Yeast Fermentation and Baking Evaporation

Steps:

• Yeast ferments sugars in dough, producing carbon dioxide for rising and ethanol as a byproduct.
• During baking, high heat causes the dough to cook and expand.
• Ethanol, with a low boiling point of 78°C, turns to vapor under oven temperatures above 100°C.
• The vapor escapes, leaving minimal alcohol in the finished bread.

Why C is correct:

• Ethanol evaporates due to its boiling point being below typical baking temperatures (around 180–220°C), as per basic principles of vaporization.

Why the others are wrong:

• A: Yeast does produce alcohol via anaerobic respiration in fermentation.
• B: Sugar is fermented into alcohol and CO2, not directly eliminating alcohol.
• D: Yeast in bread produces ethanol, not lactic acid (which is from bacteria in yogurt or sourdough).

Final answer: C