Yeast Fun. 2.0 Flashcards
Basics and Bread
What are the different types of Commerical Yeast?
1) Fresh Yeast (or Compressed Yeast)
2) Active Dry Yeast
3) Instant Dry Yeast
4) Osmotolerant
How long will Fresh Yeast last?
- 2 weeks in the Fridge
* 4 months Frozen
What is the difference between Active Dry Yeast and Instant Dry Yeast?
Active Dry
- 25% of Yeast Cells are dead
- Needs to be Rehydrated and Activated (Fed) before use
- Not popular with Bakers
Instant Dry
- Newer (1970s)
- Does not have to be Dissolved in water before use (Hydrated) or fed
- Can be added mixed in with Dry Ingredients
- Absorbes water faster
- Produces more Gas quickly
- Contains very little dead Yeast: Less Yeast is needed
- Ideal for Short Fermentation or No-Time Doughs
Fermentation:
When Yeast acts on Sugars and changes them into Carbon-Dioxide Gas and Alcohol (Ethanol)
Three phases of the Basic Mixing Process:
- Blending the Ingredients
- Forming the Dough
3 Developing the Dough
What Processes occur during Mixing?
Air Cell Formation
Hydration: Water Absorption
Oxidation
Gluten Development
Coagulation:
The Firming or Hardening of proteins - Usually caused by Heat
Gultein and Gliadin:
Are two proteins found in wheat. When combined with water, they form a stretchable substance called GLUTEN
Gluten development can be controlled by….
1) Mixing Method
- proteins are hydrated
- air is mixed into dough
- gulten stands are developed
2) Leavening
- expansion of air cells stretch gluten and strengthens it
- tenderizes product by making cell walls thinner
3) Tempature
- warm temperatures promote yeast growth
What does Salt do?
Strengthens gluten and controls yeast growth
What effect does Bran have on Gluten Development?
Inhibits Gluten Development by cutting through web and preventing gluten from sticking together
Milk in Gluten Devlopement:
Milk contains an enzyme that interferes with Gluten Development
Ingredients for Adjusting Gluten Development:
Salt
Bran
Dough Conditioners
Milk
What are the 7 processes in Baking?
- Melting of Fats
- Formation and expansion of gases
- Killing of Yeast and Microorganisms
- Coagulation of Proteins
- Gelatinizarion of Starches
- Escape of water vapor and other gases
- Crust formation and browning
Cooling and Staling
- Starches continue to gelatinize
- Molecules bond with each other
- Becoming more Soild as cooling continues
( Retrogradation —-> Staling ) - Staling changes the texture and aroma because of structure change and lose of moisture