Bread covered with linen proofing cloth in the the Drawer 06 – 1984 PDF. It refers to a specific rest period within the more generalized process known as fermentation. Fermentation rest periods are not always explicitly named, and can appear in recipes as « Allow dough 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 or dissolving 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 it first dissolves then begins to grow, a layer of foam is developed by the action of the yeast, a sign of primary fermentation and live yeast. 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. Length of rest periods, including proofing, can be determined by time at specific temperatures or by characteristics.
Often the « poke method » is used to determine if a dough has risen long enough. A bread that is properly proofed will balance gas production with the ability of the bread’s gluten structure to contain it, and will exhibit good oven spring when baked. A bread that is under- or overproofed will have less oven spring and be more dense. An overproofed bread may even collapse in the oven as the volume of gas produced by the yeast can no longer be contained by the gluten structure.