Does Tea Stain your Teeth?

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Updated on Apr 02, 2014

Grade Level: 6th - 10th; Type: Chemistry


Discover how long it takes to stain egg shells with coffee, tea, and cola.

Research Questions:

Teeth are structures in the mouth that are individually squares or cubical-shaped with grooves intended for use in breaking down food for consumption. Teeth are naturally white or off-white in color, but build-up from foods and drinks such as coffee and tea over time can stain the white color and turn teeth yellowish and discolored. In this experiment, we'll use egg shells in order to explore how teeth are stained by drinking coffee, tea, and cola.


  • Eggs, hollowed out following these instructions.
  • Coffee
  • Tea
  • Cola
  • Three large plastic containers

Experimental Procedure

  1. Fill three separate large containers with coffee, tea, and cola.
  2. Put at least one hollowed-out eggshell into each container.
  3. Every day, fish them out and observe the progress of discoloration.
  4. Take some photos of gradual changes. On the day when you really start to notice discoloration, note that day.
  5. Record your results and compare the effects of the three liquids.

Suggested Chart

Day #1
Day #2
Day #3



Terms/Concepts: Teeth; Enamel; Teeth Staining


Sofia PC is currently a college student with a deep interest in science who is aspiring to become a writer. She writes about all sorts of things across all subjects including, but not limited to; science, crafts, and fashion. She hopes to become a good writer so she can share her thoughts and experiences with the world and future generations.

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