Cannabis ice cream: Ben and Jerry founders fly the idea but will owners Unilever bite?

Greenfield said, "Ben and I have had previous experiences with . . . substances," he said. "I think legalising marijuana is a wonderful thing."

The notion caught fire, with web sites across America picking up the idea in the past week .

Adweek wondered, “just how likely it was that we would be seeing a Ben & Jerry's flavor like Reefer Rum or Cheeba Cherry in the freezer case anytime soon?”

It's not up to the two founders. Ben and Jerry’s is now owned by the British-Dutch giant Unilever, who bought the brand in 1980. A question The Drum to the British PR team had brought no response as the week ended.

Yet it might not be out of the question, either.

"It wouldn't be out of line with their brand," said Jennifer DeFalco, creative director and co-founder of Denver-based Cannabrand, a marijuana-focused branding and marketing firm. "They already have flavours like Half Baked and Satisfy My Bowl."

Ben & Jerry US spokesperson Kelly Mohr told Adweek that "Ben & Jerry's hasn't given serious consideration to the possibility of cannabis-infused ice cream," but added, "Perhaps it's high time."

Some 24 million Americans say they used pot on a semi-regular basis, and a 2013 survey conducted by YouGov found that 26 percent of respondents said they'd consider buying and trying it if it were legal in the state they live in. What's more, edibles are an increasingly popular way to consume the herb.

A report on cannabis consumption issued last year by the Colorado Department of Revenue found " a slow but steady shift away from the traditional method of consuming marijuana—smoking it—to new delivery methods."

However, although Ben and Jerry founded Ben & Jerry's, the pair inasist they have no say in what the brand does any more.

They sold their interest to Unilever as part of a $326m deal.

Greenfield said a cannabis flavour, "is not my decision. If it were my decision I'd be doing it. But fortunately we have wiser heads at the company that figure those things out. We actually don't run anything."

What's more, if Unilever did decide to get into cannabis, it would have to accept the kind of restrictions that few international consumer-packaged-goods brands want to deal with, said Adweek.

The U.S. market would be restricted to states where recreational pot use is legal. And so far, that's only Colorado, Washington, Oregon and Alaska.

"What's more, grocery stores couldn't stock it, only licensed dispensaries, and Unilever would have to manufacture each state's ice-cream batch within that state, since it's illegal to transport cannabis across state borders," said the magazine.

Finally, there's the significant problem of a mainstream brand turning off more conservative consumers by offering a product that many still see as an illegal drug.

"I'm not so sure that Unilever can take that risk," DeFalco said. "It might not be the right brand." Still, she added, "It's a huge market, so it could make sense."

It could. After all, Ben & Jerry's corporate website does say its mission is to make the finest quality ice cream "and euphoric concoctions."