Gummy Bear Science Fair Project | Complete Guide

The “Gummy Bear Osmosis” experiment is a classic, colorful, and highly effective science fair project. It demonstrates the concept of osmosis (how water moves through membranes) in a way that is easy to see and measure.

Here is a complete guide to setting up this project, structured like a winning science fair entry.

1. The Core Question

• Title Idea: “Growing Gummy Bears: How Do Liquids Affect Size?”

• Problem Statement: How does the type of liquid affect the size and mass of a gummy bear?

• Hypothesis: If I put a gummy bear in plain water, then it will grow the largest because water will move into the candy to balance the sugar concentration.

2. The Science (What is happening?)

You need to explain Osmosis.

• Gummy bears are made of gelatin and sugar. They act like a sponge.

• The skin of the gummy bear is a semi-permeable membrane. It lets water pass through, but not the sugar inside.

• Hypotonic Solution (Plain Water): There is more water outside the bear than inside. Nature wants to balance this, so water rushes into the bear, making it swell.

• Hypertonic Solution (Salt Water): If the water is very salty, it might draw water out of the bear (or keep it from growing much), causing it to shrink or stay the same size.

Also Read : Science Fair Ideas For 7th Grade

3. The Experiment

Materials:

• 4 clear cups or jars

• 4 Gummy Bears (same color/brand)

• Liquids: Tap water, Salt water (mix 2 tbsp salt in 1 cup water), Vinegar, Soda (e.g., Sprite)

• Ruler and Kitchen Scale (for data)

• Paper and pencil

Procedure:

1. Measure (Day 0): Measure the length, width, and weight (if you have a scale) of each gummy bear before putting them in liquid. Record this as “Starting Data.”

2. Label: Label your cups (Water, Salt Water, Vinegar, Soda).

3. Submerge: Place one bear in each cup and fill with the corresponding liquid.

4. Wait: Let them sit for 12–24 hours.

5. Measure (Day 1): Gently take them out. They will be fragile! Measure and weigh them again.

6. Compare: Calculate the change. (e.g., Final Length minus Starting Length).

4. Expected Results

• Tap Water: The bear will grow massive (sometimes 3x the size) and might become clear/jelly-like.

• Salt Water: The bear will usually stay small or shrink slightly.

• Vinegar: The bear will grow, but the acid might dissolve the gelatin, making it lose its shape or turn into goo.

• Soda: It will grow (because of the water content) but maybe less than plain water due to the sugar already in the soda.

5. How to Make It a “Winning” Project

Judges look for data and controls, not just big candy.

• Use a Control: Keep one gummy bear dry on the table. This proves that air didn’t make them change.

• Graph Your Data: Make a bar chart showing the “Percent Change in Weight” for each liquid.

• Repeat: Do the experiment 3 times for each liquid (3 cups of water, 3 cups of vinegar) and take the average. This makes your results scientific, not accidental.

6. Variations for Different Grades

• Younger (K-3): Focus on observation. Draw pictures of the bears before and after.

• Older (4-8): Focus on math. Calculate the volume ($L \times W \times H$) and the percentage of growth.

• Advanced: Test different concentrations of salt. At what point does the salt water stop the bear from growing? (This finds the “isotonic” point).

Data Table template

Here is a ready-to-use Data Table template for your Gummy Bear project. You can draw this in your notebook or print it out for your display board.

Gummy Bear Data Table

How to Calculate the Results

For the “Change in Size” column, use this simple formula:

(Example: If it started at 2 cm and ended at 5 cm, then $5 – 2 = 3 \text{ cm growth}$)

Advanced: Calculate Percentage Change (For Extra Credit)

Judges love it when you calculate the percentage, because it shows exactly how much it grew relative to its original size.

Example:

• Start: 2 grams

• Final: 6 grams

• Math: (6 – 2) \ 2 = 2. Then 2 X 100 = 200% Growth

Next Step:

Once you fill this table out, you can use the “Change in Size” or “% Change” numbers to create a Bar Graph! Would you like tips on how to label your graph axes correctly?