to demonstrate fermentation and gas production.
One Important Thing: Don’t Taste It
If you don’t know what was added to the bottle, don’t drink it or taste it to figure out what it is.
The safest approach is to ask your niece what the experiment is and what ingredients she used.
If it is an active fermentation, the container can also produce gas and pressure, so it shouldn’t be tightly sealed without an appropriate way for gas to escape.
What About the Giant Balloon?
That’s actually consistent with the basic
