1. Ingredients and Food Science
Yeast Breads
Ingredients and Food Science

2. Basic Ingredients Yeast bread has 6 basic ingredients Flour Liquid
Salt
Yeast
Fat
Sugar
OPTIONAL
Eggs

3. Flour Flour give structure/body to bread because of the protein gluten
When flour is thoroughly mixed with a liquid and kneaded, gluten is formed and able to support CO2 produced by yeast
Gluten becomes more elastic as flour is manipulated or kneaded
(Example: gluten is like bubble gum – when you first put it in your mouth, it is soft and chewy, it becomes more elastic as you chew, so you can blow bubbles. If you chew it for too long, it gets tough and hurts your jaw.)

4. Yeast Yeast is a living organism, a one-celled fungus
Feeds on carbohydrates (sugar, flour) and converts them to carbon dioxide (CO2) and alcohol during a process called fermentation
Yeast is a leavening agent.
Leaven means to make light and porous
It works best at room temperature and dies at high temperature and activity slows at low temperatures
Yeast is purchased in a dry, granular form, as a compressed cake, or in an instant form
Compressed yeast requires refrigeration, but granular yeast keeps well on the shelf. Instant yeast requires no prior handling and may be added directly to the dry ingredients. Some flours are self-rising meaning yeast has already been added and, therefore, no additional leavening agents are necessary.

5. Liquid Water or milk are typically used as the liquid in yeast breads
Purpose is to moisten, dissolve, and combine the other ingredients
Milk adds nutrients

6. Salt Without salt, yeast dough is sticky and hard to handle
If left out of the recipe, the baked bread will have small holes on the bottom and outside of the product

7. Sugar
Sugar provides extra food for the yeast, so the dough rises faster
If too much sugar is added, however, the yeast works more slowly
Sugar helps bread to brown and adds flavor and tenderness to the dough

8. Fat
Fat is a tenderizer
It traps air and causes the dough layers to separate

9. Eggs When beaten, eggs incorporate air
They add flavor, color, and strength due to protein content

10. Food Science Principles
Kneading
Working the dough to develop gluten
Add just enough additional flour to prevent sticking
Develop a rhythm to kneading
Fold dough in half toward the body, push against the dough with heel of hands and continue until the dough becomes smooth and elastic

11. Food Science Principles
Fermentation
The process by which yeast converts sugar into carbon dioxide and alcohol
It also refers to the time that yeast dough is left to rise

12. Food Science Principles
Shaping
Forming dough into desired shape – loaf, rolls, etc.

13. Food Science Principles
Proofing
Final rise of shaped or panned yeast products before baking
Proofing should continue until the product is doubled in size
Underproofing = poor volume and texture
Overproofing = sour flavor, poor volume, and paler color after baking

14. Food Science Principles
Baking/Oven spring
As yeast breads bake, a variety of chemical and physical changes turn dough into an edible product
Gases form, gases are trapped, starches gelatinize, proteins coagulate, fats melt, water evaporates, sugars caramelize
Oven spring
Because of the expansion of gases, yeast products experience a sudden rise when first placed in a hot oven. This rise is known as oven spring.