Does Temperature of Kernels Affect Popcorn Yield?
Does Temperature of Kernels Affect Popcorn Yield?
This experiment will attempt to determine if the temperature that popcorn kernels are stored at will affect the amount of un-popped kernels when using a hot air popcorn popper. Popcorn kernels contain moisture inside of them which, when heated, turns to steam and expands that in turn causes the kernel to explode. Popcorn.org states that loss of moisture content can cause less yield amounts when popping popcorn (popcorn.org, 2014). Literature Review
Popcorn is a favorite snack for many. There have been many experiments done on popcorn to determine best brands, best popping method and best way to yield the most popped kernels among others. Larano compared popping results with kernels stored at different temperatures. She reported that kernels stored in the refrigerator or freezer had more un-popped kernels than those that were stored at room temperature (Larano, 2002). Boyd tested two different brands of microwave popcorn to determine which produced the least amount of un-popped kernels. While Boyd tested by popping popcorn in the microwave and using two different brands of popcorn, he did state two explanations for why popcorn kernels don’t pop. One is that there is an insufficient amount of moisture in the kernel and the other that there is a crack in the hull that allows steam to escape before building up enough pressure to cause the kernel to explode (Boyd, n.d.). This experiment will focus on the difference in storing kernels at room temperature and in the freezer on the amount of un-popped kernels produced with a hot air popper. Experimental Design Steps
Using popcorn kernels from a store brand bag of popcorn kernels (all kernels should come from the same bag): Using baggies (or jars or bowels or some similar container), make six separate groups containing 300 kernels each Place three of the groups in a freezer and leave the other three on the counter or in a cabinet at room temperature Allow the groups to set for at least 24 hours
When ready to start the experiment, run the air popper for two minutes to warm it up Alternating between the groups placed in the freezer and the groups left at room temperature, pop each group in the air popper for two minutes into a large bowel or similar container After each group is finished popping, remove the popped kernels from the container and count the amount of un-popped kernels remaining (be sure to look in the popper for any un-popped kernels that may remain there) Reasoning
Running the air popper for two minutes before starting the experiment should allow the popper to be at a relatively constant temperature for each group. Alternating the type of group as the experiment is performed should prevent the results from being skewed due to the popper being hotter or cooler for one group type at the beginning or end of the experiment. Sequence of Events
The amount of un-popped kernels is determined by actually counting the number of un-popped kernels left for each group. All of the groups placed in the freezer will be at the same temperature and all of the groups left at room temperature will be at the same temperature. All groups will be heated in the same air popper for exactly two minutes. The un-popped kernels will be counted after removing the popped kernels from the container Tools and Technologies
Popcorn kernels (store brand)
Air popper (electric)
Large glass bowl
Iphone timer (minutes and seconds)
Independent variable: the temperature the popcorn kernels are stored at Dependent variable: the number of un-popped kernels left for each group Controlled variables: the number of popcorn kernels in each group. The heating time. The heating unit (air popper). Threat reduction to internal validity
Using the same number of popcorn kernels for each group ensures that each group starts with the same number of un-popped kernels. Using the same heating unit controls for the amount of heat applied to each group. Heating each group for the same amount of time controls for the duration of heat application. Alternating the types of groups (frozen and room temperature) avoids the effect of the air popper becoming hotter as the experiment progresses. Hypothesis
I think that the groups stored in the freezer will have more un-popped kernels than the groups stored at room temperature. This hypothesis was based on the reports of Larano that kernels stored at colder temperatures had more un-popped kernels than those stored at room temperature. Process of Data Collection
As hypothesized, the groups of kernels stored in the freezer had, on average, more un-popped kernels than the groups stored at room temperature. The frozen groups of kernels averaged 4 2/3 un-popped kernels, while the room temperature groups of kernels averaged 3 un-popped kernels.
Frozen Group #1Room Temperature Group #1
Data Table: Number of un-popped kernels with different storage temperatures Group # # Un-popped Kernels Frozen # Un-popped Kernels Room Temperature 1 4 3
2 7 3
3 3 3
The fact that there were very few un-popped kernels remaining for all groups shows that 2 minutes is an appropriate amount of time to heat the kernels. The fact that the number of un-popped kernels were fairly close for all groups indicates that the number of starting kernels may need to be modified. A larger amount of starting kernels may be necessary to see more of a difference in un-popped kernels. Results
The graph above shows that, on average, there were more un-popped kernels for groups stored in the freezer versus groups stored at room temperature. Conclusion
Confirmation of Hypothesis
The results above confirm that popcorn kernels stored in a freezer will leave more un-popped kernels than kernels stored at room temperature will. The frozen groups averaged 4 2/3 un-popped kernels, while the room temperature groups of kernels averaged 3 un-popped kernels. Experimental Design as a Key Factor
The design of an experiment will establish whether the results will be consistent in their quality. If more than one independent variable is present in an experiment, the causes of any variations in measurements will be indeterminable. Results must be able to be measured in a reliable way in order to determine if the independent variable is the cause of the variation in measurement. Having good controls on all variables will prevent outside factors from interfering with the results. Without good controls the results of the experiment will be unverifiable. Replication
To replicate this experiment, the groups must be stored in their storage location for at least 24 hours prior to the actual experiment taking place. Each group must have the same number of popcorn kernels to start out with. It is also important that each group be heated in the same heating unit and for the same amount of time. Evaluation of Validity
Replicating this experiment would help to validate it. If more scientists were to repeat this experiment and obtain the same results it would give credence to this experiment. If this experiment were not able to be replicated consistently, it may be invalidated.
Boyd, S. (n.d.). The jawbreakers of the popcorn industry. Retrieved from http://home.ptd.net/~sequoia1/Science/popcorn.htmLarano, M. (2002). Pop! Go the kernels. Retrieved from https://www.usc.edu/CSSF/History/2002/Projects/J0920.pdf