Why won’t this ice cream sandwich melt?

What's really in those ice cream sandwiches? (iStock)

Eating ice cream is the summer heat is one of life's great feats, but is it really ice cream if it doesn’t melt?

Christie Watson of Cincinnati had been treating her kids to ice cream sandwiches from Walmart but one morning she noticed an uneaten sandwich left outside had barely melted overnight in the 80 degree weather.

"I thought that's quite weird," Watson told local station WCPO 9. "So I looked at the box, and it doesn't say artificial ice cream. It says ice cream."

Perplexed, she shared her story and the station decided to conduct a little ice cream experiment.

The station set out three popular ice cream products—a Walmart Great Value Sandwich bar, a Klondike sandwich, and a pint of Haagen Dazs-- in the sun and waited for 30 minutes.

The results: after half an hour, the Haagan Dazs had turned into soupy goo, the Klondike sandwich had melted a little but the Walmart sandwich, though condensed, retained its solid state and looked like a sandwich just out of the fridge.

So why wasn’t the ice cream melting?

WCPO 9 contacted Walmart which released the following statement to the news organization:

Ice cream melts based on the ingredients including cream. Ice cream with more cream will generally melt at a slower rate, which is the case with our Great Value ice cream sandwiches.

It turns out ingredients play a huge role in the melt factor of certain frozen treats.

Walmart and Klondike ice cream sandwiches contain corn syrup, guar gum, and cellulose gum --"stabilizers" which help extend ice cream's shelf life and the melting process.  Haagan Dazs contains just five ingredients-- cream, milk, sugar, and eggs, and vanilla—with syrups or gum of any type mentioned. It does, however, have a higher fat content than the bars that use such ingredients and is generally more expensive.