Jell-O Play Dough

This fun homemade dough can be played with and eaten! It is fully edible, and can be squished, rolled, and shaped. Try using molds or cookie cutters to shape it, or find simple tools to use such as forks, plastic straws, toothpicks, etc.

What You Need:

  • An adult’s help
  • Cooking pot or saucepan
  • Stove
  • Mixing spoon
  • 1 cup flour
  • 1/2 cup salt
  • 1 cup water
  • 1 tablespoon oil
  • 2 teaspoons cream of tartar
  • 1 (3.5 oz) package of unsweetened Jell-O

What You Do:

  1. Put the dry ingredients (Jell-O, flour, salt, and cream of tartar) in the pot and stir together.
  2. Measure the water in a 2-cup measuring cup, then add the oil. What do you notice about these two liquids?
  3. Put the pot with the dry ingredients on the stove and have an adult turn the burner on to medium heat.
  4. Slowly pour in the liquid ingredients.
  5. Stir the mixture constantly while it is cooking. Take turns with your adult helper if you need to. Keep stirring until the mixture gets thick and starts looking almost like mashed potatoes.
  6. Remove the pot from the heat. Turn off the stove.
  7. Let the mixture cool for about 15 minutes. Once it has cooled, knead it on a floured surface (such as a countertop or table). Knead the dough by pushing on it with your hands – first flatten the dough, then fold it up. Repeat this many times until the dough is not sticky and can be played with.
  8. Keep the dough in a sealed container when you have finished playing with it. It can keep for several weeks.

What Happened:

The play dough you made can be stretched, rolled, pushed, and pulled. It’s flexible and stretchy, yet it also holds its shape when you mold it. This happens because of a reaction (or chemical change) between the dry ingredients and the wet ingredients. The water and oil don’t mix – do they? It’s like they don’t like each other, and water doesn’t want to be near to the oil. When you mixed the water and oil in with the dry ingredients, something happened. The water mixed with the dry ingredients, and suddenly it didn’t mind being close to the oil. All of the dry and wet ingredients mixed together to make a thick solution.

Did you notice air bubbles in your homemade play dough? Between the bits of flour, water, oil, and Jell-O, there are tiny bits of air trapped inside. How did they get there? It happens because Jell-O contains an ingredient called gelatin. Gelatin is made up of long strands (almost like a necklace) of proteins. These protein necklaces stick together, making a stringy web. When you add water and heat, the webs become sticky, like a pile of spaghetti noodles. The Jell-O absorbs water, but it also traps air bubbles between the sticky strands of proteins. Even though your play dough feels smooth, the reason it can be stretched and rolled is because of these tiny strands of gelatin (so small you can’t see them) that hold everything together. The oil helps to keep the dough from being too dry. The cream of tartar keeps the dough from being too sticky and also works with the gelatin to make the dough light and fluffy.

Marshmallow Fun

Another kitchen ingredient that has gelatin is a bag of marshmallows! That is part of what makes marshmallows so light and fluffy. Here are some fun science projects you can do with this delicious treat.

Giant Marshmallows

  1. Put two marshmallows on a paper plate (or several paper towels). Microwave the marshmallows on high for about 60 seconds.
  2. Stand back, and watch what happens to the marshmallows. In about 20 seconds, you’ll see the marshmallows start to expand, puffing up to over three times their original size!
  3. When the minute is up, remove the marshmallows carefully, and let them cool. The marshmallows will shrink a bit once they come out of the microwave – but notice how they look different than when you put them in. Is the outside crunchy? Is the inside soft? Is part of the marshmallow hollow?
  4. Once the giant marshmallows have cooled, take a taste. Do they taste different than regular marshmallows?

Fluffernutter Dough

  1. Measure out 1/2 cup of peanut butter and put it into a bowl.
  2. Add 1/2 cup of marshmallow cream (such as Marshmallow Fluff or Jet-Puffed Marshmallow Creme).
  3. Mix the peanut butter and marshmallow cream together using a wooden spoon or spatula.
  4. When it is mixed together, play with your homemade dough. Try rolling it, stretching it, tearing, or making it into different shapes.
  5. When you are done playing with the dough, store it in a sealed container. It will last several days.

What Happened:

The two main ingredients in marshmallows (and marshmallow cream) are sugar and water. These sweets are light and fluffy because they have tiny bits of air trapped inside of them. When you put the marshmallows in the microwave, the air inside of them gets very warm. The sugar in the marshmallows also melts a little, becoming softer and more flexible. Have you ever heard that hot air rises? Hot air always wants to be on top. When you heat the marshmallows, the hot air pockets want to rise to be at the top. Since the marshmallow being heated in the microwave is soft and flexible, it stretches to allow the air inside to move. As the hot air is moving up, it pushes on the walls of the marshmallow, and the marshmallow gets much bigger, puffing up from the movement of hot air.

Along with sugar, water, and air, marshmallows contain gelatin. Remember that gelatin is like a long sticky string, or necklace? Gelatin is what makes a marshmallow hold its shape. There is not as much gelatin in marshmallows as there is in Jell-O, which means that marshmallows aren’t slippery and sticky like Jell-O is. To make a dough with marshmallow cream, we added another sticky ingredient: peanut butter. The oils in peanut butter, along with the sugar and tiny bits of air in the marshmallow cream, mix together to make a smooth, light, flexible dough to play with. Does it hold its shape well? If you use the fluffernutter dough to mold shapes with, you might notice that they lose their shape after a while. This is because the dough doesn’t have as much gelatin and can’t hold its shape as well as the dough made with Jell-O.

Homemade Butter

What You Need:

  • Whipping cream (at room temperature)
  • Small jar, like what baby food comes in

What You Do:

  1. Make sure that the whipping cream you’re using is at room temperature (not cold from the refrigerator).
  2. Put a few tablespoons of the cream into the jar. Put the lid on, and start shaking the jar. You can try rolling the jar back and forth with a family member, or take turns shaking the jar.
  3. Eventually, the cream will form into a ball. When this happens, you can pour off the excess liquid and then add a sprinkling of salt to your homemade butter.

What Happened:

Whipping cream is a dairy product that contains a lot of milk fat. Cream is made by skimming off the top of a large tub of fresh milk, where most of the milk fat has floated to the top. It is used to make whipped cream, ice cream, and butter. All the fat from the cream is contained in tiny droplets, like mini balloons too small to see. When you shake the jar, these balloons break open, letting the bits of fat go free. All the fat is collected together the more you shake it, and eventually it all comes together to form butter. Once the butter is made, there is still extra liquid in the jar. This is the leftover part of the cream, once the fat has been taken out. If you tasted it, it might taste a bit like milk, which has a lot less fat in it than cream does.

More Kitchen Science Projects:

  • Make candy with maple syrup – watch it crystallize!
  • The science of spinning eggs – you will need a partner to experiment with raw and hard-boiled eggs.