High Steaks: The Kashrus of Lab-Grown Meat

Talking with Rabbi Menachem Genack, CEO, OU Kosher

Jewish Action: What exactly is lab-grown meat?

Rabbi Menachem Genack: Lab-grown meat, also known as synthetic or clean meat, is essentially “meat” grown in a lab from animal cells, resulting in a product genetically identical to conventional meat. Clean meat companies, still in the start-up stage, are working on developing this technology.

JA: Is clean meat kosher?

RG: It has the potential to be kosher—but it depends on a few factors. 

Firstly, if the animal cells are derived from a non-kosher animal, the end product will be non-kosher as well. This is based on the principle of yotzei min hatamei tamei, anything derived from something that is non-kosher is non-kosher. Thus, the OU’s position is that clean bacon is not kosher, since the original cells of the pig serve as the source. 

Secondly, some clean-meat companies prefer to extract cells from live animals. The OU’s position is that this presents a problem of eiver min hachai (eating a limb torn off a live animal). Therefore, a kosher animal would need to be slaughtered before its cells could be extracted for the purpose of growing them in a lab. 

Finally, the shechitah would need to take place under reliable kosher supervision. 

To summarize: in order for clean meat to be kosher, the original cells must come from a kosher animal that was slaughtered under reliable kosher supervision.  

It is worth noting that given the sensitivity of creating kosher meat in this manner, it will undoubtedly require close monitoring and a high level of kosher supervision. 

JA: Does lab-grown meat have the status of meat or pareve?

RG: On the face of it, one would assume such meat would be pareve. Modern science is able to reconstruct the host environment, allowing the stem cell to grow and multiply. Thus, most of the growth takes place outside of the animal, which perhaps suffices to render the product pareve. Furthermore, the original biopsy is miniscule compared to the final product. Additionally, just because something is derived from meat doesn’t necessarily give it the status of meat. The most dramatic example of this is, of course, milk: milk comes from an animal, but it obviously does not have the status of meat. 

We turned to many posekim within the OU orbit with these questions. Some rabbinic authorities ruled that clean meat is pareve, while others determined it to be fleishig. 

Rav Asher Weiss, a leading dayan in Israel and halachic advisor for OU Kosher, maintains that lab-grown meat is halachically identical to meat. In his view, if it looks like meat and has all the characteristics of meat, it is meat. 

Rav Hershel Schachter, rosh yeshivah at Yeshiva University and halachic advisor for OU Kosher, maintains that lab-grown meat is not meat on a Biblical level (deOraisa), but it does have the status of meat on a rabbinic level. In other words, lab-grown meat has the same status as poultry. From a Biblical perspective, it is not forbidden to eat or cook poultry with milk. The rabbis forbade it due to poultry’s similarity to meat, in order to avoid confusion and the potential violation of a Biblical prohibition. So too, due to its similarity to conventional meat, lab-grown meat is, in Rav Schachter’s view, considered meat on a rabbinic level and is therefore subject to the same rabbinic prohibitions as poultry.

In the past five years, billions of dollars have been spent on developing the 100-plus startups in the [lab-grown meat] industry. —Chloe Sorvino, “Everything You Need to Know about Lab-Grown Meat Now That It’s Here,” Forbes, June 27, 2023

After much consultation with posekim, the OU is taking a stringent position, and regards lab-grown meat as meat on a Biblical level. It should be noted, however, that even according to those rabbinic authorities who regard lab-grown meat as pareve, such meat would need to be treated carefully because of the halachos of maris ayin, that is, the prohibition against doing something that may cause another to think that one violated halachah. This is similar to the halachah [Shulchan Aruch, siman 87] stating that one who wants to cook meat with almond milk should place almonds or almond milk on the table to clearly indicate that he is not cooking or eating meat and milk together. 

Incidentally, the issue of maris ayin also applies to plant-based burgers, such as the Impossible Burger. One eating an Impossible Burger with cheese should, for example, place the Impossible Burger package on the table. 

There is a machlokes as to whether the issue of maris ayin applies even when one is alone in his home. 

JA: Is there a way of producing kosher lab-grown meat without requiring slaughter?

