In an age-appropriate activity developed by a researcher-teacher team working together under the auspices of the American Chemical Science Coaches Program, middle school students at the Greensboro Montessori School (1) learned about the microbiological basis of fermentation, (2) learned about the chemical changes that take place during the fermentation of milk into yogurt, (3) applied this basic knowledge to designing and implementing experiments to test different conditions for culturing yogurt, (4) assessed the outcomes of different culturing conditions, and (5) developed a method for producing yogurt. This exercise includes hypothesis formulation, experimental design, and hypothesis testing and serves as an example of how empirically derived knowledge can be applied to the design of a food product.

We propose a procedure for the assay of fermentation in yeast in microcentrifuge tubes that is simple and rapid, permitting assay replicates, descriptive statistics, and the preparation of line graphs that indicate reproducibility. Using regression and simple derivatives to determine initial velocities, we suggest methods to compare the effects of experimental variables. This technique is straightforward enough to facilitate design of an inquiry lab based on a scenario that explores modifications to enhance the rate of fermentation.