Yeast

1
Yeast

• Chapter 21
• Leavening Agents

2
Do Now

• What is yeast?
• What foods is yeast used to make?

3
Yeast
4
Fermentation

• Yeast (Fungus) perform Fermentation
• Fermentation
• Reaction that splits glucose (__________) into
  carbon dioxide and ethyl alcohol

5
What two major foods/drinks use fermentation?
6
Why dont you get drunk off bread?
7
The Origins of Yeast

• Yeast was discovered thousands of years ago by
  accident
• Piece of yeast landed on dough and caused it to
  rise.

8
2 methods used to leaven bread (Ancient Egyptians)

• 1. Used a piece of leftover yeasty dough
• If dough was left out for too long, it produced a
  ___________ taste
• 2. Beer froth (foam that comes out of beer) was
  added to dough

9
Bread Fermentation

• In Bread the purpose of fermentation and yeast is
  to
• Yeast used is Saccharomyces cerevisiae
• Sold as granular and compressed forms

10
5 Ingredients used to make Bread

• 1.
• 2.
• 3.
• 4.
• 5.

11
Flour

• Provides starch and proteins used to make gluten

12
Liquid

• Typically mild or water
• Provides a medium to dissolve other ingredients
  and transports them to yeast cells

13
Salt

• Adds flavor
• Prevents enzymes from breaking down proteins in
  the bread

14
Sugar, Fat, and Eggs

• Sugars- helps crust to brown
• Fat- makes bread tender
• Eggs- richer in texture and flavor