Insights into Halacha

For the week ending 28 June 2014 / 30 Sivan 5774

Halachic Insights into Genetically Engineered Meat

by Rabbi Yehuda Spitz
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Recently, the BBC broke an exclusive story[1]; one that many claim has potential to change the world. Professor Mark Post of Maastricht University in the Netherlands has done the impossible: he has created the world’s first laboratory grown hamburger. While news of this $325,000 hamburger was welcomed by environmentalists, animal rights activists, and doom n’ gloom predictors alike; and others defining it as “just plain weird”, our concern is how such a creation would be viewed through the lens of halacha.


This hamburger was created by extracting stem cells (the body’s master cells; templates from which specialized tissue develop) from a cow’s muscle tissue. These stem cells were cultured and multiplied with nutrients and growth promoting chemicals, and later coalesced, forming tiny strips of muscle fiber. Approximately 20,000 of these strips were needed to create just one hamburger.

It is important to note that currently, with the price tag of test tube beef being in the six figures, its production unrealistic in the foreseeable future, and the exact scientific process kept under wraps, this halachic discussion is primarily academic, firmly entrenched in the realm of theory. If and when lab grown burgers become affordable and mainstream, its status would need to be appraised by the expert Rabbanim of the time, based on the actual metzius of how these burgers are made.

Several Rabbis addressed the issue of whether or not such a burger should be considered kosher and even possibly pareve, yet, based on different precedents cited, their theorized conclusions were quite diverse[2]. Would this man made and modified meat be considered kosher or treif? Pareve or fleishig? This article sets out to address the different potential halachic possibilities.

Magical Mystery Meat

Truthfully, meat created from non-traditional sources has a tradition and precedent, and is already mentioned in the Gemara[3], once regarding meat that came down from the heavens, and again concerning meat that was created using the Sefer Yetzira, “the Book of Creation” attributed to Avraham Avinu.

The Malbim writes that meat created using the “Sefer Yetzira” is essentially pareve. That is why Avraham Avinu was able to give the visiting Angels a meal containing both milk and meat; the meat was truly pareve, as Avraham created it that day[4]! The Cheshek Shlomo, Av Beis Din of Vilna in the nineteenth century, extrapolates further. He averred that ergo, milk from a cow that was created via the “Sefer Yetzira” is not truly ‘milchig’, rather pareve too[5]. If so, some opine that our test tube burger should be considered not only kosher, but pareve as well, due to this halachic precedent.

However, even according to this theory, in order for the burger to receive this halachic status, the cow that the stem cells were harvested from would need to have had a proper shechita, precluding a biopsy from a live cow. As although meat created utilizing the “Sefer Yetzira” should not technically need ritual slaughter, as it was not truly alive[6], nevertheless, shechita still would be mandated, due to the Rabbinic injunction of Maris Ayin[7]. The most basic definition of this law is the prohibition of taking actions which strictly speaking, are permitted according to halacha, but nevertheless give onlookers the impression that we are doing something halachically forbidden[8]. Accordingly, the same would apply to our home grown hamburger, and shechita would be required.

Gelling Together

Another possible precedent posited was to compare the lab burger’s status to that of gelatin, which is a whole separate discussion in itself. Already controversial when cited in halachic literature over a century ago, gelatin’s kashrus status is still being debated.

Gelatin is a translucent, colorless, and flavorless solid substance, derived from collagen obtained from various animal by-products, mainly the bones and skin of cows and/or pigs. It is the gelling agent that makes marshmallows and ‘gummy bears’ gummy.

