If you take some scientists' word for it, the biggest agricultural revolution since the domestication of livestock is starting on Monday—in an arts center in London. At a carefully orchestrated media event, Dutch stem cell researcher Mark Post is planning to present the world's first test-tube hamburger. Its patty is made from meat that Post has laboriously grown from bovine stem cells in his lab at an estimated cost of $375,000, just to prove a point: that it is possible to produce meat without slaughtering animals.

Some details of Monday's event are still secret, but Ogilvy, the PR agency hired to handle Posts's publicity, says that the meat will be cooked and then eaten by two volunteers in front of an audience of invited journalists. (It also says that Post, who works at Maastricht University, is not available for interviews until then.) Speculation is rife that the anonymous U.S. billionaire who has bankrolled Post's research project will step forward. And of course, there is the biggest question of all: What will the burger taste like?

Artificial meat research has received lots of media attention, yet so far has produced little anyone could actually taste. Scientists in the field are excited but also apprehensive about the upcoming presentation. "The moment could be historic," says Cor van der Weele, a biophilosopher at Wageningen University in the Netherlands, who has done research on public attitudes toward cultured meat. How people react to the stunt will have huge implications for the future of the research, she says. "If anything unexpected happens, it could backfire."

Henk Haagsman, a veterinary researcher at Utrecht University in the Netherlands who has collaborated with Post, says that he was initially skeptical of the event; now he thinks it may be the right way to grab the public's attention and raise money for research to propel the field forward. However, the spectacle could eclipse the science, he says: "As soon as it turns into a circus for media, people may mix this up with illusionists or magicians."

The idea of culturing meat in the lab is nothing new. In his essay "Fifty Years Hence" published in 1931, Winston Churchill wrote: "We shall escape the absurdity of growing a whole chicken in order to eat the breast or wing, by growing these parts separately under a suitable medium." Modern-day scientists say they know how to fulfill that dream: Stem cells taken from an animal could be cultured and used to grow millions of tons of meat, Post says. In theory, at least, a couple of animals could feed the world.

The benefits could be enormous. According to the Food and Agriculture Organization of the United Nations, global meat consumption may increase from roughly 228 million tons in 2002 to about 465 million tons in 2050. Cultured meat could vastly reduce animal suffering and stop livestock from taking up huge tracts of land and polluting the atmosphere with methane and other greenhouse gases that they emit. In a 2011 study, scientists at the University of Oxford and the University of Amsterdam estimated that cultured meat may need 35% to 60% less energy, occupy 98% less land, and produce 80% to 95% less greenhouse gases than conventional meat. In an interview late last year with ScienceNOW, Post said he realized the potential of lab-grown meat as soon as he heard about it. "The societal impact it could have is way more than any of my biomedical research of the last 25 years.”

There are many hurdles, however. Despite several attempts, scientists have not been able to culture embryonic stem cells from cattle, pork, or chicken. "So far, we have embryonic stem cells from mice, rats, humans, and monkeys—and that's about it," Haagsman says. One way forward would be to use small molecules to turn adult cow cells into so-called induced pluripotent stem cells that could be used instead, he suggests.

There are other problems: Cultured meat is now grown in medium with fetal calf serum, a supplement made from blood collected at slaughterhouses; scientists have yet to find an alternative that doesn't involve dead animals. Guiding stem cells to develop into muscle cells only is also a difficult task. And as soon as scientists grow a piece of meat more than half a millimeter thick, it will need blood vessels to supply cells with oxygen and nutrients and keep them from dying. A lab-grown rib eye or sirloin steak, with its complicated architecture of muscle fibers and fat cells, is still decades away, Haagsman says.

Instead, Post has gone for minced meat, produced not from embryonic stem cells but from myoblasts, stem cells found in adult muscle tissue to replace dead muscle fibers. He has grown tiny pieces of beef muscle in petri dishes; according to a press release, 20,000 of these shreds are needed to build a 5-ounce burger patty.

"This is not the way we would produce it in the future," Haagsman, in part because myoblasts' ability to divide is more limited than that of embryonic stem cells. Post also doesn't have an alternative for fetal calf serum yet, and differentiation into muscle cells needs to become more efficient, Haagsman says. "This is more of a demonstration project."

Post isn't the only researcher hoping to relocate meat production from the farm to the lab. Gabor Forgacs, a researcher at the University of Missouri, aims to use 3D printing technology to build bigger pieces of meat from muscle cells. Modern Meadows, the company he founded, announced last year that it had received $350,000 from the foundation of PayPal co-founder Peter Thiel.

But in general the field has suffered from "an extreme lack of funding so far," says Van der Weele—which could change after the London event. At the same time, "you could get a general atmosphere that this is a kind of Frankenstein food," she says, adding that much will depend on the words and images the media use to portray the event. To Van der Weele, Monday's burger tasting will not be just an interesting culinary experiment but a psychological one as well.

Kai Kupferschmidt will be live-tweeting from the event. To keep tabs on the latest on artificial meat, follow Kai at @kakape.

A live video feed of the event will be available at www.culturedbeef.net.