Jess Bowie can still remember her first vegetarian lapse. She was 9 years old.

“It was my brother’s birthday party and my parents had laid out all this food for his friends,” she explained. “I snuck into the room without anybody seeing me, and I ate the chicken nuggets.”

The guilt stayed with her for years, but she confesses that the chicken tasted great. “Meat is objectively delicious. I don’t understand vegetarians who say they don’t like the taste,” she told me. “I can’t wait to try test-tube meat.”

Artificially grown meat, created in a lab without directly harming any animals, is expected to be on sale within the next 20 years. But the debate among vegetarians and vegans about the freaky frankenburgers was kicked off in earnest this week as the first proto-type “in vitro” hamburger was eaten in London on Monday.

Bowie, 29, who lives in Brixton, South London, is one of millions of non-meat eaters standing at a crossroads: if no animals were hurt, would you eat this “meat”?

The debate is raging on vegetarian forums and on Reddit. “I hope that lab meat someday catches on and can help end animal suffering,” wrote one user by the name of RUTHWHIPKEY. “However, I would probably gag.” Another user, calling himself Leo 99, would have no such qualms: “I’m a vegetarian because of cruelty of factory farming and because of the terrible environmental impact it causes, so yes, I would eat the meat.”

For many vegans and vegetarians, the precise method of lab-meat production is crucial in making a decision. The meat eaten Monday in London came from cells that were harmlessly extracted from living cows. Those cells, however, were then grown using fetal bovine serum, an unappetizing by-product of the slaughter of pregnant cattle.

“Everyone in the field acknowledges this as a problem,” says Dr. Neil Stephens of the use of the serum. “It’s not in any way animal friendly, it’s not cheap and it’s not environmentally friendly. It currently undermines a lot of the arguments that people put forward in support of in vitro meat.” Stephens, a sociologist at Cardiff University, has spent years studying the development of “cultured” meat. “There is a significant and long-lasting debate about where you get the cells and how you treat them,” he said.

The Vegetarian Society also told me the jury was still out. “We can’t make a decision because we don’t know enough about the final product,” said Liz O’Neil, a spokeswoman. “They are welcome to apply for a Vegetarian Society approved trademark, then we would rule if it was vegetarian.”

Others are less ambivalent. Julian Savulescu, the director of the Oxford Uehiro Centre for Ethics, said the details were irrelevant and urged vegetarians to embrace the biological breakthrough. “People who are vegetarian for moral reasons—the environment, the treatment of animals—have a moral obligation to eat this meat,” he told the BBC. “They need to do this because it will contribute to an ethical alternative to conventional meat.”

Theoretical ethics aside, plenty of non-meat eaters find the idea repulsive. Laura Brewin, 32, a call center manager from Cardiff, told me she couldn’t stomach the idea: “At least it’s acknowledging that animals suffer, and admitting we can’t keep killing animals for their flesh, but this is ‘meat’ derived from the stem cells of a cow, grown in a lab with lab-grown fat added. I wouldn’t eat that!”

Surprisingly, the biggest advocate of growing meat artificially is also against vegetarians switching over. Speaking at the presentation of his research yesterday, Dr. Mark Post said: “Vegetarians should remain vegetarian. That’s even better for the environment.”

It might be better for the environment, but that’s not going to help with Jess Bowie’s cravings. “Lots of vegetarians have got a carnivorous streak,” she said. “We are a family of vegetarians, but this in vitro meat means that could be about to change.”