Exploring Acid–Base Chemistry by Making and Monitoring Red-Cabbage Sauerkraut: A Fresh Twist on the Classic Cabbage-Indicator Experiment

Naturally occurring anthocyanin indicators have been used for many years to introduce science students to acid–base concepts. A classroom activity has been developed that uses naturally occurring anthocyanins to monitor the pH changes associated with the fermentation of red cabbage to sauerkraut by lactic acid bacteria. Through the activity and related discussion, students are introduced to the scientific method, basic laboratory practices, acid–base chemistry, chemical and physical changes, fermentation, and microbiology. Although this activity and accompanying assignments are designed for students ages 6–12, the activity is adaptable to students of all ages and backgrounds.