Question

Your friend has added high concentration of sugar while baking the cookies, what will be its effect on the yeast action?

• A. Increase the yeast activity
• B. Retard the yeast activity
• C. Over fermentation
• D. Kills the yeast

Hint:

When making sweet breads (like Brioche), bakers often use special "Osmotolerant Yeast" which is designed to withstand high sugar levels.

Answer 1

The Correct Option is B

When you add a high concentration of sugar while baking cookies, it affects the activity of yeast in a specific way. Here is the explanation:

Yeast is a type of fungus that is commonly used in baking. It ferments sugar to produce carbon dioxide gas, which helps in leavening dough. The activity of yeast depends on various factors, including the concentration of sugar.

1. Yeast and Sugar: Yeast cells feed on sugars present in the dough. In moderate amounts, sugar provides a source of food for the yeast, enabling it to produce carbon dioxide and alcohol.
2. Effect of High Sugar Concentration: When there is a high concentration of sugar, it creates an osmotic pressure. This can draw water away from yeast cells, leading to dehydration.
3. Osmotic Pressure: The osmotic effect caused by high sugar can create an environment where yeast finds it difficult to thrive, as yeast cells lose moisture, which is critical for their activity.
4. Outcome on Yeast Activity: Due to the dehydration and osmotic stress, the activity of yeast is retarded rather than increased. This means that the high sugar concentration slows down the fermentation process instead of accelerating it.

Hence, the correct option is that high concentrations of sugar retard the yeast activity.