Lab Grown Meat: Part 3

The first installment was a broad overview of the technology and process of growing meat in a lab. In the previous installment, we discussed the provenance of stem cells from kosher or non-kosher animals and the requirement of salting. In this final installment of our series on cultured meat, we will address the last three remaining points.

1. Culture medium: What are the kashrus requirements for the culture medium used to nourish the stem cells? Can serum (also called albumin), which is derived from animal sources, be utilized?
2. Meat status: Is cultured meat considered fleishig (meat) or pareve (neutral) according to Halacha?
3. Ma’aras Ayin: How can we address the concern of ma’aras ayin, which dictates that foods must not be prepared in a way that could be misleading or appear to be something they are not, in the case of lab-grown meat that closely resembles traditional meat?

Culture Medium:
The culture medium, in which the stem cells are nourished, is typically derived from a combination of natural and synthetic sources. One crucial component is serum, the clear liquid portion of blood that remains after blood cells and clotting proteins have been removed. Since blood is not kosher, does this mean that serum cannot be used?

This is indeed a complex question and one that is still under deliberation by Poskim.

Two arguments have been presented to justify the use of serum¹:
1. Since the blood cells have been removed, the clear liquid that remains does not retain the Halachic status of blood.
2. The cells feed on the serum to proliferate, which mirrors the natural process in a living animal, where cells derive nutrients from blood. Just as meat from a kosher animal is permitted— even though muscle tissue requires blood for its growth—lab-grown meat might also be considered kosher, even if blood is used to feed the cells and promote growth.

However, these arguments are not universally accepted. The Poskim with whom OK Kosher consulted do not find sufficient merit in these points to allow the use of serum. First, serum is the residual component of blood after the cells have been removed, making it difficult to claim that it loses its Halachic status as blood. Second, equating the natural process in a living animal to an artificial one performed in a lab presents a challenge. While it is true that blood is essential for the growth of meat in living animals, it is hard to argue that using blood artificially in a lab to promote cell growth is the same as the natural process.

Since serum is a key component in the production of lab-grown meat, companies that are looking to produce kosher lab-grown meat are working hard to find suitable replacements.

Fleishig or Pareve
Is cultured meat considered fleishig (meat) or pareve (neutral)?

The answer to this question primarily depends on the source of the original cells. If the cultured meat originates from an egg (only applicable to poultry), it is pareve. If the stem cells come from parts of the meat, in the case of all mammals, there are two opinions of the status.

There is a well-known machlokes between the Chasam Sofer and Pri Megadim regarding liquid that is extracted from a piece of meat. The Chasam Sofer² says that such an extract is not considered “meat” according to the Torah, only mi’d’rabbanan. However, the Pri Megadim³ says that even this is considered meat according to the Torah.

In our case, the lab-grown meat, which is sourced from meat cells, is comparable to this meat extract. It follows then that according to the Chasam Sofer, the lab-grown meat is certainly not considered meat mi’d’oraisa; it might also not be considered fleishig, even mi’d’rabbanan,
once additional factors are taken into consideration. However, according to the Pri Megadim, lab-grown meat is definitely considered fleishig.

As a final psak, the Posek of OK Kosher ruled that lab-grown meat derived from parts of the meat is fleishig.

Ma’aras Ayin
In situations where lab-grown meat might be considered pareve, the question then arises: What about ma’aras ayin? Can someone eat that piece of “meat” with cheese, or does ma’aras ayin prohibit such a combination?

The Shulchan Oruch mentions that if one is drinking almond milk during a fleishig meal, one should have almonds on the table to clearly indicate that the milk is almond milk, not animal milk.⁴ The same principle can be applied to our situation.

Certainly, since this industry is still emerging, ma’aras ayin is relevant. If one wanted to eat pareve lab-grown poultry with dairy, they would be required to have some indication nearby to clarify that their “meat” is indeed pareve.

However, if these products eventually become so common and widespread that people will immediately understand that the meat is pareve, the need for a sign would diminish, and ma’aras ayin might no longer be a problem.

There is another argument that vegan cheese and plant-based meats are now quite common, so it’s not unusual to see people eating a kosher “cheeseburger,” and therefore, ma’aras ayin no longer applies. Despite this argument, the policy of major kosher agencies for certified
restaurants or events is to indicate on the menu that the faux “meat” or “dairy” is vegan or fake.

While plant-based cheeses and meats are certainly commonplace, the leniency does not extend to a new product like pareve lab-grown meat. Therefore, for such products, ma’aras ayin would still be a concern, as explained above.

In conclusion, the lab-grown meat industry is relatively new and constantly changing with innovations in technology. At present, given the inherent non-kosher status of serum, it is very difficult to produce lab-grown meat. If this problem is overcome, it could be possible to produce kosher lab-grown meat if the starter cells come from a kosher, shechted animal and all culture mediums are also kosher. The resulting meat would have the Halachic status of regular meat, unless (in the case of poultry) the cells were obtained from an egg.

1 Weekly shiur by Rav Asher Weiss שליט”א , Parshas Shemos 5782.
שו”ת חת”ס יו”ד סי’ פא 2
פ”ד סי’ פא ס”’ק א 3
4 There was a discussion if this applies to margarine and pareve ice cream, as well, but our Posek ruled that those are common foods and it is not necessary. Since almond milk is specifically mentioned in Shulchan Oruch, we should continue the practice.