Popcorn, otherwise known as Zea mays everta, is a type of corn, and out of the four most common types of corn -- sweet, dent, flint, and popcorn -- it is the only type that pops. This is all thanks to its thinner hull, which allows it to break open.
What you may not realize it that this tasty snack is also a fantastic material for popcorn experiments. No matter if you want to just have fun at home or if you are trying to find some popcorn science fair projects, we have some a-maize-ing options!
Temperature Comparison Experiment
Most people store popcorn at room temperature in their pantries or kitchen cupboards, but what happens if your store popcorn in the refrigerator or the freezer? Does temperature affect popcorn's popping ability?
This experiment tests whether temperature affects the moisture levels of popcorn kernels. Set up for the experiment may take up to an hour. Then, the bags need to sit for at least 24 hours. Finishing the experiment will take approximately one to two hours.
This can make for a great popcorn science fair project for elementary-aged kids in grades three through five!
Materials
- 16 bags of the same brand and type of microwaveable popcorn
- Microwave
- Microwave popcorn popper
- Two quart measuring cup that is microwave safe
- Baking sheet
- Ruler
- Pen and paper
- Sandwich baggies
Instructions
- Measure out a small sample size of 50 kernels from each bag of popcorn. Place the kernels in a sandwich baggie. Make 15 baggies.
- Label each bag with a number so you can tell which is which later.
- Create a chart with a row for each baggie like so:
Volume Number of Unpopped Kernels Popped Kernel Size Bag 1 Bag 2 Bag 3 - Place five bags in the freezer, five in the refrigerator, and five at room temperature on the kitchen counter. Leave the bags for 24 hours.
- Preheat the microwave by heating a cup of water for one minute. Remove the cup carefully. This only needs to be done before the first bag.
- Remove a small sample of kernels from the extra popcorn bag and place them in the microwave popcorn popper. Set the timer for five minutes. When you start to hear the popping rate slow to about two to three seconds between pops, stop the microwave and note the time. Set the timer for this time for the entirety of the experiment.
- Take one bag from the freezer, place all the kernels in the popper, and pop for the set time from step six.
- Remove the popper and wait until all the pops have stopped.
- Empty the bowl into a two-quart measuring cup and record the amount in the "Volume" column of the data table.
- Pour the contents from the measuring cup onto a baking sheet and count the number of all unpopped kernels. Record the number in the data table.
- Using a centimeter ruler, measure the length of an average size popped kernel. Record the length in the data table.
- Repeat steps six through 10 with the remaining bags that were stored in the freezer, refrigerator, and at room temperature. Remember to test one bag at a time to ensure the kernels remain at their designated temperature for as long as possible before testing.
- Compare the data in the table and make conclusions.
Popcorn kernels have tiny drops of water inside them. As the popcorn is heated, the water expands, turning into steam at 212 degrees Fahrenheit and bursting around 347 degrees Fahrenheit. However, popcorn requires between 13.5 and 14 percent moisture to pop. The fridge and freezer both lower the moisture content of the popcorn kernels so your kids will see less popped kernels in these batches.
Popcorn Matters
What is a physical change versus a chemical change -- and how do they occur? Popcorn and marshmallows are great tools for teaching this chemistry lesson! For those who don't know, matter is everywhere, and it includes anything that takes up space and has mass. This includes both of these sweet and savory treats.
This experiment teaches kids about chemical and physical reactions and it will take less than an hour to complete. The experiment is ideal for the younger elementary-aged kids, but SUPERVISION IS REQUIRED.
Physical Versus Chemical Changes
The next thing you need to know before you begin is that there are five phases of matter: solids, liquids, gases, plasmas, and Bose-Einstein condensates. When a physical change occurs, only the appearance of the matter will be altered. When a chemical change occurs, you will notice a change in the flavor or smell of the food item.
By adding heat to popcorn kernels, the liquid inside them turns to steam and they pop, changing their physical state. In the case of popcorn, this is a permanent physical change, meaning you can't reverse the reaction.
Conversely, when you hold a marshmallow over a flame, it can either melt (another physical change) or it can burn (a chemical change). When the heat combines with the sugar in the marshmallow, water molecules are created, which then evaporate and create carbon. The carbon is the black residue you will see on the marshmallow's surface. When a substance changes or is created in a reaction, it is chemical change!
