How to Make Time Bomb Sodas

On Friday afternoon, my Facebook friend Ken Lanious posted this image.



This was a great idea. Could you freeze Mentos into ice cubes and use them to get a geyser-like explosion out of a soda once the ice melted?

I was skeptical, but if it could work, it would have a lot of potential! I decided to try it.

The typical Mentos and Diet Coke fountain depends on that bottleneck at the top of a two-liter soda bottle. For this prank, you'd probably use a regular household drinking glass. I decided I needed to first test if the Mentos and Coke trick would even function in a wide-mouthed drinking vessel.

Yes! We dropped one in and it worked great! Foam exploded up and over the sides of the glass. Not as good as having a bottleneck, but much better than serving a soda which was merely shaken up before it was served.

But could this effect be recreated with a delay timer in the form of an ice cube?

The latest Mentos research indicates that the carbonation-releasing characteristics of Mentos lie in the surface. Either the surface is pitted with millions of pockets where CO2 bubbles can form (nucleation sites), or the dissolving surface creates a ton of tiny particles, which hasten the formation of CO2 bubbles throughout the liquid.

In any case, it seemed important to preserve the hard candy shell as best I could. With that aim, I chilled a tube of mentos, and prepared a jar of very cold water.

I used a few different ice cube trays, including this heart-shaped version from Ikea. The faster the ice solidified, the less effect the water would have on surface of the Mentos. I needed a solid, complete barrier of ice. If the Mentos were hanging out of the ice cube, that part of the exposed candy might ruin the effect after the ice melted.

For one tray of cubes, I let the water begin to crystallize, then broke open the cells and dropped in Mentos.

It was pretty obvious that the Mentos would dissolve a little before the ice cubes were frozen. But would it adversely affect the explosion of carbonation? Time would tell.

To give the surface of the Mentos the best possible chance of staying intact, I employed our Slushy Magic cup, freezing the heck out of some water so it would be very, very close to frozen as soon as I pushed the candy into it.

With my ice cube Mentos safely solidifying in the freezer, I waited.

The next morning I found all the ice cubes were frozen. The color of the Mentos cubes tipped me off that the candy had dissolved a bit in the water before they solidified.

They failed in two ways. While freezing solid, the mentos dissolved a bit, adding sugar to the water surrounding them. This sugar made it even harder for the ice to freeze solid, allowing more time for the Mentos to dissolve.

Only a few of the Mentos cubes froze with a Mentos contained in the center. Most of the candies sunk to the bottom of the tray and escaped the ice completely. In the photo you can see the Mentos left behind after the ice cube was removed.

In the cases where the ice did surround the mints, the power of the Mentos was ruined.

The mint may have increased the bubbles by 50%, but it was hardly enough to notice, and didn't look likely to ever result in an overflowing cup of Coke.

Even where I began with super-cold soft-frozen water from the Slushy Magic, the Mentos candy had dissolved enough to ruin its geyser effect.

Every method had failed. I headed back to the planning stage.

I came up with three new schemes to try.

1. Creating a water-soluble shield with Listerine breath strips.

2. Creating a water-soluble shield with Gummi bears

3. Creating a hollow ice-cube with a dry Mentos candy locked inside.