The Setup

Have you ever seen the Coke dropped in mentos experiment? Well, I hadn’t. The idea had come up in a couple of conversations in the past few days, so we decided to try it. BUT, we didn’t stop there. We decided to compare a store-brand coke with the real Diet Coke. After getting the supplies at the store, the kids came up with hypothesizes, and attempted the experiment.

Harrison (me): My hypothesis was that the real Diet Coke was going to shoot twice as high.
Storybird: Storybird’s hypothesis was that the real stuff would empty the bottle twice as fast.

We brought the bottles one by one out to the end of the dock and dropped a Mento in each bottle.

Result: This was rather disappointing. Both brands shot about the same height, but it was only as high as my waist.

Conclusion: The off-brand soda was about the same as the real brand Diet Coke.

Hold on a minute. You thought the post was done, didn’t you? Well, we attempted the experiment again. I had seen movies online of this drink spilling 7 feet in the air. We weren’t doing something right. Since we had already established that the off-brand cola wasn’t any different in results, we bought a bottle of off brand soda and another roll of Mentos, since Storybird and I had finished the other one already.

This time, I borrowed a socket from Grandpa’s tool chest and stacked 5 Mentos in it for easier dropping. We brought the bottle to the end of the dock, and dropped the Mentos in. This time the soda shot the 7 feet I expected.

A few random things we discovered from this experiment:

1. The Mentos react with the carbonation to create the mini-explotion we see, which is why you can’t redo the experiment with the same bottle - the carbonation is gone.
2. The optimal number of Mentos is two. Any more will just drop to the bottom of the bottle.
3. Sockets can be slippery when wet. Make sure to have a tight grip on them when hosing off.
4. Sockets also sink. If done by a lake, make sure to do it in an area where the water is shallow and you can still see the socket glinting in the sun.
5. The stream is very compact. The bottle and about a 8” radius around it will get wet, but not much farther.

If you repeat this, remember: do it in an area you can clean up. Or where nobody cares if you get it a bit sticky. In other words, where the hose can reach.