Hopping Grains

Hopping Grains

Learn how to make a handful of grains hop and dance with this simple kitchen experiment! Add in a splash of food coloring to create a cup that is mesmerizing to watch and enjoy.


Ages:
4 - 7
Est. Time:
<30 mins

How we did it:

Materials List

  1. grains - small, like Whole Grain Einkorn Wheat
  2. food coloring
  3. baking soda - 1 tsp
  4. vinegar - 1/4 cup
  5. glass
  6. water - 3/4 cup
  7. fork
  1. Fill a glass with ¾ of a cup of water.

  2. Stir in 1 teaspoon of baking soda.

  3. Drop in a few of the grains; they should sink to the bottom of the cup. If they don’t, head to the pantry and find something else to try. (We also got this to work with dry rice and small raisins.)

  4. Slowly pour in the vinegar. The mixture will fizz and your grains will begin to float up! 

     

    Keep watching the grains. Notice how they repeatedly float to the surface and then sink back to the bottom.

     

    (If the reaction doesn’t happen right away, give your cup a quick stir. If that doesn’t help, your grains may be too heavy to float. Try picking out the smallest ones, or look for a lighter grain.)


  5. To see what’s happening a little better, add a few drops of food coloring and watch how the color spreads through the mixture. 

     

    Eventually, the fizz will slow down and the grains will stop dancing. When this happens, you can add more baking soda and vinegar to the same cup, or dump it out and start with a fresh mixture.

     

    You can keep experimenting by testing out other materials in your cup. What happens if you drop in popcorn kernels? Rice? Bits of angel hair pasta? See what you can find in your kitchen that works!

     


    What’s going on?

    The lift that makes the grains dance comes from the reaction between baking soda and vinegar. As anyone who’s made a baking soda volcano knows, mixing those two ingredients creates bubbles — carbon dioxide bubbles, to be precise. These bubbles stick to the grains in the glass, lifting them up to the surface of the water. 

     

    But when the bubbles reach the surface, they pop. Without the bubbles to hold them up any more, the grains sink back down to the bottom. Then the whole process repeats, giving you hopping grains in a cup!