How Much Water Is in an Apple?

An Apple-Themed Science Activity

Weighing an apple
Getty Images/​iDymax 

Apple-themed activities don’t have to be limited to art projects for younger children. There are a number of apple-themed science activities that you can do with older children, too. By questioning how much water is in an apple, older kids can learn many science skills and use their reasoning powers.

How Much Water is in An Apple?

Apples, like many other fruits, have a high water content. The following experiment can help your child not only visualize, but also measure, exactly how much water is in an apple.

Goal of the Activity

To create hypotheses and participate in a science experiment to answer the question "How much water is in an apple?"

Skills Targeted

Scientific reasoning, scientific method, following an experimental protocol.

Materials Needed

  • A food scale or postal scale
  • Apple
  • Knife
  • Elastic band or a piece of string
  • Apple dehydration log: A sheet of paper or computer spreadsheet with lines for each apple segment, its initial weight, and its weight after two days, four days, six days, etc.

Procedure

  1. Start the activity by talking about what your child knows about the taste of apples. Different varieties have different flavors, but what do they have in common? One observation may be that they are all juicy.
  2. Cut the apple into quarters or eighths and remove the seeds.
  3. Weigh each of the apple pieces on the food scale and note the weight on the apple dehydration log, along with a hypothesis of what is going to happen as the pieces of apple are left open to the air.
  1. Wrap an elastic band around the apple pieces or tie a piece of string around them. Then, find a place to hang them up to dry out. Note: Putting the apple on a paper plate or paper towel won’t let apple slices dry out evenly.
  2. Weigh the apple pieces again in two days, note the weight in the log and rehang to keep drying.
  1. Continue weighing the apple every other day for the rest of the week or until the weight no longer changes.
  2. Add the beginning weights for all the apple pieces together. Then add the final weights together. Subtract the final weight from the beginning weight. Ask: What’s the difference? How many ounces of the apple weight was water?
  3. Ask your child to write that information on the apple dehydration sheet to answer the question: How much water is in an apple?
WeightsSlice 1Slice 2Slice 3Slice 4Total Weight
Initial     
Day 2     
Day 4     
Day 6     
Day 8     
Day 10     
Day 12     
Day 14     
Final     
How Much Water Is in an Apple? Initial Minus Final = Water:

Further Discussion Questions and Experiments

You can ask these questions to stimulate thinking about water in an apple:

  • Do you think drying the apple in a dehydrator to make apple chips would reduce the weight further?
  • What makes apple juice different from water? How much might those ingredients weigh?
  • Would the apple slices take shorter or longer to dry in different places? Discuss the refrigerator, a sunny window, a humid area, a dry area. You may run an experiment changing those conditions.
  • Do thinner slices dry faster than thicker slices and why?