Science Experiments for Kids: Sour, Sweet, Salty, or Bitter?

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Your child probably has favorite foods and least favorite foods, but she may not know the words to use to describe  those foods. A taste test experiment  is a  fun way to figure out which parts of her tongue are sensitive to which tastes.

It can also help her learn about  different types of flavors such as sour, salty, sweet, and bitter. For the most part, people taste sweet on the tip of the tongue, sour on the back sides,  salty on the front sides and bitter in the back.

WARNING: To map her taste buds, your child will be placing toothpicks all over her tongue, including the back of it. This can trigger a gag reflex in some people. If your child has, you may want to be the  taste tester and let your child take notes.

What Your Child Will Learn (or Practice):

  • Taste-related vocabulary
  • Taste bud mapping

Materials Need:

  • White paper
  • Colored pencils
  • Paper or plastic cups
  • Water
  • Sugar and salt
  • Lemon juice
  • Tonic water
  • Toothpicks

Creating a Hypothesis:

  1. Explain to your child that you are going to try out a bunch of  different tastes placed directly on her tongue. Teach the words  saltysweetsour, and bitter, by giving her an example of a type of food for each one.
  2. Ask your child to stick her tongue out in front of a mirror. Ask: What are the bumps all over your tongue are for? Do you know what they’re called? (Taste buds.) Why do you think they’re called that? ?
  3. Ask her to think about what  happens to her tongue when she eats her favorite foods and her least favorite foods. Then make a good guess about how the tastes and taste buds work. Her statement will be the  or the idea she is testing.

The Experiment:

  1. Have your child draw the outline of a  giant tongue on a  piece of white paper with a red pencil. Set the paper aside.
  1. Set up four plastic cups, each on top of a piece of paper. Pour a little lemon juice (sour) into the one cup, and a little tonic water (bitter) into another. Mix up sugar water (sweet) and salt water (salty) for the last two cups.  Label each piece of paper with the name of the liquid in the cup--not with the taste.
  2. Give your child some toothpicks and have her dip on in one of the cups. Ask her to place the stick on the tip of her tongue. Does she taste anything? What does it taste like?
  3. Dip again and repeat on the sides, flat surface, and back of the tongue. Once your child recognizes the taste and where on her tongue the taste is the strongest, have her write the name of the taste—not the liquid—in the corresponding space on her drawing.
  4. Give your child a chance to  rinse her mouth with some water, and repeat this process with the rest of the liquids.
  5. Help her fill in her  “tongue map,”  by writing in all the tastes. If she wants to draw taste buds and color in the tongue, have her do that, too.

    Questions to Ask:

    • Did the experiments answer the hypothesis?
    • Which area of your tongue detected bitter tastes? Sour? Sweet? Salty?
    • Are there any areas of your tongue on which you could taste more than one taste?
    • Are there areas that didn’t detect any tastes at all?
    • Do you think this is the same for everyone? How could you test that theory?