What Makes Sourdough Bread Sour?

Sourdough bread has a rich history, dating back to ancient Egypt. It is unique due to its use of wild yeast and bacteria, which create its distinct sour taste through fermentation. Unlike modern yeast, sourdough requires a starter, a mix of flour and water that captures wild microbes. These microbes, including specific yeasts and bacteria, work together to ferment sugars, producing gases that make the dough rise. Research has identified unique species in sourdough, such as Lactobacillus sanfranciscensis, which thrive in acidic environments. Maintaining a starter involves regular feeding, and various factors can influence the bread's flavor.

What makes sourdough bread different from other types of bread?

• It uses commercial yeast.

• It is baked at a higher temperature.

• It is made with a mix of wild yeast and bacteria.

• It does not require any leavening agent.

How can you create a sourdough starter at home?

• By fermenting fruits.

• By mixing flour and water and letting it sit out.

• By buying a starter from the store.

• By using only water and sugar.

What is the role of yeast in the sourdough fermentation process?

• It prevents the growth of bacteria.

• It produces carbon dioxide gas that helps the dough rise.

• It gives the bread its sour taste.

• It adds sweetness to the bread.

Which bacterium was discovered in San Francisco sourdough starters?

• Lactobacillus plantarum

• Lactobacillus sanfranciscensis

• Lactobacillus acidophilus

• Lactobacillus casei

Why can the yeast in San Francisco sourdough survive in acidic environments?

• They produce their own acid.

• They are resistant to acid produced by bacteria.

• They consume all the acid.

• They neutralize the acid.