The process to make gelatin is an interesting one: the collagen in the bones and skin of the animals is converted into ossein by soaking them in hydrochloric acid. Then it is soaked in lime for about a month, followed by a wash in sulfuric acid[9]. (Do not try this at home![10])

Contemporary authorities debate gelatin’s halachic status. Although Rav Chaim Ozer Grodzinsky zt”l permitted gelatin made utilizing hard cow bones, and Rav Ovadiah Yosef shlit”a, even allowed gelatin made from cow skins[11], nevertheless, when this sheilah arose in the 1950’s - 60’s most Gedolim based in America, including Rav Aharon Kotler zt”l, Rav Eliezer Silverzt”l, Rav Moshe Feinstein zt”l,and Rav Yosef Eliyahu Henkin zt”l, [as did most later poskim in Eretz Yisrael], all unequivocally prohibited gelatin, unless it was derived from properly shechted kosher animals[12]. Nowadays, although the Israeli Chief Rabbinate permits gelatin as kosher and has a distinct designation, “kosher l’ochlei gelatin”, on the other hand, no Mehadrin kashrus agency or Badatz in Eretz Yisrael, nor no mainstream certifying agency in Americaconsiders real gelatin kosher[13], unless it is produced from properly shechted kosher animals.

Back to our test tube burger, if it can be compared with gelatin, as it is essentially a meat based product that has undergone extreme change via chemicals, its halachic status would depend on the above machlokes. According to those who rule leniently with gelatin that is not kosher based, the same dispensation should be given to our Petri dish piece of meat and the actual source of the original stem cells should not trouble us too much. Yet, according to the mainstream opinion that kosher gelatin must originate from a shechted kosher animal, the same should apply to our lab created burger and be mandated for it as well.

Another interesting outcome of this machlokes is another. Even amidst the mainstream ruling, there are differences between the opinions. For example, Rav Moshe held that real kosher gelatin made from shechted cows is considered completely pareve, while Rav Aharon Kotler was of the opinion that lechatchila one should still consider it somewhat fleishig and not mix it with milk. If we use gelatin as our halachic springboard, the same debate should also technically apply to our home grown hamburger. Accordingly, those who follow Rav Moshe’s psak regarding kosher gelatin being pareve (for example, the OU), should also assume that the lab burger is also. On the other hand, those who follow Rav Aharon’s shitta should still ensure that no milk is mixed amid the man made modified meat.

Catalyst Conundrum

Although it would seem tenuous at best to consider microscopic cells removed from a cow’s shoulder and undergoing chemical treatment as a potential violation of the Biblical prohibition of eating ‘Aver Min HaChai’, ‘a limb from a live animal’[14], nonetheless, there is strong basis to still consider our homegrown hamburger meaty.

Halachically speaking, something that is present in minute quantities in a mixture is generally considered nullified as long as there is at least a 60 to 1 ratio against it (battel b’shishim)[15]. Although this would imply that the Petri dish patty would be considered kosher even if it was harvested from a non-kosher source, as the final patty has 20,000 muscle fibers grown from a few stem cells, on the other hand it is not so simple, as every rule has its exceptions.

One of the exceptions is a case of a ‘Davar HaMaamid’, an essential ingredient in the makeup of a product that establishes its form. This catalyst impacts it tremendously, far greater than its size belies. A prime example of a ‘Davar HaMaamid’ is the small amount of a calf’s stomach lining (rennet) placed in a huge vat of milk that turns it to cheese[16]. The halachic status of a non-kosher ‘Davar HaMaamid’ is that it cannot be nullified, no matter how infinitesimal it seems compared to the final product[17].

It is entirely possible that the same rule should apply to our lab burger. Since the whole hamburger’s essence stems from those original miniscule meaty stem cells, it is feasible that they would have the halachic status of a ‘Davar HaMaamid’. If so, and they were harvested from a non-kosher animal, it might just deem the final product non-kosher as well. However, if these cells would be extracted from a properly slaughtered kosher animal, then the lab grown burger would be considered kosher and although me’ikar hadin should be considered pareve[18], it still might possibly be deemed somewhat fleishig (meaning not to eat with milk) if the cells are reckoned substantial enough to be considered meat; similar to Rav Aharon Kotler’s ruling regarding gelatin.

