Will Mold Grow Faster on Wheat or on Italian Bread?

Molds on Foods

• Molds are fungi made of multicelled organisms that have spores that transport the fungi through the air. Molds on food can have roots that reach deep into the food, with spores visible to the naked eye, such as the white or green color of mold you see on breads. The molds you see on breads appear to have a fuzzy appearance, and given enough time they can spread out to cover a whole slice or loaf.

Life Cycle of Bread Mold

• The life cycle of bread mold begins with the airborne spores. Heat and moisture assist the mold in sprouting hairlike objects called hyphae, which appear to be fuzzy spots that spread out over the bread. Mold spores are virtually everywhere and can affect any food item, such as breads. Commercially prepared bread contains preservatives to inhibit mold growth. The bread contains edible acids like the acetic acid in vinegar to control the spread of mold. Additionally, salt and sugar decrease the chances of mold production in breads, regardless of whether they are wheat or white breads. When wheat or Italian breads do not contain these preservatives, the high water activity alone encourages the growth of mold at the same rate in both.

Contributing Factors

• The water activity in bread is a contributing factor to the susceptibility to mold. According to the U.S. Food and Drug Administration, most foods have a water activity of 0.95, which is enough moisture to produce mold. Perishable foods such as breads have a water activity of 0.95. Additionally, the pH, or acidity, in bread determines how quickly mold forms. Breads -- wheat or Italian -- generally have a pH level of 5.3 to 5.8, which helps to preserve them for a longer shelf life.

Slowing Mold Growth

• Heat and humidity contribute to mold production in breads. Storing tightly wrapped bread in the refrigerator and toasting the bread, which lessens the moisture content, slow the growth of mold. The U.S. Department of Agriculture suggests discarding breads with mold in them, as the mold is likely to be throughout the dough.