RG: SuperMeat, a leading cultivated meat company based in Israel, is developing chicken meat using an entirely different method—extracting stem cells of fertilized chicken eggs. If the cells are drawn from the egg before blood spots develop, the cells and the resultant meat are kosher. No shechitah is necessary in this case, because the cells come from eggs, not animals. 

Currently, lab-grown meat costs thousands if not hundreds of thousands per ounce to produce. —Chloe Sorvino, “Everything You Need to Know about Lab-Grown Meat Now That It’s Here,” Forbes, June 27, 2023

After a series of in-depth halachic discussions and scientific reviews, the OU determined that SuperMeat’s chicken cell line adheres to kosher meat mehadrin standards. These reviews focused on avian embryogenesis and stem cells, including observing the drawing of embryonic stem cells from a fertilized chicken egg prior to the appearance of blood spots. 

The question then becomes: What is the status of chicken meat derived from the stem cells of fertilized chicken eggs—is it pareve or fleishig? The OU has yet to make a determination. (Interestingly, the CEO of SuperMeat told me that he would prefer that his product be considered meat, not for halachic reasons but because of marketing considerations—the company wants its products to be viewed by consumers as real meat.)

JA: Why all the excitement surrounding lab-grown meat? 

RG: Clean meat is being hailed as a humane and climate-friendly solution to traditional animal agriculture. There are those who maintain that livestock production plays a huge role in contributing to the world’s greenhouse gases annually. The carbon footprint, they contend, would be greatly diminished if we move away from slaughtering cattle. There is also a tremendous need for new sources of protein. As the world population grows, and companies and governments search for new sources of protein, clean meat is increasingly being viewed as a way to stabilize a source of protein for future generations. 

JA: Does lab-grown meat offer any particular benefits to the kosher consumer?

RG: In traditional meat production, the kosher market can only make use of about 20 percent of meat—only about 40 percent of animals are glatt (i.e., free of adhesions in the lungs that may make them treif), and of the glatt animals, in the US we generally only use about half of the animal because the Ashkenazi custom is not to use the hindquarters at all since they contain the forbidden fats and sciatic nerve (cheilev and gid hanasheh). Lab-grown meat would not have these concerns, and therefore 100 percent of the meat would be kosher. Ultimately this could significantly lower the cost of kosher meat. 

JA: Is there any precedent in the classical halachic literature addressing this phenomenon?

RG: While unsurprisingly there are no explicit sources addressing this new phenomenon, an interesting possible parallel is discussed in the Talmud: meat produced by a miracle. In Sanhedrin 59b, the Gemara relates the following incident: 

As Rabbi Shimon ben Chalafta was walking along the way, he encountered lions that were roaring at him. He said: “The young lions roar after their prey [and seek their food from G-d]” (Psalms 104:21). Two thighs [of an animal] descended [from heaven] for him. The lions ate one [of the thighs] and left one. He took it and entered the study hall, and inquired about it: “Is this a kosher item or a non-kosher item?” The Sages said to him: “Certainly it is kosher, as a non-kosher item does not descend from Heaven.”

Rav Asher Weiss cites this as support for his view that something which appears to be meat is considered meat according to halachah. He points out that the only question in the Gemara is whether the meat is kosher. No one seems to have entertained the possibility that because it did not come from an animal, it is not meat at all. This must be because as long as it is indistinguishable from meat, even if it “descended from Heaven,” it is considered meat. 

JA: When do you think synthetic meat will be available to the kosher consumer?

RG: Bringing lab-grown meat to market may take a number of years; government approval is required, and it must become financially feasible. But this technology undoubtedly has tremendous potential to change the way we eat. As we are the leading kosher agency in the world, companies are reaching out to us; they want to know how we would view such a product halachically. We believe lab-grown meat will be available commercially in the kosher world within a few years. 

Rabbi Menachem Genack has served as CEO, OU Kosher, since 1980. Special thanks to Rabbi Gavriel Price, rabbinic coordinator, OU Kosher, for his assistance in preparing this article. 

This article was featured in the Summer 2024 issue of Jewish Action.
We'd like to hear what you think about this article. Post a comment or email us at ja@ou.org.