Kneading Bread

Bread made with yeast is usually kneaded that is, drawn out and pressed together to create a distribution of the ingredients. Then the bread dough is set aside to “rise.” Why is some bread then kneaded a second time and sometimes even a third time before baking?

Answer

Each successive kneading of the bread dough distributes the CO₂ gas released by the action of the yeast to make a finer texture that is, smaller holes more evenly distributed throughout the bread volume. Initially, the concentration of yeast is not uniform but has some non-uniform volume distribution in the bread dough. Where there is more yeast, there will be more CO₂ gas produced by the yeast chemistry and usually bigger bubbles in the region. At the molecular level, CO₂ molecules released by the yeast will diffuse into the surrounding dough somewhat, probably not moving very far in the available time. Some of the gas bubbles may even coalesce to form bigger bubbles. Without further kneading, some places in the bread will possess many bubbles or large bubbles, and other places may have very tiny bubbles or none. We have all seen bread with a non-uniform distribution of bubbles, or even with one large bubble somewhere. A more thorough kneading would eliminate these oddities, unless they are planned.