1. Over-proofing. (letting the sponge or dough rise too many times)
2. Letting the dough rise at too hot of a temperature, eg. over 100 degrees. 85 degrees is the optimal ambient temp.
3. Using too much yeast per loaf. This can vary with yeast, try cutting your yeast in half.
Baking yeast makes food rise and gives it a fluffy taste and feel to your food.
Sour yeast!
the yeast
All bread has yeast in it. If your bread tastes funny after being in the freezer, then it's probably just because of the bread being old.
Yeast.
No, the oil in bread dough does not cause the yeast to rise faster. Oil improves the taste and texture of the bread.
It produces gases and causes the bread to rise.
Yeast is only used in bread products. It causes the fermentation process, which causes the breads to rise.
No, yeast bread does not cause cancer. However, some individuals have a rare disease that causes them to be unable to digest the wheat that yeast breads are made from.
It is used to make the bread inflate, therefore, it will taste better than a flat piece of bread =)
Pan de sal is a kind of bread, meaning that the yeast causes it to rise like it causes any bread to rise. Namely, yeast causes fermentation, and in breads, this interaction with the monosaccharides found in the dough creates carbon dioxide bubbles that cause the bread to rise.
Bread dough will become what is called "blown" dough. It will "blow up". Because of the gas bubbles produced by the yeast, it will keep growing until it has no structural integrity. It won't explode but may rupture and then will start turning into a puddle of goo. It also produces less than desirable looking bread and developes a bitter taste.