What is the best insulator?

For week four of class the task was to test four different materials to be used as insulators of cups of hot water. Each cup had the same amount of hot water and were lined up side by side on the counter. The only difference was the material chosen to cover each cup. For my materials I chose a Ziploc bag, Aluminum foil, a sheet of paper towel folded into four, and a Styrofoam plate. Prior to setting up the experiment I hypothesized that the aluminum foil would be the best insulator because of its use as a conductor of heat as well. However, after having the water sit the required 30 minutes I checked the temperature with a basic thermometer and lo and behold I found that the best insulator of the items I selected was the Ziploc bag. Coming in a close second was the Styrofoam plate. I was more than a little shocked that the Ziploc bag did the better than the aluminum foil which is used in kitchens across the country, and I dare say across the world. I recall my mom sending food to neighbors who were shut in and the food would be covered in foil to seal in the heat. Maybe I should tell my mom to use Ziploc bags next time.

This experiment led me to question if the same would be true with other materials that needed to stay warm. What about pizza or hot wings? I believe that because those food items are solid they will maintain their heat much better and the best insulator for these items may very well not be a ziplock bag. I will post an update to this blog once I have completed the same experiment with either pizza or hotwings. As is I may have to convince my hubby to throw out the well balanced dinner plans one night so that I can run my experiment.