This is one of the most creative projects I have seen in the past few years. The young student wanted to know if “stuff” — like bacteria — could be transferred from the sink basin to pasta when a pot of freshly cooked pasta was dumped into a colander sitting in the sink. As I am an avid pasta consumer, I too was interested in knowing his results.
BUT… not having access to a microbiology laboratory, John Paul could not answer the question directly. Many kids would have given up on this unique idea and would have started looking for a new project topic. John Paul –did not. He decided that all he had to do was find a different way to track the transfer of material from the sink to the pasta. In Part I of his project, he tried several materials to see which would be visible and quantifiable on the pasta. Eventually, he determined tea flakes would work well. This part of the project demonstrated creativity, critical thinking, and the scientific process. Scientists frequently have to use substitutes (i.e. proxies) because they are measurable when the variable we are really interested in is not measurable (or harder to measure, or more expensive, etc.)
Once he found a good surrogate for the bacteria, he asked a novel question: How does the size of the pot affect how much “bacteria” were transferred to the pasta. He hypothesized that the bigger pot would result in more tea flakes staying on the pasta. Although the average number of flakes was higher for the larger pot, one of the small pot trials resulted in the greatest number of flakes, so his results did not conclusively support his hypothesis. This is an interesting observation – because if it is NOT the volume of water, then what else could it be? Perhaps temperature of the water matters? Perhaps the way in which the pasta and water are dumped into the colander matters? Both of these are testable hypothesis for future experiments!
Overall, this is a great example of a clever solution for tackling microbiology questions. If you are not allowed to culture bacteria (and you are NOT allowed to at home or at school), then find something that will mimic the bacteria. John Paul used tea flakes, but I would guess glitter and pepper would also be a good substitute. TRY IT!