Last January, during a meet-and-greet of American food professionals and Israeli tech entrepreneurs at the headquarters of Start-Up Nation Central in Tel Aviv, I met Didier Toubia, co-founder and CEO of Aleph Farms. Toubia, a bespectacled fellow wearing a yarmulke, spoke with a French accent, lending himself an air of culinary credibility—a good thing, seeing as he was there to talk about beef.Toubia didn’t discuss grass-fed or wagyu or dry-aged meat. His startup raises what he called “hydroponic meat”—that is, meat that is grown in a lab from stem cells and nourished by a substance that mimics bovine fetal serum, which then develops into tissue that is chemically identical to meat. “We reproduce the same environment inside a bioreactor as what is inside a cow,” said Toubia.And no cows die in the making of this steak.According to Toubia, the animal isn’t harmed in the least by the stem-cell extraction. And while earlier examples of clean meat have been created using real bovine fetal serum, which is harvested from dead pregnant cows, Aleph Farms—part of the Kitchen Food Tech Hub, a collection of “food industry disrupters” founded by Israel’s Strauss Group—uses a plant- and yeast-based alternative.So far, Aleph Farms has succeeded in generating steaks about the size and thickness of a credit card. There were no samples to be tasted, but the promise of what the innovation could bring transcends something as pedestrian as eating. Toubia foresees lab-grown meat as the potential answer to many of the world’s great problems—poor animal welfare, environmental damage caused by industrial farming, and the overuse of antibiotics in livestock, the cause of superbugs and antimicrobial resistance. It can even help reduce pathogens and foodborne illnesses in the food system and alleviate our climate crisis.And, Toubia said, Aleph Farms will offer a kosher product.How can meat be kosher if it’s never been slaughtered?As rabbis and scholars have closely followed recent developments in a field known by many names—clean meat, lab-grown meat, cultured meat, cellular agriculture—that’s the question they’re trying to answer.*It all started in 2013 with the $325,000 “cultured meat” burger created by Dr. Mark Post of the University of Maastricht in the Netherlands, which ignited a sense of possibility of slaughterless meat, and raised the question of what cultured meat is exactly from a Halakhic point of view. Those earlier speculations were of a less informed and more sensationalistic nature, with some rabbis postulating that meat created in a lab is not meat at all. What followed was the possibility that it could be pareve, making a cultured cheeseburger or even lab-grown pork a possible snack for future Jews.Today, with more companies racing to make cultured meat for the masses, and some serious investment dollars behind them, a world with lab meat is looking more realistic than ever before. Aleph Farms just announced in May that it has completed a financing round of $11.65 million, including investments from the industrial farming monolith Cargill. Tyson, meanwhile, invested $2.2 million in the Jerusalem-based startup Future Meat, a company whose goal is to get affordable clean meat on the market by 2020. According to a recent tally, among the few dozen or so companies that are developing lab seafood, poultry, and beef, the industry leaders are based in Israel. Dan Shapiro, author of the book Clean Meat: How Growing Meat Without Animals Will Revolutionize Dinner and the World, called Israel “a Mecca for the cultured meat world.”For Toubia, who has been working closely with rabbis as he develops his product to understand its halakhic implications, it is a priority to make the meat accessible to everyone, including Muslims, Hindus, vegetarians, and observant Jews like himself.Seeing as there is no clean meat product on the market yet, pronouncements of kashrut are still hypothetical, and in many cases premature. But that hasn’t prevented rabbis from familiarizing themselves with the new technology, and rigorously mulling over how ancient Jewish laws apply.Rabbi Ari Zivotofsky, a professor of neuroscience, is a trained shochet, and specializes in the kashrut of exotic animals and birds. He also teaches a masters program at Bar Ilan University on the interface between emerging science and Halakha, and has been consulting Aleph Farms as the company attempts to navigate the laws of kashrut. It … is confusing. “It is difficult to find sources in the Talmud to serve as precedent for these questions,” said Zivotofsky. “But the basic questions are out there.”First, you need starter cells to grow the muscle tissue in the lab. Slicing a piece of meat off of a live animal is strictly prohibited in Jewish law. And while it might not have caused the animal pain to remove a very small amount of tissue, some interpretations of Halakha would determine that meat derived from the cells of a living animal is non-kosher. So there’s that.From this question springs a possible loophole. “What if I take starter cells from a non-edible part of an animal and I am able to trick those cells into producing muscle?” asked Zivotofsky, referring to practices of companies like San Francisco-based Just, which grows meat from chicken feathers, skipping over the live animal conundrum altogether.And if you are taking stem cells from a live animal? Since the stem cells extracted from the tissue sample are so tiny as to be microscopic, ponders Zivotofsky, are they still subject to the laws of kashrut? In a comprehensive article called “Stem Cell Burgers,” J. David Bleich, an expert in bioethics and a professor at the Cardozo School of Law, cites the possibility that, because the stem cells are unseeable, they could escape Halakhic scrutiny, much in the same way that tiny organisms living in water do not make water unkosher, because