Many experiments benefit from the ability to take measurements continuously over a long period of time. Also, many sensors exist for use in biology that let you measure things you could never dream of measuring in the past. The fermentation of cabbage experiment This experiment uses CoachLab probeware to measure the pH level of 2 samples of cabbage for 24 hours. Each sample is sealed in a jar containing a salt-water solution. One sample is raw cabbage and the other has been cooked in boiling water for 15 minutes.
Students look at the pH data and compare it to the changes that have taken place in the samples.
They should hypothesize that it is the presence of bacteria on the raw cabbage that causes it to become sauerkraut. Students can then culture both cabbage samples, or look at them under a microscope, to prove their hypothesis. In this experiment, one head of raw cabbage was chopped into pieces about one inch square under sterile conditions. One sample of this cabbage was cooked in boiling water for 15 minutes and the other sample was not. Both samples were then placed into presterilized jars containing a salt-water solution.