STEM Activity: Pop Into Science

When the weather begins to cool down for autumn, many farmers start getting ready to harvest their crops and store them for winter. Did you know that corn is one of the largest crops planted in the United States? Pop into the kitchen to explore the science behind two different ways of cooking a tasty snack food: popcorn!

Materials Needed:

• Bowls (two)
• Cooking pot with lid
• Measuring cups and measuring spoons
• Microwave
• Mixing bowl and mixing spoon
• Paper and pencil
• Paper bag
• Popcorn kernels (½ cup, divided in half)
• Salt
• Stovetop
• Vegetable Oil

Step-by-Step Instructions:

Part One: Make Popcorn in the Microwave

1. In a bowl, mix ¼ cup of popcorn kernels with a pinch of salt and 1 teaspoon of vegetable oil.
    
2. Place the kernels in a paper bag and seal the bag by folding the top down a few times.
    
3. Set the bag in the microwave and heat the bag for two to three minutes.
    
4. Listen for the pops! When there are a couple of seconds between each pop, remove the bag from the microwave.
    
5. Carefully pour the popcorn into one of your bowls.
    
6. Use a small piece of paper and write “Microwave” on it to make a label for this bowl.

Part Two: Make Popcorn on the Stovetop

1. Add 1 tablespoon of vegetable oil to the cooking pot, tilting the pot so the oil lightly covers the bottom.
    
2. Add ¼ cup of popcorn kernels to the pot and place the lid on it.
    
3. Ask an adult to help you cook the popcorn on the stovetop.
   • Place the pot on the stovetop and carefully turn it on and set it to medium heat.
   • When the popcorn kernels begin to pop, gently shake the pot to keep the popcorn from burning as it cooks.
   • When the popping slows down, and there are two seconds or more between pops, turn off the heat and remove the pot from the stovetop.
      
4. Pour the popcorn into your second bowl and sprinkle it with a pinch of salt.
    
5. Use a small piece of paper and write “Stovetop” on it to make a label for this bowl.

Part Three: Compare the Popcorn

1. On a piece of paper, draw two circles overlapping to create a Venn diagram.

2. Label one side of the Venn diagram “Microwave Popcorn” and the other side “Stovetop Popcorn.” Label the overlapping middle portion “Both.” 
    
3. Once all the popcorn has cooled down, try both kinds! 
    
4. Using your Venn diagram, write down your observations about each kind of popcorn under their labeled sections. Under “Both,” write observations that are true for both kinds of popcorn. 
    
5. Comparing their taste, texture, smell and appearance, place a star next to the method you think created the best popcorn.

What Are We Discovering?

When the water inside a corn kernel is heated, it turns into steam, which builds pressure inside the kernel. Eventually, the pressure becomes too much for the kernel to contain and it pops.

While there are many varieties of corn, not all of them can be used to make popcorn. In fact, there is only one type of corn with kernels that can pop: Zea mays everta.

By comparing two different methods of making popcorn, not only can you explore tasty everyday science, but you also can practice your decision-making skills. Being able to look at two choices and weigh the pros and cons of each is an important part of decision-making. Next time you need to make a choice, try using a Venn diagram to visualize all the factors.

There are lots of inventions that have been designed to improve the cooking and storing of food. For example, when you make popcorn in a microwave, you are working with the invention of National Inventors Hall of Fame^® Inductee Percy Spencer, who created the microwave oven in 1945. Today, millions of microwaves are used across the globe. Other food scientists have shaped the different ways to keep food fresh and safe to eat, like Inductee Mary Engle Pennington, who was a pioneer in food preservation and storage, or the food scientists at NASA who developed ways to transport food during the early days of space travel by compressing it into tubes or shaping it into cubes.

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