Fermentation: Fermentation starts immediately after the yeast is put into the mixture. The chemical changes that occur continue until the yeast is killed by the heat of the oven. This is when the internal temperature reaches about 140 º F. The fermentation period is considered to end when the dough goes to the divider to be divided into individual loaf pieces (loaves).
Leavening the dough is one of the essential things that take place during fermentation. Carbon dioxide gas is produced and held by the gluten network. This causes the whole dough mass to expand which helps to condition the gluten as was mentioned previously.
Punching the dough: It is a process of punching down the dough, through the center from one end to the other at proper time. The dough then is held with both hands, grasping on one side of the dough and pulling on top. The operation is repeated, folding the opposite side of the dough. Punching equalizes the temperature of the dough, the gluten has been relaxed after its constant tension during the period of expansion. This helps to strengthen and further develop the gluten.
Fermentation time after the punch: Time after punch can be determined accurately by using fermentation ratios.
Fermentation of the sponge: Fermentation time for sponges vary from 4 to 6 hours depending upon the strength of the proteins of the flour, temperature of the sponge, and the amount of yeast used.
Dividing and scaling consists of cutting the dough into loaf size pieces and weighing the pieces to insure uniformity.
Rounding is the process of rounding the scaled pieces of dough into a round ball with smooth unbroken skin over its entire surface. The unbroken skin will retain the gas generated within the dough piece during the intermediate proofing period.
Intermediate proofing is the process of giving the rounded dough pieces a short rest period of about 12 to 15 minutes to recover from the effects of the dividing and rounding machine. The rest period allows the dough to relax after undergoing a great deal of punishment while being forced under a lot of pressure while being extruded from the divider pockets. Without the rest period the dough would be tight and rubbery and would not go through the molder sheeting rollers without tearing. The intermediate proofing machine has small pockets or baskets covered with canvas traveling within an enclosed draft free area.
Moulding: Upon completion of the intermediate proofing period, the dough pieces are molded into the shape desired.
Pan proofing is the process of rolling the panned and racked molded dough pieces quickly into the dough proofing cabinet which is well insulated and maintained at a temperature of 95 to 98 º F and a relative humidity of 85 per cent.
Baking the bread: At the end of the pan proofing, the loaves are loaded into the oven for baking. Oven temperatures vary from about 425 to 450 ºF. During the first minutes of the baking process the carbon dioxide gas within the dough expands. This expansion causes rapid rise of the dough known as oven spring. Fermentation is more vigorous and more rapid at this stage than at any previous stage. When the inside temperature of the loaf reaches 140 º F the yeast is killed and fermentation ceases. Alcohol produced during fermentation evaporates in the form of vapor. After the oven spring the pliability of the dough gradually lessons and the dough sets and slowly changes to bread. Some moisture evaporates, the starch gets gelatinized, and the gluten and other proteins are coagulated. After the loaf sets, the intense heat dries out the part exposed to the air and causes a crust to form. The golden brown color of the crust is the result of chemical changes in the starch, sugar and milk known as a browning reaction (Maillard reaction) also known as caramelization.
Within the loaf, the crumb near the crust is subjected to a temperature as high as 300 º F. The temperature gradually decreases towards the center of the loaf at which point it reaches about 212 ºF. At this temperature the gluten becomes stiff enough to give the loaf permanent form and retain its structure. When the baking process is complete, the loaves are allowed to cool for about 1 hour at which point the internal temperature of the loaf drops to about 100 ºF and is ready to be sliced and packed.
Slicing and packaging: Automatic slicing and wrapping or bagging machines and tying machines complete the major steps in bread production.
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