Materials
- Microwaveable popcorn bags or container of unpopped popcorn kernels
- Two Mason jars or tall clear drinking glasses
- Microwave
- Microwave popcorn popper (Only needed for unpopped popcorn kernels)
- Marshmallows
- Barbeque skewers
- Paper plate
- A flame (a gas stove or a lighter can both work)
Instructions Part One: Popcorn Changes
- Have children count two groups of 100 kernels of unpopped popcorn. (Note: Kids might want to count about 120 kernels for the popped popcorn group to ensure 100 popped kernels are available for the experiment)
- Place one group of unpopped popcorn in a Mason jar or tall drinking glass.
- Pop the second group of unpopped popcorn kernels using a microwave popcorn popper. Alternatively, pop a microwave bag of popcorn.
- Place 100 kernels of the popped popcorn in a Mason jar or tall drinking glass.
- Compare the two jars of popcorn kernels. Both are still popcorn. One sample is just inside out!
Instructions Part Two: Marshmallow Changes
- Parents should place two marshmallows on a barbeque skewer.
- Next, out of your child's reach, but close enough for them to see, hold the marshmallow end of the skewer over a flame, allowing the marshmallow to burn.
- Place the marshmallow on a paper plate and allow it to cool.
- Then, let your kids examine the cool, burned marshmallow and compare it to a fresh marshmallow from the bag.
- Make sure to point out both the color, texture and flavor changes of the marshmallow.
The best part about this experiment is that you can use the rest of the marshmallows to make tasty toppings for your popcorn and have the perfect afternoon treat!
Dancing Popcorn Experiment
This is another exciting popcorn experiment that shows off a chemical reaction! When you mix baking soda and vinegar, it produces carbon dioxide, which is a gas. When you mix these two compounds in water and drop in popcorn kernels, the popcorn will float up to the surface as the gas rises to the top of the glass. As the gas is released into the air, the kernels will drop back down to the bottom and the process will continue until all the gas is gone.
Materials
- Plain popcorn kernels (1/4 cup)
- A large, clear Mason jar or drinking glass (24 ounces)
- Spoon
- Baking Soda (2 tbsp)
- White Vinegar (6 tbsp)
- Water (3 cups)
The dancing popcorn experiment can be enhanced by adding in a few drops of food coloring to make a firework-like display as the kernels rise and fall through the water!
Instructions
- Fill your jar or glass with water, leaving a small amount of space at the top of the container.
- Add 5-10 drops of food coloring. (optional)
- Mix in your baking soda and stir until it's dissolved.
- Pour in your popcorn kernels.
- Add in your vinegar and get ready to watch your kernels dance!
Grow Popcorn
Popcorn doesn't grow in a microwave bag. It's a special form of corn that just happens to pop at high heat. It grows in the ground just like regular plants, making it the perfect project for young kids! Growing a popcorn plant is a simple experiment to introduce children in grades two through four the concept of seed germination. It also allows children to see what plants do underground.
This experiment takes about 30 minutes to set up, but it is a long-term project that will sit for a time while the plant grows. The plant will need occasional watering, and a possible replanting after a week or so. After a few days, children should see a root start to emerge from the seed, followed by a sprout in another few days. With adequate sunlight and water the seed should grow into a full grown popcorn plant.
Materials
- Popcorn seeds (Note: Most popcorn kernels sold in the supermarket will not grow so seeds should be purchased through a seed catalog)
- Clear plastic cup
- Paper towels
- Permanent marker
- Measuring cup
- Water
Instructions
- Fold a paper towel, so it is as wide as the cup is tall.
- Place the paper towel, so it snugly lines the inside of the cup.
- Place two to three popcorn seeds in the cup between the paper towels and the cup walls.
- Mark the date of the planting on the cup and the name of the child (optional) with a marker.
- Add some water to the bottom of the cup. The paper towel should absorb the water.
- Place the cup on a windowsill where the plant can get some sunlight.
- Observe what happens to the plant over the next few weeks.
Experiment Notes
- The popcorn seeds may need to be soaked in water for 24 hours before planting. Read the seed manufacturer's notes for recommendations.
- The paper towel should remain damp at all times, but it should not be dripping wet.
- If the plant grows too big for the cup, it can be replanted in a pot with soil.
Popping Science Fun
Popcorn can be used in many science experiments for kids. It's a simple and cheap material that can be used in a variety of ways to introduce basic science concepts like physical and chemical changes, seed germination, and science experiment design. These are just several experiments that can be done with young children. Get creative and make your own and then make yourself a healthy snack with the leftovers!