======Yeast and Bread Fermentation======


<WRAP right box>
**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
\\
**Categories:** {{$demo.categories}}
\\


**Alternative titles:** Bread in a Bag: Yeast and Dough Rising
</WRAP>

====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Prepare bread dough ingredients in a sealed plastic bag and knead until combined.  
  - Allow the dough to sit and observe how its volume increases during proofing as yeast ferments sugars.  
  - Store the dough in the refrigerator if the experiment continues to another day.  
  - Bake the dough in an oven.  
  - Record observations of dough before and after, noting changes in texture, size, and structure.




====Links==== 
20-Minute Mini Lab: Explore Yeast, Bread and Fermentation  - Bite Scized Education: 
{{youtube>y_1L9Ibsqgo?}}\\

====Variations====
  * Compare dough proofed at room temperature versus refrigerated dough.  
  * Test different types of flour or sugar sources.  
  * Allow dough to rise for different lengths of time and compare results.  
  * Substitute yeast with baking powder or baking soda to compare leavening methods.



====Safety Precautions====
  * Wash hands before and after handling dough.  
  * Clean surfaces and utensils to avoid contamination.  
  * Use oven mitts and caution when handling hot baking trays.  
  * Ensure students do not consume raw dough.




====Questions to Consider====
  * Why does the dough expand in volume as it sits? (Yeast ferments sugars, producing carbon dioxide gas that gets trapped in the dough structure.)  
  * What environmental factors might change the rate of fermentation? (Temperature, sugar type/amount, oxygen availability.)  
  * How is yeast similar to and different from other living organisms? (It is a microbe that respires and consumes nutrients but is a single-celled fungus rather than a multicellular organism.)