they are invisible. When used in the service of generating clean meat, can stem cells still be considered too small to be subject to Halakhic standards? If yes, Bleich says, then even a stem cell derived from a nonkosher animal might be perceived as kosher (though he ultimately rejects this notion).Then, says Zivotofsky, one must ask: “Where do the cells grow? They need nutrition or some food, and one of the best sources turns out to be serum.” Or, more precisely, fetal bovine serum, the clear liquid that is extracted from the blood of cow fetuses, which has been the prevalent nourishment relied on by clean meat to grow their tissue. (Though, according to Toubia, the major players are developing alternatives.) For some observant Jews, the substance may be problematic because it’s derived from blood, which itself is considered unkosher. This raises the question of whether or not fetal bovine serum can be used to nourish the stem cells in the creation of kosher clean meat.The Orthodox Union, the leading kosher supervisory agency, has weighed in on the matter, and would permit the use of fetal bovine serum in the creation of clean meat. With guidance from the Halakhic authority Rabbi Asher Weiss, the O.U. has reached a preliminary conclusion that in order for clean meat to be deemed kosher, the starter cells must be derived from an animal that was kosher-slaughtered. However, according to Weiss’ interpretation, fetal blood serum is permissible, because there is no blood left in the serum once it is used to grow the stem cells.Menachem Genack, CEO of O.U. Kosher, has been engaged in such questions for a couple of years now. His initial position was that the lab meat may be pareve, since, in his earlier opinion, he was not convinced that it was really meat. But that has changed. “It is just a matter of understanding the technology better,” said Genack. “I thought that they have a sample DNA and that was just a template for producing the other cells, but that is not the case. They take the initial cells and they continue to divide as they would in the body.” In other words, it is meat because it has the cellular construction of meat. “It has all the qualities of meat,” he said. “If it looks like a duck, walks like a duck, and talks like a duck, it’s a duck.”There are some people in the O.U. who still believe that meat is pareve if it is grown, rather than born. What would that mean practically for kosher labeling? “Fundamentally it would be considered pareve, but it looks like meat, so you have to identify it in some way,” said Genack. “If you eat that meat and want to eat dairy right after, you’d have to indicate that it is artificial clean meat, a practical implementation. Even almond milk, you have to designate it in some way so you don’t think it’s milk.”But the official stance of the O.U. is that artificial meat is indeed meat, and will be subject to kosher laws accordingly. “Because there are differing opinions about it, we will take the more stringent opinion that it will be considered meat,” said Genack.Genack sees a great advantage for the kosher market if a clean meat were to be produced that met the O.U.’s standards. “When we slaughter animals for kosher consumption, 60% of the animal is deemed to be unkosher,” he said, and only 20% of what is kosher is usable. If the promise of kosher clean meat were realized, in Genack’s estimation, it would all be 100% glatt kosher. Plus, he, like many others, sees the potential for positive environmental impact: “Globally, if it succeeds on a mass level, it has enormous value, because the carbon footprint in the United States of methane and carbon dioxide from cattle is greater than that of cars in America,” he said. “It can have an enormously beneficial effect in terms of environment and climate change.”However, there are skeptics who doubt that clean meat, kosher or not, will be the silver bullet that so many are seeking. “We have had a relationship with animals for thousands of years that is worthwhile and we should work on improving that relationship,” said Yadidya Greenberg, founder of the Healthy Kosher Foods Project, a soon-to-open nonprofit focused on improving health and well-being of kosher consumers and the animals used in the production of kosher foods. “Lab-grown meat, I feel, is the pinnacle of factory farming,” he said. “They are already trying to take animals out of the equation as much as possible. Tyson and other large meat companies are very interested in clean meat—they are all investing in it. They’re trying to present lab-grown meat as something that will save the world, and I don’t buy it for a second. If something that comes out of it that is transparent and it tastes good and is healthy and safe and can replace factory farmed products on the shelf, then I am open to it. There is mostly hype, but there is nothing really there yet.”*On a screen behind Toubia at last January’s gathering, a chef in a gleaming modern kitchen seared a comically small piece of clean meat, no bigger than the tiniest minute steak, in a promotional video for the brand. Toubia told me that while other clean-meat companies are focusing on making lab-grown hamburgers, what sets his company apart is the culinary ambition of the product they are developing—an actual cut of meat, without fillers, that is of gastronomic value and will even taste good. The cut he is looking to debut with when Aleph Farms eventually introduces its meat to the marketplace is a replica of filet mignon, though that day is still far off. Of the growing number of startups in the clean-meat race, none has released a cultured meat product on the market. So far, the dream of kosher steaks, seafood, and poultry saving the world remains to be realized.***Like this article? Sign up for our Daily Digest to get Tablet magazine’s new content in your inbox each morning.