BERKELEY, Calif. — Rabbi Gavriel Price has thousands of years of Jewish religious law to draw on when he is on the job, determining whether a new food item can get a kosher certification from his organization, the Orthodox Union.
But all the rules about meat and milk, and the prohibitions on eating pork and sciatic nerves, are of limited use for Rabbi Price's latest assignment.
The rabbi is in charge of figuring out how the Orthodox Union, the largest kosher certifying organization in the world, should deal with what is known as clean meat — meat that is grown in laboratories from animal cells. This brings him in touch with a possibility for Jewish cuisine that had previously seemed impossible: kosher bacon.
Clean meat is still not available in stores, but start-ups working on it say it could be by next year. When it is, they want a kosher stamp on their product, which indicates it adheres to quality and preparation standards and follows a set of biblical laws. That brought Rabbi Price, a tall, lanky father of eight, to Berkeley recently, to meet with companies in the business.
Clean meat, also known by names like cell-based agriculture, begins with cells taken from an animal, often stem cells that are primed to grow. Once these cells are isolated, they are put into a solution that mimics blood and encourages the cells to replicate.
This process is very new. The first hamburger produced in a lab was served with great fanfare in 2013 and cost $325,000. But the number of companies competing to create the first commercially available product is growing rapidly.
Rabbi Price's investigation touches on questions that anyone might have when confronted with clean meat. What exactly is it? And should we want to eat it someday?
His first stop was a lab operated by Mission Barns, a start-up with six employees and millions of dollars in funding. It is growing duck, chicken and pig meat in clear flasks, lined up inside temperature-controlled incubators.
He looked through a microscope at a dish of long, pointy duck cells and peppered the scientists with basic questions about where the cells had come from, and what was in the red liquid that was helping the cells to replicate and grow.
"I'd like to spend more time, because I think it's an important process to understand in a deep way, and there's no precedent for it really," Rabbi Price said after the tour.
The issue he is addressing is much more complicated than the kosher designation of plant-based meat substitutes already available in grocery stores.
Perhaps the best known company of its kind, Impossible Foods, has created a burger that is made from all-vegetarian ingredients but tastes more like meat thanks to a chemical process involving yeast and soy. Like most vegetarian foods, these burgers have received a kosher stamp.
Mission Barns, the start-up in Berkeley, is focused on creating animal fat, where much of the distinctive flavor of meat resides. It recently mixed the fat with other ingredients to create duck sausages that it served to investors and employees. Creating more structured meat products, like a duck breast or a steak, is expected to take much longer.
Environmentalists and animal activists are proponents of the technology because it could produce the flavor of hamburgers and sausages without the greenhouse gases and animal suffering of the factory farming system.
Jewish authorities hope the process will make kosher meat more affordable and reliable.
"I'm extremely excited about it," said Rabbi Menachem Genack, who leads the kosher certifying division of the Orthodox Union. "The impact for us will be very profound, in terms of the economics of kosher meat."
There are polls that show that many Americans are turned off by the prospect of lab-grown meat. And the technology has already generated questions far beyond the Jewish community.
The United States Cattlemen's Association requested this year that American authorities allow the meat label only on products that come from slaughtered animals. While large meat companies have pushed back against the cattle ranchers, in part because they are developing their own clean meat products, it is unclear if regulators will handle lab-grown meat with the same rules they use for traditional meat.
Jewish authorities have been studying this because several synthetic meat start-ups are based in Israel.
A number of Israeli rabbis told one start-up, SuperMeat, that previous rulings in religious law might allow clean meat to be categorized as pareve, a religious label that is applied to things that are kosher but not derived from animals.
A pareve label would mean that observant Jews could eat it with dairy products, like cheese, which cannot be eaten with traditional meat. In other words, a kosher cheeseburger might be possible.
Rabbi Genack, Rabbi Price's boss at the Orthodox Union, initially thought clean meat could be pareve, based on his belief that clean meat was created from an animal's genetic code. But because the process involves an animal cell, replicating itself millions of times, he now believes the product should be thought of as meat.
When Rabbi Price visited the Mission Barns labs, he asked questions specific to kosher certification. He wanted to be sure, for instance, that the pork cells growing in one incubator never come into contact with the duck cells in the incubator next to it, and that the centrifuge where the meat cells are processed is cleaned thoroughly between processing.
He also wanted to know if the cells in the flasks changed as they replicated, to be sure that they do not morph into something that no longer resembles the original animal cells.
"The identity of a given cell, and ensuring that its identity is preserved and verifiable, would be crucial to our being able to certify a product," the rabbi said.
The day after his visit to Mission Barns, Rabbi Price attended a conference held by the Good Food Institute, an organization that is encouraging the move away from animal meat.
He dived into long conversations with people working for the food start-ups. They discussed topics as diverse as the kosher status of gelatin, the religious rulings of venerated medieval rabbis and the ingredients of the solution that encourages lab-grown meat to grow.
"Does that cell need to consume all kosher ingredients for it to be kosher?" the rabbi was asked by Aryé Elfenbein, the founder of Wild Type, a start-up in San Francisco that is focused on lab-grown salmon.
The rabbi explained that just as kosher cows can eat non-kosher insects, he is working from the assumption that the growth solution will not have to be certified as kosher as long as it is cleaned from the surface of the final cells.
Many of the questions came back to the original cells that go into the solution. The rabbi said those cells would have to be kosher, from an animal that was properly slaughtered and not scraped off a live animal. (There is a Jewish law against eating live animals.)
This was not well received by some of the clean meat companies, which want to produce something that does not involve killing any animals.
The liveliest conversation grew out of research that is looking into whether clean meat might be derived from cells in animal saliva or hair.
The rabbi said those substances are not meat, so they might be used to produce clean meat that would not be categorized as meat by Jewish law.
Eitan Fischer, the chief executive of Mission Barns, said he was hopeful that through some creative chemistry, his company could grow pork that would get a kosher designation.
"If we can create kosher bacon one day, as weird as that sounds, I think there is going to be so much excitement around that," he said.
Rabbi Price was cautious. In addition to the kosher laws, there are Jewish rules that warn against doing anything that would make people look as though they were violating the rules.
The rabbi added that there are religious texts that discuss the possibility of kosher pigs, once the Jewish messiah arrives and ushers in an age of universal peace. But he is skeptical.
"I'm looking around, and I don't see much evidence we are in messianic times," he said.