Does Increasing Moisture Make More Popcorn Kernels Pop

Does Increasing Moisture Make More Popcorn Kernels Pop?

Introduction

Does increasing moisture make more popcorn kernels pop? This is a question that is important to the huge industry of popcorn growers and sellers. People who enjoy popcorn as a snack and are interested in getting the most popped kernels out of their bag of popcorn will also be able to relate to this subject. Popcorn is big business in the United States; Americans consume sixteen billion quarts of popcorn every year. In researching this question, it was necessary to find out about several related topics. Information on the structure and proper preparation of popcorn, phase changes, pressure, and the role of moisture in popping provide insight into this important question.

Although a kernel of popcorn would seem to have a very simple structure, a kernel actually has three parts. The outside of the kernel is called the pericarp. In everyday language this is the hull. It is a hard covering that protects the corn and makes it water-resistant. Inside the pericarp is the endosperm. This part is made of loosely packed starch which provides energy for the germinating seed (Woods, 2000). The endosperm may be hard or soft. Popcorn is a type of corn that has a particulary hard endosperm (Stone, 1992). Water or moisture is found along with the starch. Also located inside the pericarp is the germ. This is the only living part of the kernel and contains the genetic information, enzymes, vitamins and minerals for growth (Woods, 2000).

In order to effectively pop popcorn, three steps must be followed. First, oil must be heated. Butter should not be used because it will burn. The popcorn will pop best if the temperature of the oil is between 400 and 460 degrees Fahrenheit. Next, popcorn is added. Kernels should be added until there are just enough to cover the bottom of the pan. Shake the pan to coat the kernels with oil. Finally, kernels must have enough moisture to pop properly. Therefore, the popcorn should be kept in an airtight container. Moisture can be added if the popcorn is small or hully. This can be accomplished by filling a one-quart jar ¾ full of popcorn and adding one tablespoon of water. Cover, shake and let sit two to four days until the water has been absorbed (Stillman, 1989).

Since the water inside the popcorn seems to be important to the popping process, it is necessary to understand what happens when a liquid is heated. As a liquid, like water, is heated the molecules begin to vibrate faster. Faster moving molecules will spread out. Eventually the bonds that hold molecules next to each other will break, allowing them to spread out so far that they change into gas form (Johnson, 1995). This is an example of a phase change.

Because the pericarp or hull is hard and water resistant, this expansion of the water molecules will cause a build up of pressure inside the popcorn kernel. Pressure is stress exerted uniformly in all directions. It is measured in units of force applied per unit of area (Johnson, 1995). Inside the kernel the molecules of water bouncing into the inside of the pericarp puts a force or pressure on the inside walls of the popcorn kernel.

Moisture plays an important role in the popping of popcorn. Kernels have moisture inside. This water is stored in the endosperm. As the kernel is heated, the water inside expands, putting pressure on the pericarp or hull. When the pressure builds up enough, the kernel explodes turning the kernel inside out and fluffing out the starch stored inside (Wallace, 2000).

It has been shown that the pericarp and the endosperm are structures that are vital to understanding the explosion that occurs when popping corn. Knowing that water expands as it is heated creating pressure or a force on the inside of the kernel, provided a hypothesis: if the amount of moisture in a kernel is increased, more kernels will pop. In addition, the information about proper preparation of popcorn provided a method for changing the amount of moisture inside the kernels. It also provided instructions for making popcorn which were used in creating the experimental design. This research was necessary for the development of this experiment.

Bibliography

Johnson, Mary. Physics. New York: Doubleday, 1995.

Stillman, Phil. “Popping Great Popcorn.” (28 September 2001).

Stone, Elizabeth. “Growing Corn for Fun and Profit.” Organic Farming Today August 1992: 20-22.

Wallace, Henry. “What Makes Popcorn Pop?” Science in Our World September 2000: 58-59.

Woods, Alice. Botany for Beginners. New York: Random House, 2000.