The final proof is a continuation of yeast fermentation, which allows the molded dough piece to relax and expand. A dough piece that has gone through the sheeting and molding process is degassed and lacks volume.
Final proofing produces an aerated dough with optimum shape and volume when baked.1 Proofing happens in a controlled atmosphere with warm and humid conditions. Proofing temperature is generally higher than fermentation temperature, at around 32–54℃ (90–130℉).1
Three basic factors are important in the final proof:
Temperature – A range of 35–37°C (95–100°F) is recommended.1 Temperature and time factors work closely together.
Humidity – relative humidity (rh) of 85–95%.1 If humidity is too high, moisture condensation could form on the dough, resulting in a tough crust and creation of surface blisters in the finished bread. If the humidity is too low, a dry skin will form on the dough, restricting expansion and causing crust discoloration.1
Time – Proofing time should be 60–65 minutes. Overproofing results in loaves with pale crust color, coarse grain, poor texture, and a flavor with acid overtones. Underproofing yields small loaf volume, shell tops, inadequate flow, and bursting at the sides.1
During final proofing, starch is converted into sugars via enzyme action.2 The sugars feed the yeast, and the yeast utilizes the carbohydrates in the absence of oxygen to produce carbon dioxide and alcohol. The carbon dioxide is retained in the cells formed in the protein matrix, causing the cells to grow and the dough to expand.
Commercial bakeries have specialized enclosures for the final proof. These enclosures are well insulated and able to maintain interior temperature and humidity. Movement of loaded racks into and out of the proof box can be automated or manual.1 Some systems are fully automated, loading molded dough through an opening in the proof box on a conveyer system. Proofers may have conveyors in a straight line or arranged in spirals for a continuous proof-and-bake system.1
Importance of the final proof
Yeasted doughs need to undergo a final proof after shaping to regain volume and extensibility before being baked. During final proofing, acids are formed through yeast activity and contribute to flavor development. Adequate proof time is needed; otherwise, the dough pieces are unable to relax sufficiently, which can result in poor volume and a dense texture.
Final proofing time varies based on different types of doughs.
For short mix doughs, final proofing time is short, up to 1 hour.
For improved and intensive mix doughs, final proofing time takes between 1 and 2 hours.
For bread leavened only by a sourdough starter, proofing times are even longer.
Proofing time and temperature are determined by flour strength, dough formulation, the degree of fermentation, treatment received by the dough during mixing, and type of product.1
Measurement of the height of the loaf is often used to determine when the dough is sufficiently proofed. To achieve its final volume, the dough expands by a factor of three or four during proofing.2 Another way to determine when the final proof is complete is to test the dough for spring.3 Gently press the dough, and if it springs back it is ready to be baked.