To conduct a yeast and sugar experiment, the things you will need are one packet of yeast, warm water, 2 tbsp of sugar, 1 large balloon and an empty plastic 16-oz. bottle. Blend the yeast, sugar and water in a ceramic container. If the mixture starts to fizz it means the yeast is consuming sugar and is thus producing carbon dioxide. Shift the mixture into an empty plastic bottle when the sugar and yeast have dissolved. Make sure to blow and stretch the balloon a few times so it can be easily expanded. Remove the cap and cover the opening of the bottle with the balloon. Notice the balloon slowly beginning to blow up; this happens due to the carbon dioxide created as the yeast consumes the sugar.
You can record the answers to different questions on the same experiments. These include the size a balloon expands to under different temperatures and the amount of gas created at each temperature. Do you get better results in the size of the balloon if you stretch the balloon before use?
Splenda and NutraSweet (sugar substitutes) can be substituted for sugar. Compare the results between substitutes and normal sugar. Instead of yeast, use baking powder and record the difference. Keep a record of all changes for accurate data.
Arrange two bottles with the same mixture of yeast, sugar and warm water. Place one bottle under a UV growth lamp and the other on a table at room temperature. Cover the bottles with similar balloons and look for any difference in size of the two balloons. For instance, you could measure the final growth of the balloon and how long it took for the balloon to grow. Record all your data.