Yeast

Yeast

1. Raising Agents.

   • Biological
     • Yeast
   • Chemical
     • Baking Powder
     • Baking Soda
   • Mechanical
     • Whisking
     • Creaming
     • Sieving

2. Chemical Properties

   • Yeast when baking
     • Active Dry
       • Dehydrated, coarse granules which require activation in warm water with a pinch of sugar.
         • Cinnamon Rolls
         • Artisan Boules
     • Instant
       • Small, fine granules which can me directly mixed into dry ingredients without water first.
         • Bread Rolls
         • Quick Pizza Dough
     • Fresh
       • Soft, crubmly blocks that need to be crumbled into warm water/milk.
         • Croissants
         • Brioche

3. Functional Properties

   • Fermentation
     • Feeds on sugars and starches to produce CO2 and ethanol
   • Rising and Aeration
     • The generated CO2 gets trapped in gluten strands, making dough rise and expand when proving
   • Flavour Development
     • Fermentation produces minor amounts of acid, providing a tangy taste and a 'yeasty' smell
   • Texturising
     • Heat whilst baking causes the trapped air bubbles to further expand, creating a soft, airy and spongy texture

4. What is it?

   • A single-celled organism which needs food and moisture to survive

5. Working Characteristics

   • What it Needs to Work
     • Moisture
       • From added liquids like water or milk
     • Temperature
       • From the warm water/milk, the ambient air whilst proving and the oven heat
     • Food
       • From added sugar and starch from the flour