On the other hand, sometimes even the exceptions have exceptions. For example, a product produced via a non-kosher ‘Davar HaMaamid’ can still sometimes be permitted. If there is another kosher catalyst involved in the production of an item, it can be considered a “Zeh V’Zeh Gorem”. This terminology refers to a product that was not manufactured exclusively using a non-kosher ‘Davar HaMaamid’, but rather utilizing it as a combination catalyst complementing another kosher one. The halacha in such cases deemed a “Zeh V’Zeh Gorem”, is that the basic rules of battel b’shishim are back in effect, and only 60 times the original non-kosher catalyst in its makeup is mandated in order to permit the final product[19]. It is possible that there are additional kosher “Devarim HaMaamid’ used in the manufacture of the man-made burger. If so, and there is present a ratio of 60 times against the original meaty stem cells, it might be deemed pareve and possibly permitted.

Yet, to further complicate matters, many authorities maintain that in order for combination catalysts to qualify as a “Zeh V’Zeh Gorem”, the non-kosher catalyst must not have the strength to fully impact and establish the item’s form; only in tandem, as a ‘tag team’ of sorts, with the kosher catalyst. Otherwise, according to these decisors[20], it would still maintain its ‘Davar HaMaamid’ status and deem the final product non kosher as well, due to its inability to be nullified. Additionally, to use a non-kosher ‘Davar HaMaamidl’chatchila, even if it is considered a “Zeh V’Zeh Gorem”, might nonetheless transgress the prohibition of “Ain Mevattlin Issur” and be prohibited[21].

So, which of these describes our lab grown burger? Your guess is as good as mine. That is why until the whole process is made public knowledge all we can do is theorize as to the potential halachic possibilities.

Kosher Cheeseburgers?

However, it is important to note that even following one of the premises that lab created meat would maintain pareve status, it still would not denote a kosher cheeseburger. The permissibility of such would depend on the laws of Maris Ayin. Since this halacha depends on how common an item is[22], with a $325,000 price tag, a potential kosher cheeseburger is a long way off!

As stated previously, this whole cutting edge scientific discussion of genetically engineered beef is currently purely academic. We are enjoying some food for thought, not actually defining it halachically!

It’s important to realize that such technological advances were foreshadowed thousands of years ago by the wisdom of our Sages, discussing meat created via unconventional means. Time and technology have once again proven wrong those who might scoff at our Aggadic Mesorah.

Postscript: After completing this article, this author was notified by noted food scientist Arlene Mathes Scharf of that an additional factor in the production of the lab grown burger was made public, that growing this "meat" involved using fresh calf blood as the growth medium. If so, it definitely might change the lab burger’s potential kashrus status. First of all, if it is soaking directly in blood for more than 24 hours straight it can be considered kavush k’mevushal and prohibited (at least Rabbinically)[23]. Additionally, if blood is used as an actual growth medium it would seem to be a ‘Davar HaMaamid’ and would never be battel. Furthermore, even if it might qualify as a “Zeh V’Zeh Gorem”, nonetheless, if it is considered such an integral part of the growth process, presumably at no time would there be present a ratio of 60 against it. Consequently, if proven accurate, use of blood as the growth medium can complicate matters, and would seemingly make production of the Petri dish patty highly problematic.

Just another excellent reason to ascertain the actual metzius when viewing innovation via the lens of halacha.

This author wishes to thank Chaim Orelowitz and Yisroel Meir Wachs, former Talmidim, for their impetus in this author’s interest and research in this topic.

This article was written l’zechus for Yaacov Tzvi ben Rivka and Shira Yaffa bas Rochel Miriam v’chol yotzei chalatzeha for a yeshua teikif umiyad.

For any questions, comments or for the full Mareh Mekomos / sources, please email the author:

Rabbi Yehuda Spitz serves as the Sho’el U' Meishiv and Rosh Chabura of the Ohr Lagolah Halacha Kollel at Yeshivas Ohr Somayach in Yerushalayim. He also currently writes a contemporary halacha column for the Ohr Somayach website titled “Insights Into Halacha”.

