Chameleon Eggs

    Kids, have you seen those drinks with the floating edible eggs or beads in them?  You can apply chemistry to make edible eggs or beads, and you can even make them change color.

    You’ll need:

    • 1 tablespoon sodium alginate
    • 1 tablespoon sugar
    • 1-2 teaspoons baking soda
    • 1 can frozen concentrated grape juice
    • 1 teaspoon calcium chloride
    • 3 antacid tablets (with magnesium hydroxide)
    • large glass, spoon, pipette or dropper, jar with lid, strainer or slotted spoon

    Please note:  All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.

    Make the Eggs

    1. Mix together the sodium alginate and sugar.
    2. In a separate container, add baking soda to the grape juice, a pinch at a time. Stir and wait until no more bubbles form before adding a pinch more baking soda. Continue this until very few bubbles form. The alkaline baking soda is neutralizing the acidic grape juice. You want to neutralize the grape juice because you need a higher pH in order to dissolve the sodium alginate.
    3. Pour the sodium alginate and sugar mixture into the jar. Stir in the neutralized grape juice.
    4. Tighten the lid on the jar and shake it to thoroughly mix the contents. Allow the jar to sit overnight so that the sodium alginate will become fully hydrated.
    5. Crush the antacid tablets and mix them together with the calcium chloride.
    6. Stir the calcium chloride and antacid into a large (12-16 oz) glass of water.
    7. Now comes the part where you make the gel beads! Use the dropper or pipette to suck up some of the grape juice solution. While stirring, slowly drip the juice solution into the glass of water, calcium chloride and antacid. Drip the grape juice solution into the glass from above -- if the dropper comes into contact with the antacid solution then the grape juice solution will solidify in your tube.
    8. Leave the eggs or beads in this solution until they turn blue.

    Color Change Gel Eggs

    Use a slotted spoon or strainer to remove a spoonful of the gel eggs. Add them to an acidic drink, like lemonade or lemon-lime soda or white wine and watch the acidity of the drink change the color of the eggs from blue to red! A carbonated beverage is extra fun because the gel eggs will float up and down with the bubbles.
    Supplies:  Sodium alginate can be found in grocery and health food stores. Frozen, concentrated, deeply-colored grape juice is best; bottled concentrate is ok. Calcium chloride is at grocery stores where the pickling and canning chemicals are sold, or from home supply stores in the dessicant area.


    Kathleen Carrado Gregar, PhD, Argonne National Labs
    March 2012



    Anne Marie Helmenstine at Chemistry