What substance, which makes bread rise, is also involved in alcoholic fermentation?

What substance, which makes bread rise, is also involved in alcoholic fermentation?

• A. Sugar
• B. Bacteria
• C. Yeast
• D. Salt

Answer: (C)

Yeast is the agent that makes bread rise. It’s a living organism that carries out alcoholic fermentation, turning sugars into carbon dioxide and alcohol. The carbon dioxide formed gets trapped in the dough’s gluten network, forming bubbles that lift and lightens the loaf as it bakes. In alcoholic fermentation, the same process produces ethanol and CO2, but in bread the important outcome is the gas that leavens the dough. Sugar serves as fuel for yeast, not the leavening itself, while salt can slow or inhibit yeast activity, and bacteria are involved in other kinds of fermentation but not the usual bread rise.