Name(s): _____________________________________________ Date:_____________________
Barf Bag: Alcohol Fermentation Lab
Objective: To observe the effect of food sources on the process of
fermentation by yeast.
Essential Question: How does sugar affect the rate of CO2 production
during fermentation?
❑3 plastic bags (pint)
❑3 types of cereal (need to have different amounts of sugar content)
❑Dehydrated yeast
❑warm water
❑Timer
❑Heat source (i.e. incubator, heat lamp)
Procedure:
1. Label your plastic bags with the cereal brand.
2. Obtain 1 dixie cup full of of each brand of cereal, crush it up, and place in a bag.
3. Add about 100-130mL of warm water (115 F) to each bag.
4. Then, add 1 tsp. of yeast to each bag.
5. Carefully compress all the air out of the bags and seal the bags tightly!
6. Gently shake/squish the bag so that all of the contents mix.
7. Allow the bag to rest in a warm environment for at least 30 minutes.
1
Cereal
Brand
_________
Background Information:
Yeast are tiny unicellular fungi. Yeasts cannot make their own food, so they
need to consume food for energy. They rely on sugar found in their
environment to provide them with the energy that they need to grow and reproduce.
Yeast can utilize aerobic respiration but can also utilize fermentation when oxygen isn’t
available. When yeast is used to make bread, for example, the yeast will use up the available
oxygen inside the dough very quickly and will then use only fermentation.
ATP will be made via glycolysis, which requires no oxygen. After glycolysis the yeast will
remove a CO2 from the pyruvate which will be used to oxidize NADH to NAD+.
Today, we will experiment to determine if different amounts of sugar have an effect on CO2
production. This determination will be made based on observation of the quantity of products
produced during a chemical reaction. The plastic bag will be used to house our chemical
reaction.
Materials:
2
Cereal
Brand
_________
3
Cereal
Brand
_________
