein molecules together and forms gluten rapidly. It's a useful technique, but it's only suitable for stiff doughs.
Ciabatta bread uses a different approach. The dough is very wet, or "slack," compared to other breads. It can't be kneaded effectively, so the gluten strands must form on their own as the dough rests. Instead, the dough is periodically stretched to stimulate gluten development. The risen dough is turned out onto the counter, then lifted and stretched from beneath to form a rectangle. That rectangle is folded in thirds, like a letter, to make the signature "slipper" shape that gives the bread its name.
If your goal is a completely gluten-free ciabatta loaf, that's a bit more complicated. You can use corn flour as part of a gluten-free mixture, but you'll need xanthan gum or a similar additive to replace the elasticity of the gluten and help give the bread some rise. Supplementing the yeast with a bit of baking powder, and baking at a temperature of 400 degrees Fahrenheit or higher, can also help the bread puff and resemble ciabatta more closely.
- On Food and Cooking: The Science and Lore of the Kitchen; Harold McGee
- The Bread Baker's Apprentice: Mastering the Art of Extraordinary Bread; Peter Reinhart
- Photo Credit Hemera Technologies/AbleStock.com/Getty Images