Mixing and Gluten Development
Gluten is a substance made up of primarily two proteins present in wheat flour. It gives the product its structure and resilience.
Gluten is developed by first absorbing water. Then, as the dough or batter is mixed, kneaded, or folded, the gluten forms long, spring-like elastic strands. If the dough or batter is leavened, the strands capture gases in tiny pockets or cells, and we say it begins to rise. However it is also resilient and tries to shrink back and retain its shape. By allowing the dough to bench rest before make-up (shaping), the gluten has a chance to relax making it easier to manage.
There are several factors and ingredients that help in controlling gluten development.
Flour is one of them. Flour is mostly starch and knowing the protein content determines what kind of flour to use when making breads, cakes, or pastries. Strong flours come from hard wheat and have high protein content. Weak flours come from soft wheat and have lower protein content.
Flour grown in the United States has a higher protein content than flours grown in Europe. There are six main categories of wheat grown in North America. They are listed in order of highest to lowest protein content:
Durum: basically used for pastas
Hard Red Spring: used in breads that require strong bread flours
Hard White: high-protein wheat grown in smaller quantities
Hard Red Winter: moderate strength wheat grown in large quantities
Soft White: low-protein wheat used in making cakes, pastries, and crackers
Soft Red Winter: low-protein wheat used in making cake and pastry flours
Shortening is anther factor in gluten development. Solid fats or oils affect the gluten by shortening the strands. Shortening acts as a tenderizer. When a fat is introduced into a formula, the fat bonds with parts of the gluten protein and stops it from forming strong gluten strands. When fat is introduced the dough becomes more flaky and crumbly.
Mixing, kneading, and folding also affect the outcome of a final product. Pie dough is an example of this. It can either be “flaky” or “mealy” depending on how long the dough is worked. The less it is worked, the more tender and flaky it is. In essence, the longer dough is mixed, kneaded, or folded, the more gluten it develops. Bread dough is mixed for long times, while pie crusts, cookies and other similar products are mixed for shorter periods of time.
Finally, liquids also have an affect on gluten development. Because gluten proteins must absorb water to develop, the amount of water in a formula directly relates to the toughness or tenderness of a specific product. Formulas with less water produce crispier and flakier products.