In bread baking terms, proofing or proving means to allow the bread dough to rise. The proof refers to the fermentation action of the yeast causing the dough to rise and create an airy texture. In most basic yeast bread recipes, the dough is allowed to proof twice.
Proofing refers to the specific rest period or amount of time that fermentation occurs. Fermentation is the necessary step in creating yeast bread and baked goods where the yeast is allowed to leaven via fermentation causing the dough to rise. The alcohol produced by the yeast during fermentation—along with a multitude of other reactions—is what gives great bread its characteristic flavors and aroma. Generally speaking, more fermentation means tastier bread.
These fermentation rest periods are also referred to as the time the dough is "allowed to rise," "bulk fermentation," "first rise," "second rise," "final proof," and "shaped proof."
Rising is the most dramatic physical change a dough undergoes on account of yeast activity. Technically speaking, rising is a product of a process called respiration, which happens because of the fermentation. As the yeast eats sugars, it releases carbon dioxide in the form of tiny air bubbles in the dough. As the yeast "breathes" or respires, it causes the bread to grow and rise.
The bulk fermentation, or first proof, for any dough is a crucial step in the bread-baking process. It is called bulk fermentation because you are letting the dough—the entire batch—ferment as one mass before dividing and shaping it into loaves or rolls. It is during bulk fermentation that the yeast does the majority of its work, helping your dough gain flavor as alcohol and other byproducts are produced and gain structure as carbon dioxide inflates the bread.
At comfortable room temperature, bulk fermentation will take one to two hours. As a rule, a warmer dough will rise faster than colder dough, so make sure you take stock of your prep environment.
After punching down, kneading, folding, and stretching your dough, you will portion out the dough into serving sizes or loaves. You get it ready for its final proof by putting it into its final shape.
You can place the shaped dough into baskets, bowls, or bread pans, cover with towels, and perform a shorter second rise at room temperature or in the refrigerator. During this time, the loaves should nearly double in size. Proofing loaves in the fridge, known as retarding, will slow down the final rise. This can give your loaves more flavor and make them easier to handle and score before baking.
Over Proofing and Under Proofing
Over proofing occurs when a fermenting dough has rested too long, resulting in the bubbles growing so large that they pop. Dough baked at this point would result in a bread with poor structure. Leaving the dough for longer than needed and/or a proofing environment that is too warm can cause over proofing.
Under proofing can also negatively affect the structure. Not leaving the dough to rise for long enough and/or a room that is too cool can cause under proofing. If you poke the dough and it springs back immediately it is under proofed and needs more time. Some breads are considered fully proofed if the indent left by the poke springs back slowly, while others are considered fully proofed when the indent remains and does not spring back.
Special Proofing Equipment
While no special equipment is needed to proof bread, you can use items to assist during this important step of bread making:
- Dough proofer or proofing box: This creates a warm environment with controlled humidity for ideal proofing conditions.
- Dough retarder: A refrigerator for the final proofing of dough. It controls the fermentation of yeast, which can help make a more sour and flavorful loaf of bread.
- Banneton: A basketlike container used for final proofing. It often creates a pattern on the top of the bread.
- Couche: A cloth used to wrap or cover your final proof as it performs its final rise.