“When I pruned the tree it would be shaken in the process, and the mush would slip out of the bottom of the ‘ghost apple,'” Andrew told. “Most apples just fell off, ice and all. But quite a few would leave a cool ‘ghost apple’ behind.”

“I guess it was just cold enough that the ice covering the apple hadn’t melted yet, but it was warm enough that the apple inside turned to complete mush (apples have a lower freezing point than water).”

“I’m sure you could find them at any orchard on the Ridge (near Sparta, MI), or at least any that still had a few unpicked apples hanging on the trees,” he added. ‘Jonagold’ is one of my favorite apple varieties, but we’ll call these “Jonaghosts.'”

According to Andrew, not a lot of fruits and veggies are capable of pulling off such a stunt. “You could only find them on other fruits and vegetables if they remained unharvested and persisted into the winter. Most crops do not.”

William Shoemaker, a retired fruit and vegetable horticulturist from the University of Illinois, told Forbes that those apples, leftover from harvest, just went through a week of “exceptionally cold weather” due to the polar vortex. “Besides being somewhat mummified, they could also be rotten,” he said. “[If so,] they maintain their form, but their substance gets closer to applesauce.”

When their temperature drops to around -18°C (0°F), their structure collapses, and a few could “spew their rotten contents successfully.” Although people might wonder why the apples didn’t freeze solid, Shoemaker reminded that the apple has a significant acid content, so it has to get extremely cold before it freezes as well.