[3]Sanhedrin 59b and 65b. Although this author has not seen a discussion of what the proper bracha would be, and if a bracha is even mandated, regarding this “magical meat”, there actually is such a discussion regarding the munn, manna that came down from Heaven. See Rav Nissan Kaplan’s Shalmei Nissan (on Perek Keitzad Mevorchin pg. 304 - 305; who cites many shittos on topic) at length. The Rem”a M’Fano is even quoted as mandating “Hamotzi lechem min hashamayim”.

[4]Malbim (HaTorah V’HaMitzva, Parshas Vayera Ch.18, verse 8). A similar explanation can also be found in the Pirkei D’R’ Eliezer (cited in Yalkut Reuveini on Parshas Vayera) and by the Chessed L’Avraham (ancestor of the Chida; Ein Mishpat Nahar 51). The Pardes Yosef cites this as well (Parshas Vayera Ch. 18, pg. 115, end 1st paragraph and Parshas Vayeishev Ch.37, pg. 268, end 1st paragraph). See also Darchei Teshuva (87, 29). There are many other interpretations of how to understand Avraham Avinu’s actions. See previous article titled “Ma’aseh Avos = Halacha L’Ma’aseh” at length.

[5]Cheshek Shlomo (end Y”D 98, s.v. v’da). He is attempting to resolve the Kreisi U’Pleisi’s question (81, 7; at length) on the Gemara Bechoros (6b), why it did not cite Avraham Avinu’s serving of milk as proof that milk is not considered Aver Min HaChai (see Shulchan Aruch Y”D 81, 5), which would be prohibited even for non-Jews as it is one of the Seven Mitzvos of Bnei Noach (see Rambam Hilchos Melachim Ch. 9, 10 and Aruch Hashulchan Y”D 62, 4 & 5). A similar solution is offered by Rav Yitzchok HaLevi Horowitz of Hamburgin his ‘Metaamei Yitzchak’ (glosses on the Kreisi U’Pleisi, ad loc). On the topic of the Seven Mitzvos of Bnei Noach, see Rabbi Yirmiyahu Kaganoff’s fascinating article “Noahide Halacha 101 or Meet the Adams Family”, also found in his recent seferFrom Buffalo Burgers to Monetary Mysteries”.

[6]Shlah (Shnei Luchos HaBris vol. 2, Torah Shebeksav, Parshas Vayeishev), explaining that this was what the Shevatim were eating that Yosef assumed was Aver Min HaChai.

[7]Pischei Teshuva (Y”D 62, 2). See also Darchei Teshuva (ad loc. 6). For more on issues related to animals created via “Sefer Yetzira”, see Pardes Yosef at length (Parshas Vayeishev Ch. 37, ppg. 267 - 269).

[8]See previous article titled: “Margarine, Misconceptions, and Maris Ayin” at length.

[9]As per Rabbi Eliezer Eidelitz’s “Is It Kosher?” pg. 122.

[10]I still remember the poem my high school Chemistry teacher, Mr. Ezra Roberg, drilled into us regarding the potential dangers of sulfuric acid: “Johnny was here yesterday; today he’s here no more. For what he thought was H2O, was H2SO4.”

