This section is from the book "The American Woman's Cook Book", by Ruth Berolzheimer. Also available from Amazon: The Domestic Arts Edition of the American Woman's Cook Book.
Old Yeast - Dead yeast plants can not leaven bread. Old compressed-yeast cakes or dry yeast which has been stored away until many of the yeast plants are dead will act very slowly if at all and will not give best results.
Too Much or Too Little Kneading - Over-kneaded dough becomes sticky and will not rise well in the oven. Under-kneaded dough makes streaked bread, poor in texture, which sometimes contains lumps that might have been worked out in the kneading.
Too Much Flour - Too stiff a dough rises very slowly and therefore often is not allowed to rise sufficiently. This is a green dough and produces a loaf with poor flavor.
Over-Rising - Too long rising gives a very porous loaf with little flavor, a pale crust and a porous crumb with broken, irregular cells. This bread crumbles badly. If the rising continues too long, the bread is sour.
Under-Rising - This gives a bread of dark crust which has blisters just under the crust. The loaf is small and flat. It browns easily in the oven. Such dough is said to be green.
Too Cool an Oven - Bread will continue to rise too long if the oven temperature is too low. The result is bread that is very porous in the center and upper part of the loaf.
Too Hot an Oven - The dough crusts over immediately and can not continue to rise the first ten or fifteen minutes it is in the oven, or the crust may break as it is forced unusually on one side more than the other. The crust becomes very brown while the center is underdone.
Rope in Bread - This appears during hot, damp weather.
It is due to the presence of a bacillus and the ropy, stringy-quality does not develop immediately after the bread is baked. Rope gives bread a very disagreeable odor and makes it unfit for use.
If rope develops all utensils used in making bread and containers in which bread is stored should be sterilized with boiling water. Vinegar equal to two per cent, of the amount of flour used should be added to all bread made until the supply of flour is exhausted. This is approximately one-half ounce (one tablespoon) of vinegar to one and one-half pounds of flour.
Mold - Bread wrapped while hot molds quickly. Containers used for storing bread should be washed and aired frequently, and immediately if mold is found.