. Bacteria, yeasts and molds in the home. Bacteriology; Yeast fungi; Molds (Fungi). WHAT IS BREAD RAISING lOS The yeast begins to feed upon the materials in the dough and ferments the sugar, producing carbon dioxide and alcohol. Both of these materials remain for a while in the dough, the alcohol dissolving in the water, and the carbon dioxide accumulating as a gas in small bubbles. The dough is so sticky and heavy that it is not possible for these bubbles to rise up through the dough as it does in ordinary fermented liquids (Fig. 31). The gas, there- fore, simply collects as small bubbles in
. Bacteria, yeasts and molds in the home. Bacteriology; Yeast fungi; Molds (Fungi). WHAT IS BREAD RAISING lOS The yeast begins to feed upon the materials in the dough and ferments the sugar, producing carbon dioxide and alcohol. Both of these materials remain for a while in the dough, the alcohol dissolving in the water, and the carbon dioxide accumulating as a gas in small bubbles. The dough is so sticky and heavy that it is not possible for these bubbles to rise up through the dough as it does in ordinary fermented liquids (Fig. 31). The gas, there- fore, simply collects as small bubbles in the midst of the dough, causing the dough to swell.* This is the so- called raising of the bread, and the bread maker must learn from experience when it has progressed suffi- ciently. After the dough has been properly "raised" by the yeast, it may be seen to be filled with holes occupied by the gas bub- bles ^Fig. 42). Now, after the proper kneading, it is sometimes baked at once and sometimes given a second raising. The heat of baking drives off the small amount of alcohol. The heat also expands the bubbles of gas so as to enlarge the little holes in the dough, thus causing it to swell still more; but while this is being done the heat hardens the dough into the firm texture of the baked bread, and the holes previously occupied by the. Fig. 42. The same dough after yeast has grown and caused the dough to swell up by the accumu- lation of carbon Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Conn, H. W. (Herbert William), b. 1859. Boston, New York, Ginn and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbacteri, bookyear1917
