Reindeer Toothpaste Chemistry Demo for Kids

You turn an empty plastic bottle into a reindeer, then pour in the kid-safe elephant toothpaste mix: 3% hydrogen peroxide, dish soap, and food coloring, followed by yeast mixed with warm water. The yeast splits the peroxide into water and oxygen, and the soap traps the oxygen as a gushing stream of foam.

• Age: 4 and up to watch and decorate; an adult handles every chemical step
• Time: 15 minutes from setup to cleanup
• Mess level: medium, but contained on a tray

What Makes This the Kid-Safe Version?

Elephant toothpaste demos in science labs use peroxide many times stronger than the brown bottle in your medicine cabinet, and those versions are never kid activities. This demo uses only 3% hydrogen peroxide, the weak household kind. Even so, an adult pours the peroxide, everyone wears safety goggles, and nobody touches the foam until an adult rinses it. Kid-safe means adult-run.

What Supplies Does the Reindeer Demo Need?

Gather everything before you start:

• 1 clean, empty plastic bottle, 16 to 20 ounces, label removed
• 1/2 cup 3% hydrogen peroxide (the brown bottle from the medicine cabinet)
• 1 squirt liquid dish soap
• Red food coloring
• Green food coloring (optional, for a second eruption)
• 2 extra empty plastic bottles, any size (optional, for racing eruptions)
• 1 packet active dry yeast (about 2 teaspoons)
• 3 tablespoons warm water (warm like bath water, not hot)
• 1 small cup or bowl for the yeast mixture
• Funnel
• Measuring cup
• Tablespoon
• Safety goggles for everyone watching
• Large tray with raised edges (a baking sheet works)
• Googly eyes
• Brown construction paper
• Scissors
• Masking tape or clear tape
• Paper towels
• Old clothes or a smock
• Access to a sink or outdoor hose for rinsing

How Do You Turn the Bottle Into a Reindeer?

Do the decorating first, while little hands are excited and the chemistry is still put away:

1. Cut two antler shapes out of the brown construction paper with the scissors.
2. Tape one googly eye on each side of the bottle near the top.
3. Tape the brown construction paper antlers to the upper sides of the bottle.
4. Stand the finished reindeer bottle in the center of the tray.

The brown bottle color is already reindeer-perfect, which is half the charm.

How Do You Make the Foam Erupt?

From here on, a grown-up leads and kids watch from a step back:

1. Set the tray on the ground outside, or in the sink.
2. Put on safety goggles. Everyone watching wears a pair.
3. Pour 1/2 cup of 3% hydrogen peroxide through the funnel into the bottle. An adult does this pour.
4. Add 1 squirt of dish soap and 8 to 10 drops of red food coloring through the funnel. Swirl the bottle to mix the color in.
5. In the small cup, stir the yeast packet into 3 tablespoons of warm water for about 30 seconds. It looks like thin tan soup.
6. Pour the yeast mixture through the funnel into the bottle, pull the funnel out, and step back.
7. Watch the red foam gush out of the bottle and pile up on the tray. It keeps coming for 20 to 30 seconds.
8. When the show ends, an adult rinses the foam with water from the sink or hose, wipes the tray with wet paper towels, and rinses the bottle.

What Is the Science Behind the Foam?

Yeast holds a natural helper that breaks hydrogen peroxide apart into two things: water and oxygen. Inside the sealed brown bottle in your cabinet, that breakup creeps along unnoticed for months. The yeast speeds it up thousands of times, so all the oxygen rushes out at once. The dish soap catches the rushing oxygen and stretches it into foam. Tell kids: the yeast pops the peroxide like a balloon, and the soap blows the bubbles.

What If the Foam Is Weak or Overflows?

• Weak foam or no foam at all: the water was too hot and killed the yeast, or the peroxide bottle has sat open for months. Mix a fresh yeast cup with warm (not hot) water, and open a fresh brown bottle of peroxide.
• Foam overflowed the tray: the eruption is bigger than it looks in videos. Next time run the demo in the sink or pick a tray with higher edges.
• Pink foam instead of red: two drops of food coloring will not cut it. Use 8 to 10 drops for a true reindeer red.

How Do You Keep Everyone Safe?

Hydrogen peroxide handling is adult-only, every time, at every age. Goggles stay on from the first pour through the end of the eruption. Nobody touches the foam with bare hands until an adult rinses it with water, because the foam can irritate skin. Nothing from this demo goes in mouths: no tasting the foam, no sipping the peroxide. Run it on the tray, outside or in the sink. Rinse any skin the foam touches right away.

How Do You Turn One Eruption Into an Afternoon?

Run it again with green food coloring and compare the two reindeer side by side. Line up three bottles in different sizes and guess which one erupts tallest before you pour. Kids can wear their reindeer antler headbands while they narrate the eruption like sports announcers. For another sensory Christmas activity, try fake snow sensory play, or keep the reindeer theme going with reindeer handprint art.

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Frequently Asked Questions

What age is this demo best for?

Ages 4 and up with an adult running every chemical step. Toddlers and preschoolers make great audience members from a few feet back but should not handle the peroxide bottle or the yeast pour. School-age kids love decorating the reindeer and narrating the eruption. The adult-only rule on the peroxide stays firm at every age.

How messy is reindeer toothpaste?

Medium messy, but contained. The foam stays on the tray if your tray has raised edges, and red food coloring is the main stain risk. Put the tray outside or in the sink, wear old clothes or a smock, and keep paper towels close. Rinse skin right away if foam touches it, and wipe the tray down with a wet paper towel after the show.

How long does the whole activity take?

About 15 minutes. Decorating the reindeer bottle takes 5 minutes, mixing takes 5, and the eruption itself lasts under a minute. Cleanup is quick: rinse the bottle in the sink, wipe the tray with wet paper towels, and toss the used yeast cup in the trash. Short enough to hold a preschooler's attention from start to finish.

Is the foam safe to touch?

Not right away. The foam can irritate skin, so everyone keeps hands off until an adult rinses the foam with water from the sink or hose. Once rinsed, the leftover foam is soapy water and safe to touch. Never taste the foam or the peroxide, keep safety goggles on during the eruption, and rinse any skin that the foam touches.

This demo is part of our Christmas Sensory Pack collection of holiday ideas. Sign up for our newsletter and we will send you new seasonal activities as we publish them.

Be safe and have fun!