A common science fair project using popcorn is one in which one variable in the popping process is changed. For instance, an experiment tests which of three brands of popcorn yields the most, either by weight or volume. Other variables that possibly affect how much popcorn is produced include age of the kernels, time for popping, the amount of air kernels have been exposed to during storage and storage temperature.
Once the corn has been popped, individual pieces are measurable. Therefore, science fair projects are able to determine results other than the total amount popped. These include the maximum size of individual popped corn, the average size of popped corn and the percentage or total number of popped or unpopped kernels.
It is possible for yield to be influenced by the method of popping: microwave, stovetop or air popper. These variations are also used to assess which type of popcorn is preferred by the most people. Preference is also measured for popcorn flavor, such as sweet versus salty and butter content.
A more elaborate project examines how water inside the kernel affects popping. Some kernels are heated in a 220-degrees Fahrenheit oven for two hours to dry them out. Others are soaked in water for the same amount of time. The yield for these variations is compared to the control group, the untreated popcorn.