Difference Between Quick Bread and Yeast Leavened Bread
Bread varies according to the richness of the formula and the physical make-up of the dough pieces. White, open-top pan bread is the most popular in the United States and accounts for about 80% of all bread produced in the country. The remaining 20% consists of hearth-type breads, rolls, rye bread, and other variety loaves in which formulas are changed to make products that satisfy specific customer demand and preference.
Breads are further classified according to the leavening agent employed:
Quick breads are leavened (raised) by a chemical leavening agent, such as baking powder. Because quick breads do not require a fermentation period, they can be made up into the desired shape and size and immediately placed in a pan (panned) and baked. Quick breads are more dense than yeast-leavened products, and have a coarser grain, lower volume, and a crumbly texture.
Yeast-leavened breads are leavened by carbon dioxide gas resulting from yeast fermentation. The dough is further modified during the fermentation period and becomes more palatable than chemically leavened breads. Yeast leavened breads may have much larger volume, closer grain, thinner cell walls, and a more silky texture than quick breads.
Staling causes great losses and is the industry’s most severe problem. Staling begins as soon as the product leaves the oven and occurs most rapidly when the product is fresh. The most rapid staling and firming take place between the temperatures of 90° and 35° F (32° and 1.7° C). Below 35° F, staling slows down. If the temperature is lowered to 0° F (−18° C), staling is very slow, and bread will keep for months at this temperature without apparent staling. Little is known about the changes in aroma and flavor that accompany staling. Other aspects of staling are caused by changes in moisture and starch. Loss of moisture increases firmness, crumbliness, and harsh texture. Loss of moisture can be avoided by wrapping the product in film.