[11]Shu”t Achiezer (vol. 3, 33, 5), Shu”t Yabea Omer (vol. 8, Y”D 11). One of the primary points for permitting is that of “panim chadashos”. During the process of producing gelatin, the original bones are completely destroyed by the various acids et al., and the inedible gelatinous results bear no resemblance, not even by taste nor form to the original, and would therefore be considered a completely new item. This would be similar to the rule of ‘or hakeiva’ that has become as hard as wood losing its status of meat (see Rema Y”D 87, end 10). However, Rav Chaim Ozer’s allowance for gelatin was based on certain processes of the day (processed from hard cow bones, as he wrote). It is highly doubtful that if he had seen gelatin produced from pig flesh he would have still maintained the same hetter (see footnote 13). The issue of “hard” versus “soft” (edible) bones is based on a machlokes between the Minchas Yaakov (Shu”t 15) and Pri Megadim (Y”D 87, S.D. 22) how to understand the Shulchan Aruch’s choice of words (Y”D 87, 7) defining bones’ halachic status, as well as the Shach in Hilchos Taaruvos (Y”D 99, 1). This was touched upon in previous article titled “The Chicken Bone ‘N’ Cholent Commotion”. There were other poskim who permitted gelatin over the years, including the Divrei Yosef (Shu”t Y”D 4), the Tzitz Eliezer (Shu”t vol. 4, preface and vol. 20, 34), and Rav Ben Tzion Abba Shaul (Shu”t Ohr L’Tzion vol. 1, O.C. 34, pg 90); yet, several of them including the Melamed L’Hoyeel (Shu”t vol. 2, Y”D 35), Rav Tzvi Pesach Frank (Shu”t Har Tzvi Y”D 83), and Rav Yechezkel Abramsky (Chazon Yechezkel, Zevachim, Shu”t 5), qualified their permissive rulings, stating that only b’dieved or for a Choleh may dispensation be given.

[12]Rav Aharon Kotler (Shu”t Mishnas Rav Aharon 16 & 17), Rav Moshe Feinstein (Shu”t Igros Moshe Y”D vol. 2, 27), Rav Yosef Eliyahu Henkin (Eidus L’Yisrael pg. 177). Rav Silver’s shitta is well known; aside for publicizing a letter in 1950 against a hechsher certifying a well known gelatin product, he has written at least two separate teshuvos on topic: one to Rav Zelig Reuven Bengis of the Eida HaChareidis in Yerushalayim – reprinted in Kovetz Yeshurun (vol. 12, pg. 241), and another in Kovetz Kerem (Year 2, vol. 1 pg. 5, Tishrei 5713). Other poskim in Eretz Yisrael who ruled this way include the Chazon Ish (Y”D 12, 7), the Minchas Yitzchok (Shu”t vol. 5, 5), Rav Yosef Shalom Elyashiv (Kovetz Teshuvos vol. 1, 73, 3), Rav Shmuel HaLevi Wosner (Shu”t Shevet HaLevi vol. 7, 135), Rav Moshe Sternbuch (Shu”t Teshuvos V’Hanhagos vol. 2, 381), and Rav Menashe Klein (Shu”t Mishna Halachos vol. 3, 111). One of their main points of contention is questioning the application of “panim chadashos” to gelatin, as the collagen which is the basis for the gelatin, was part and parcel of the original bones and skin the whole time. Additionally, the fact that one wants to use it as a food item might make it considered “Achshevei”, and return it to its original status, which would be treif. This means that one’s intention to eat it, although currently inedible, would halachically reconsider it a food item; for an example of how this might work, see Shu”t Shaagas Aryeh (75). Moreover, nowadays pig byproducts (hides and skins etc.) are often used in making gelatin, and the Rambam (Hilchos Ma’acholos Asuros Ch. 4, 21) states that the hides of domesticated pigs have the halachic status of meat, and are considered edible and are most definitely not kosher. Thus, even those who argued that gelatin made from the hides of (non halachically shechted) beef or from bones is still me’ikar hadin kosher, nevertheless, would have a harder time defending that position as relates to porcine gelatin.

[13]I used the term “real gelatin”, as nowadays kosher “gelatin” made from agar agar (seaweed) or from fish is quite commonplace, and do not have these same halachic issues as true gelatin made from possible neveilos u’treifos. Perhaps the halachic issues of gelatin will be further explored in a future article IY”H.

[14]See Tur/Shulchan Aruch Y”D 81 at length. See also footnote 5.

[15]This is the standard rule of nullification in halacha, if there is present 60 times the amount of non-kosher, then it is considered nullified. See Shulchan Aruch Y”D 98.

