Mixing

• All breads undergo a mixing process where the base ingredients are combined to produce dough. Depending on the recipe, this can be a simple matter of combining all ingredients at once or it may require creating a simple dough or batter, called a sponge, to activate the yeast and then adding other ingredients such as more flour and salt. The resulting dough may be very firm and easy to manipulate, or contain so much water it is nearly a batter. Very liquid dough produces larger, more irregular holes in the bread, and is popular for artisan breads.
  
  

Kneading

• Kneading bread dough encourages it to develop gluten, the protein that allows it to hold carbon dioxide and rise properly. Bread can be kneaded by hand on a floured board or counter, or by machine using a dough hook. Industrial bread makers use very large, specialized machines to knead their bread dough. Longer kneading times tend to increase the bread's gluten content, making it chewier. Some recipes call for reduced kneading, which develops gluten by allowing the dough to sit for long periods of time.
  
  

Rising

• As yeast microorganisms consume the sugar in the bread dough, they produce carbon dioxide gas as a waste product. This gas becomes trapped inside the dough, causing it to rise. More gas production results in a lighter, fluffier product. Most bread recipes instruct the baker to let the bread dough rise to twice its original size, then "punch it down" or express the gas, exposing more dough surface for the yeast to act on. Bread may be allowed to rise only once, or punched down after the first rise and allowed to rise up to 3 times. Over-rising bread can allow the gases to escape and result in a sour, beery taste.
  
  

Baking

• Once the bread has risen, bakers may form it into a loaf shape directly on the baking surface or place it in a pan; then the bread is put into a preheated oven. The heat of the oven causes the yeast to breed rapidly, releasing large amounts of gas at once in a phenomenon called "oven spring." According to The Bread Baker's Apprentice, bakers often score their loaves with a knife before baking to prevent the gas produced during oven spring from bursting the side of the loaf. The scored loaf releases the gas in a more controlled fashion, producing a more attractive loaf. Eventually, the heat in the bread kills the yeast and the dough cooks all the way through, resulting in a finished loaf of bread.