Fermentation in a Bag

Great Lakes Bioenergy Research Center, U.S. Department of Energy

This is a hands-on inquiry activity using zip-lock plastic bags that allows students to observe the process of fermentation and the challenge of producing ethanol from cellulosic sources. Students are asked to predict outcomes and check their observations with their predictions. Teachers can easily adapt to materials and specific classroom issues.

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Notes from our reviewers

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Consider an engagement piece and wrap-up piece that clearly connects the activity to energy and various fuel sources. Would fit nicely into activities investigating respiration and making connections between respiration and larger energy topics. If no ethanol probe, just ask kids to open bag and "waft" odors from the bag. They should be able to pick up an alcohol smell. Educators are encouraged to use re-usable containers instead of a plastic bag to minimize plastic waste.
Students combine yeast and warm water with a feedstock in a "snack" size resealable zipper bag and observe as the yeast "eats" the feedstock such as sugar, cornmeal, or sawdust, and produces carbon dioxide and ethanol. Younger students can observe fermentation in a single bag, while older students can create multiple set-ups to compare how yeast reacts with different feedstocks. Comments from expert scientist: This activity introduces students to fermentation of different feedstocks in a fun and inexpensive way. The goals of the study are clearly defined, the methods are simple yet relevant and well laid out, and the data analysis the students are to perform depends on how in depth the instructor would like to go with the experiment. This activity is very well thought out and obviously made by people with both scientific expertise and teaching experience. Instructors get to choose how detailed they would like to go within this activity because it has three opportunities: basic experiment, master experiment, and a science fair extension.
Explicit instructions for teachers are included. Support materials are included that enrich and support the experiment (data sheets, labels, posters etc.) Excellent student handouts. Very simple and illustrative hands-on activity. Easily adapted to suit specific needs of the the classroom. Science content-based power points and videos are included on the Great Lakes Bioenergy site.