[16]OK, one might ask, then how did they make kosher cheese before synthetic rennet was discovered, if the real rennet is never battel? See Shach (Y”D 87, 30), Shu”t Rabbi Akiva Eiger (vol. 1, 207), Shu”t Chasam Sofer (Y”D 81), Matteh Yonason (glosses to Y”D 87, 9), and Pischei Teshuva (Y”D 87, 19).

[17]See Shulchan Aruch Y”D 87, 11 and relevant commentaries.

[18]See Shulchan Aruch Y”D 87, 11 and relevant commentaries. The basic rule is that a kosher ‘Davar HaMaamid’ wouldindeed be batel b’shishim as opposed to a non-kosher one.

[19]See Shulchan Aruch (Y”D 142, 11) and Rema (Y”D 87, 11), based on the Mordechai (Chullin, Ch.8, 733 and 761).

[20]Including the Taz (Y”D 87, 13), Shach (ad loc., 36; although he concludes tzarich iyun), Pri Chadash (ad loc. 31), Kreisi U’Pleisi (ad loc. Kresi 25 & Pleisi 21), Ba’er HaGolah (ad loc.), Pri Megadim (M.Z. ad loc., 13), and Aruch Hashulchan (ad loc., 42), citing Tosafos in Avoda Zara (68b s.v. l’Rebi Shimon) as proof. However, the Yad Yehuda (ad loc., piha”k 54 & pih”a 26) argues that “Zeh V’Zeh Gorem” applies even when the non-kosher catalyst has enough strength by itself to affect the required change. He maintains that since the whole issue of ‘Davar HaMaamid’ not being nullified is not so clear cut in the earlier poskim [for example, Rabbeinu Tam (Sefer HaYoshor 53, 5), the Ba’al HaMaor (Chullin 42b), Tur (Y”D 87, 11), and Rashal (Yam Shel Shlomo, Chullin Ch. 8, 106) are all of the opinion that ‘Davar HaMaamid’ is battel b’shishim; in fact the Yad Yehuda (pih”a 25) proves that most Rishonim held this way, contrary to how others present their opinions], and that the Mordechai (who first makes this dispensation), and later the Rema, make no mention of such a proviso, [he also gives several other halachic rationales], “Zeh V’Zeh Gorem” will even apply when the non-kosher ‘Davar HaMaamid’ can impact the item sufficiently by itself, as long as a kosher ‘Davar HaMaamid’ is present.

[21]It is important to note that even if the item meets the requirements of “Zeh V’Zeh Gorem”, it is by no means a blanket hetter. The Avnei Miluim (vol. 2, Shu”t 6) explains at length (see also Darchei Teshuva 87, 153) that it is only a hetter b’dieved. To use a non-kosher ‘Davar HaMaamidl’chatchila, even if it is considered a “Zeh V’Zeh Gorem”, would nonetheless transgress the prohibition of “Ain Mevattlin Issur” (see previous article titled “The Coca-Cola Kashrus Controversy” at length) and would be prohibited. [Even so, according to the Imrei Binah (Dinei Basar B’Chalav V’Taaruvos end 6) a kenass would not be mandated, as opposed to a traditional “Ain Mevattlin Issur”, as a “Zeh V’Zeh Gorem” qualifies as K’Mevattel Issur).]

[22]As explained at length in a previous article titled: “Margarine, Misconceptions, and Maris Ayin”.

[23]For the parameters of the halachos of kavush k’mevushal see Tur / Shulchan Aruch and main commentaries to Yorah De’ah 105, 1 at length.

Disclaimer: This is not a comprehensive guide, rather a brief summary to raise awareness of the issues. In any real case one should ask a competent Halachic authority.

L'iluy Nishmas the Rosh HaYeshiva - Rav Chonoh Menachem Mendel ben R' Yechezkel Shraga, Rav Yaakov Yeshaya ben R' Boruch Yehuda.

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