Science project

Candy pH


  • Sour candies (Warheads, Sour Patch Kids, etc.)
  • Sweet candies (Pixie Stix, Jolly Ranchers, Smarties, etc.)
  • Chocolate candies (Hershey’s, Snickers, etc.)
  • Distilled water
  • pH paper
  • pH color chart
  • Small pot
  • Stirring spoon
  • Stove
  • Candy thermometer
  • Cooking spatula
  • Heat-proof gloves
  • Protective goggles
  • Pencil
  • Paper
  • Grown-up


  1. Arrange all your candies on a clean surface and take off their wrappers.
  2. Do a simple taste test. Which candy do you like the best?
  3. Take your notebook and pencil. Think about the two major elements of this project: candy and the pH scale. Scientists use the pH scale to measure the concentration of hydrogen ions in substances. The scale stretches from 1-14. Anything above 7 is considered alkaline; anything below is acidic.
  4. Which candy do you think will be acidic, or rank the highest on the pH scale? Write down your guess, often called a hypothesis, in your notebook.
  5. To test your candies, you'll need to melt them first. Grab your grown-up and make sure both of you put on goggles and heat-proof gloves. 
  6. Start with one type of candy: sour, sweet or chocolate. Drop a couple of handfuls of the candy into the small pot.
  7. Add in a cup or two of distilled water.
  8. Place the pot on the stove.
  9. Have an adult help you choose and set the correct stove heat. Hard candies should be heated over medium, but chocolate candies should be on a low setting.
  10. As you wait for the candy to heat up, keep your eye on the contents and stir frequently.
  11. Once the candy begins to liquify, carefully place the candy thermometer in the pot.
  12. When the hard candies reach about 300° F and the chocolate reaches 115° F, you can have your grown-up help you remove the pot from the stove.
  13. Quickly take a piece of pH paper and dip the end of it into the liquid candy.
  14. Take out the pH paper and wait.
  15. Once a color appears on the paper compare it to the pH color chart.
  16. Write down the results in your notebook.
  17. Repeat steps 6-15 with your remaining two types of candies. Make sure you diligently write down the results for each candy.
  18. When you're done, look over all your notes. Was the most acidic candy, sour, sweet or chocolate?


You should find that the sour candies are easily the most acidic and that all the candies measure low on the pH scale. 


To get to the bottom of this tasty science, let's take a closer look at sourness. What makes sour candies taste so sour? What is sour? Well, sourness is actually the taste that helps us detect acidity. Now it makes sense that the sour candies were the most acidic! Get out the sour candy package and check the ingredients. You should see types of acid listed right in the ingredients.

Sour candies aren't the only types of edibles that register low on the pH scale. Did you know that most food measures a bit more acidic than alkaline? That's why your candies—even the sugary sweet candies and the rich chocolate ones—all should have ended up with a pH number below 7. Do you think you could find the types of food that are alkaline? Try searching your own kitchen for these mysterious alkaline foods. Now that you know more about the pH scale, you're ready to tackle even bigger experiments!

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