Have you ever wished your candy were bigger? An easy way to grow a gummy bear or any other gelatin-type sweet is to put it in water. The caramel will rise but it may not taste as good!
Water enters the gummy bear through a process called osmosis. Osmosis is the movement of water through a semipermeable membrane from an area of high water concentration to an area of low water concentration. Water moves across the membrane until the water concentration is the same on both sides.
We designed an investigation to find out what happens to a gummy bear in running water and salt water.
You will need to
Gummy bears or other gelatinous sweets
Water
Salt
Spoon
Kitchen scale – optional
Small bowls or cups
Instructions
Add enough water to two small bowls to cover the gummy bear completely. Each container must contain the same amount of water.
Add a tablespoon of salt to a bowl and stir well.
Weigh each gummy bear and record the weight.
Place a gummy bear in each container.
Keep a third gummy bear aside. This is the control gummy bear.
Check every 30 minutes for about 3 hours.
Weigh the gummy bears again.
You should find that the gummy bear in plain water increases in size, and the gummy bear in salt water shrinks or stays the same size.
The largest gummy bear was the one soaked in running water and the one at the bottom was the control.
Extension tasks
Add the expanded gummy bear to the salt water and let it sit for several hours. It should shrink again as the water leaves the gummy bear and enters the salt water.
Set up an investigation with a series of bowls containing different amounts of salt. See what happens to each gummy bear!
What's happening
Gummy bears and other jelly sweets are made primarily from water, gelatin and sugar. The concentration of water inside the gummy bear is low compared to that outside, so the water passes into the candy by osmosis. This is why the gummy bear in the water increases in size.
The concentration of water in the salt water is probably similar to that inside the gummy bear, so the gummy bear doesn't increase in size. If you salted the water more, the gummy bear might shrink as the water leaves the bear and enters the water.
More scientific ideas
Learn more about osmosis with eggsIf you remove the shell of an egg with vinegar to reveal the membrane and place it in water, the egg will increase in size as the water enters the egg.
Build candy towers, a candy house, try candy chromatography and more with my collection of scientific experiments on sweets.
Last updated on February 16, 2024 by Emma Vanstone
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