Proofing
Resting a yeast dough so that it fills with gas and rises before baking.
Also: proving, rising
During proofing, yeast in the dough feeds on sugars and gives off carbon dioxide. The stretchy gluten network traps the gas, and the dough swells. Most breads rise twice: once after mixing and again after shaping. Warmth speeds the process and cold slows it, so many bakers proof dough overnight in a refrigerator for better flavour. Underproofed bread is dense. Overproofed dough collapses in the oven. The word is also used for testing that yeast is alive.