There are several reasons dough may not rise:
Yeast may not be fresh.
- Yeast has an expiration date and after that date will not be as effective.
- Yeast should be stored in a cool, dry place.
- Yeast may have been dissolved in too hot of water or the liquid ingredients in the recipe may be too hot, causing yeast to die.
- Ingredients may have been too cold causing some of the yeast to die.
- Dough may not have been kneaded adequately.
- Kneading "exercises" the gluten in the bread and gives it the elasticity to hold in the air bubbles produced by the yeast.
- It is these air bubbles that cause the dough to expand and rise.
- Insufficient time may have been allowed for dough to rise properly.
- Dough may have been placed in too hot of place for rising.
- The optimal temperature for rising dough is from 70º to 90º F.
- At higher temperatures, the yeast will begin to die.
- If specialty grains are being used in dough, the dough will not rise as much because these grains have a lower percentage of gluten to hold in the air bubbles that cause the bread to expand.
- If sourdough starter is being used, it may not be active.
- Sourdough starter must be fed at proper intervals and kept at the correct temperature to keep the yeast cultures alive and active.