The top image shows the beginning of fermentation after 5 minutes. The bottom image, taken after 20 minutes, shows the bag with the sugar feedstock full of CO2 gas, while the wood shavings bag is flat.Organisms use the metabolic process of fermentation to convert sugars into acids, gases or alcohol. Fermentation is used for making popular foods like yogurt, cheese, beer and wine. Fermentation by yeast and bacteria is one of the processes used to make ethanol biofuel. In this experiment students will observe and measure evidence of chemical changes caused by fermentation. They will test multiple feedstocks (starting materials) and compare how yeast ferments sugar, starch and cellulose-based biomass (cellulose is a complex polymer made from many glucose molecules and is found in plant cell walls). This experiment also provides insight into the fermentation process and the challenge of producing ethanol and other biofuels from cellulosic materials. 

For additional Bioenergy lessons visit:


LS1.C, HS-LS1-7 

Grade Level Range: 
Middle School (6-8)
High School (9-12)