Some AirPods Pro owners report an unusual smell emanating from the plastic and rubber casings of Apple’s hot new earbuds. Of all things, they say they detect a whiff of … blueberries.

One expert tells Cult of Mac the aroma could be deliberate, or simply a result of chemical compounds in the plastics.

“My AirPodPro’s smell like…Blueberries,” wrote enduro0125. “Or maybe Fruity Pebbles.”

Afterward, others confirmed smelling a similar scent on that forum, as well as on Reddit’s Apple forum.

“Wait, so it’s not just me?” wrote ZoroastrianChemist. “These things legit have a fruity smell, right?”

“Mine smell like that too!” commented kockgunner. “When I first unboxed them they smelled like a strange cheese.”

“I just smelled mine and they do smell like blueberries,” said Clockworkz. “A cheap blueberry type smell, but still.”

Some seven weeks since the first report, Reddit contributor MrChees3 wrote, “I always thought it was definitely a rubbery silicone smell, but going into it with the expectation of blueberries, I can definitely see how it smells like that.”

Expert: It’s all in the plastics

Some contributors speculated that the blueberry smell could come from esters, chemical compounds used in the plastics manufacturing process. One expert agrees.

David Gossman, a chemical investigator with Gossman Forensics in Maquoketa, Iowa, told Cult of Mac certain forms of ester are also used as fragrances and found in essential oils and pheromones.

“Esters are commonly associated with fruity odors,” Gossman said. “Pineapple, banana, blueberries. Those are very common fruit esters.”

Aldehydes, another type of chemical used in plastics, also emit fruit odors, Gossman said.

“The structure of these chemicals is what triggers the nerves in your nose and your mouth for those odors,” he said. “Many flavors actually come from odors.”

Blueberry AirPod Pros: Accidental or deliberate?

The reported blueberry fragrance of AirPods Pro is very similar to that of a “new car smell” — or as Gossman called it, “off-gassing.”

“In simple terms, plastics have molecules that, when they are new, they off-gas smells or odors,” he said.

While many plastics naturally emit smells, manufacturers often add other chemicals to deliberately create a positive odor, Gossman said.

“While I can’t say Apple did this on purpose, I can say many manufacturers do add additional plastic compounds to make their products smell good,” he said.

The various blueberry reports may offer some interesting discussions on the smell of new products, but some people have been trying to bring the conversation back to reality.

On Reddit, Jayvapezz reminded users, “The AirPods are supposed to go in your ears.”