Monday, September 27, 2010

A Mummified Apple

Last Monday we started an experiment to determine what mixtures of baking soda (natron), iodized salt and Epsom salt would best mummify a slice of apple.

We had the following combinations and apple slice weights (weighed with a control-weighted object):

Control (plain apple): 8 oz.
1/2 c. baking soda: 8 oz.
1/2 c. iodized salt: 8 oz.
1/2 c. Epsom salt: 8 oz.
50:50 baking soda and iodized salt: 8 oz.
50:50 iodized salt and Epsom salt: 9 oz.
50:50 baking soda and Epsom salt: 9 oz.
Equal portions baking soda, iodized salt, Epsom salt: 8 oz.

We put the apples aside for one full week and then inspected them this morning.

Question: Which substance combination will mummify the apple more?

Background Research: When Egyptians first started the mummificaton process, they used natron (baking soda) to dry out the body. Over the years they perfected their processes, using other salts.

Hypothesis: Dawson predicted that the combination of Epsom salt and iodized salt would do the best job of mummifying the apple. I predicted that the combination of baking soda and Epsom salt would do the best job of mummifying the apple.

Analysis and Observations: After one full week Dawson shook off the salts and weighed each apple slice. The Control did not lose any weight. Some of them lost exactly 1 oz. Others lost 1 1/2 ozs. Some had mold. Some were very browned. Some were significantly dryer but still the full color of the apple. These were the main observations about the substances:
  • The natron did the worst job of drying out the apple and was a poor preservative as each apple with natron was molded.
  • The Epsom salt was an excellent preservative, but didn't dry out the apple as much as the iodized salt.
  • The iodized salt dried out the apple significantly, but didn't do as good a job preserving it as it did when mixed with Epsom salt.
Conclusion: The 50:50 mixture of iodized salt and Epsom salt did the best job mummifying the apple, both in drying it out and in preserving it. Dawson's hypothesis was correct.

Here are some "yummy" pictures of the mummified apple slices! Pie anyone?

This was a great experiment! You can go here to do it yourself.


  1. I'm not a parent and I'm not homeschooled but this website has helped me alot for my science project at school! Thanks!

  2. you did not yous backing soda my class is useing backing soda i whant to know why

  3. same here

    in reply to alex

    1. I did use baking soda. I followed the experiment exactly as set forth in the provided link.

  4. I did this with my children for 12 days & baking soda mixed wit table salt did the best for us


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