Bread covered with linen proofing cloth in the background. Fermentation rest periods are not always explicitly named, and can appear in recipes as “Allow best proofing basket to rise. When they are named, terms include “bulk fermentation”, “first rise”, “second rise”, “final proof” and “shaped proof”.
The process of making yeast-leavened bread involves a series of alternating work and rest periods. Work periods occur when the dough is manipulated by the baker. Some work periods are called mixing, kneading, and folding, as well as division, shaping, and panning. Some breads begin mixing with an autolyse.
This refers to a period of rest after the initial mixing of flour and water, a rest period that occurs sequentially before the addition of yeast, salt and other ingredients. Proofing the yeast’ is a hydration process that occurs when dry yeast is mixed with warm water and allowed to rest for a short time. Yeast viability can be tested by mixing yeast in warm water and sugar, and following a short rest period during which the cells first accommodate to the environment and then begin to grow, a layer of foam is developed by the action of the yeast, a sign of primary fermentation and live yeast. While this sugar may be sucrose or table sugar, instead it may be glucose or maltose. Fermentation typically begins when viable baker’s yeast or a starter culture is added to flour and water.
Enzymes in the flour and yeast create sugars, which are consumed by the yeast, which in turn produce carbon dioxide and alcohol. Different bread varieties will have different process requirements. These are generally classified as either straight or sponge dough processes. Straight doughs will require only a single mixing period. Overproofing occurs when a fermenting dough has rested too long. Its bubbles have grown so large that they have popped and tunneled, and dough baked at this point would result in a bread with poor structure.