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

Children tasting limes in a kitchen

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All children have favorite foods and least favorite foods, but they may not know the words to use to describe those foods or understand how our taste buds work. A taste test experiment is a fun at-home experiment for all ages. Younger kids can learn about different flavors and learn the vocabulary to describe them, while older children can figure out for themselves which parts of her tongue are sensitive to which tastes.

Note: Mapping tastebuds will require placing toothpicks all over a child's tongue, including the back of it. This can trigger a gag reflex in some people. If your child has a sensitive gag reflex, you may want to be the taste tester and let your child take notes.

Learning Objectives

  • 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

Develop a Hypothesis

  1. Explain to your child that you are going to try out a bunch of different tastes placed directly on their tongue. Teach the words saltysweetsour, and bitter, by giving them an example of a type of food for each one.
  2. Ask the child to stick their 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 them to think about what happens to their tongue when they eat their favorite foods and least favorite foods. Then, ask them to make a good guess about how the tastes and taste buds work. That statement will be the hypothesis or the idea the experiment will be testing.

Steps of the Experiment

  1. Have the child draw the outline of a giant tongue on a piece of white paper with a red pencil. Set the paper aside.
  2. 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.
  3. Give the child some toothpicks and have them dip on in one of the cups. Ask them to place the stick on the tip of their tongue. Do they taste anything? What does it taste like?
  4. Dip again and repeat on the sides, flat surface, and back of the tongue. Once the child recognizes the taste and where on their tongue the taste is the strongest, have them write the name of the taste—not the liquid—in the corresponding space on the drawing.
  5. Give your child a chance to rinse their mouth with some water, and repeat this process with the rest of the liquids.
  6. Help them fill in the “tongue map,” by writing in all the tastes. If they want to draw taste buds and color in the tongue, have them do that, too.

    Questions

    • 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?