Physicists Have Finally Figured out Why Grapes Explode into Flames in the Microwave

Photo Credit: Hamza Khattak

In “weird science” news, scientists have finally figured out why grapes explode into flames in the microwave.

Most folks have never had a reason to microwave a grape, because why would you. But if you did cut a grape into half and plop it into the microwave, it would spark and begin to spit out bright plasma.  It’s a strange, mysterious phenomenon, and sciences have finally figured out why it happens.

Photo Credit: Hamza Khattak

Physicists at Concordia University experimented with microwaving a variety of grapes, as well as other round grape-like objects like hydrogel bead, cherry tomatoes, and water-filled quail eggs. They proved that any of these objects behave the same way in the microwave. The grapes don’t even have to be cut for it to work – two peeled grapes side-by-side will also ignite.

Several years and 12 dead microwaves later, the team settled on a theory. Grapes are made mostly of water, which reduces the wavelengths of microwaves. The microwaves become so small that they’re smaller than the grape.

Photo Credit: Hamza Khattak

“Microwaves can get trapped inside the grape,” study author Pablo Bianucci explained. And when two peeled grapes are side-by-side, the waves “hop” from one to the other.

“This hopping results in a very strong electromagnetic field in between the grapes,” he said. That field ionizes the sodium and potassium ions in the grapes… and boom – fireworks.