There are several possible reasons why dough might not rise: Yeast expiration: check the date of the yeast and ensure it is not expired. Improper yeast activation: Yeast needs warm liquid (not hot) and sugar to activate, if the temperature is too high or too low or the yeast is dead, the dough won't rise. Lack of moisture: Yeast needs moisture to survive and grow, so dough that's too dry will not rise. Too much salt: Excess salt can inhibit yeast growth and prevent the dough from rising. Improper kneading: Kneading dough helps develop gluten, which traps gases and makes the dough rise. If the dough isn't kneaded enough, it won't rise as it should. Over proofing: If the dough is allowed to rise too long, the yeast will exhaust itself and the dough will deflate. Room temperature: Yeast rises best at warm temperatures, if the room is too cold, the dough will rise slowly or not at all.