How Do We Make Kosher Cheese?

Question: Is there a need for kosher cheese to cost such a premium over non-kosher cheese?

Before discussing the halachic issues involved in manufacturing cheese, we need to explain the basics of cheesemaking. Hashem made cow’s milk contain all the nutrients necessary for a newborn calf to grow big and strong until it is ready to be self-supportive by mowing the lawn – I mean, by eating grass for its nutrition. The major components of milk are lactose, or milk sugar, which provides the carbohydrates a young calf needs; casein and other proteins; cream (which is the fat component); various other nutrients, including calcium for healthy bones; and about 90% water, which keeps the other ingredients in suspension or solution. To make cheese, one causes the casein to precipitate (separate) out of the fluid milk and then to coagulate. The coagulated part of the milk, called the curd, separates from the rest, which is the whey.

What is the prohibition called gevinas akum, and why did Chazal prohibit it?

The origins of the rabbinic prohibition banning non-Jewish cheese are mentioned by the Mishnah (Avodah Zarah 29b), which records that Rabbi Yehoshua evaded explaining why the Sages prohibited cheese. In actuality, the Mishnah and the Gemara (Avodah Zarah 35) mention seven possible reasons why Chazal prohibited consumption of gevinas akum:

(1) The first reason mentioned by the Tanna, Rabbi Yehoshua: Because the gentiles set it using the stomach of a non-kosher slaughtered calf.

This approach is later reiterated in the Gemara by Rabbi Yochanan.

(2) The second reason mentioned by Rabbi Yehoshua: Because the gentiles use the stomach of a calf that had been offered for idol worship.

(3) Rabbi Yehoshua ben Levi: The milk may have been left in a place that snakes could poison it with their venom.

(4) Rabbi Chanina: The milk may have been adulterated with milk of a non-kosher species. Although most non-kosher species do not allow themselves to be milked, camels, donkeys, and mares (female horses) can all be milked and produce palatable product. Although milk from non-kosher species contains very little casein and thus cannot be made into cheese, some fluid remains in the cheese that could contain non-kosher milk.

(5) Rav Ada bar Ahavah: The surface of the cheese may be coated with lard.

(6) Rav Chisda: That non-kosher wine vinegar was used to set the cheese.

(7) Rav Nachman bar Yitzchak: That juice of an orlah fruit may have been used to set the cheese. The Torah (VaYikra 19:23) prohibits eating or benefiting from fruit grown on a tree during its first three years. Those fruits are called orlah, and the prohibition of the Torah applies whether the tree was planted by a Jew or a gentile, and whether it grew in Eretz Yisroel or in chutz la’Aretz.

The Rambam in his discussion of these laws mentions setting cheese with the juice of figs. Today, we extract an enzyme known as ficain (also known as ficin), usually from the sap of the fig, which can be, and is, used to make certain varieties of cheese.

As we will soon see, the Rishonim question whether these seven opinions are in dispute – meaning that each authority holds his reason to the exclusion of the others, or that they are each citing a different reason for the prohibition, and that the cheese was prohibited because of any of the reasons.

I want to share with you a curiosity: While researching information for this article, I discovered a forty-year-old article describing how one manufactures cheddar cheese (by the way, the origin of the name is that this cheese was originally developed in Cheddar, a village in England), which reports that the cheese was made by adding calf stomach rennet to the milk so that it curds, heating the curd, going through several processes to carefully remove “every scrap” of whey, pressing the curd and then plunging it into hot water briefly to form a thin rind, and then greasing the rind with pure lard to keep the shape and thicken the rind. Thus, three of the reasons mentioned by the Gemara to prohibit cheese were very much applicable to this cheese – the use of non-kosher rennet; the use of lard; and the remaining uncurded milk in the cheese which could contain adulterated milk, were it not processed so carefully to remove it all. Obviously, contemporary kosher cheddar cheese must use a different source for the rennet, and a substitute for the lard; but are those the only differences between kosher cheddar and non-kosher?

Why did Rabbi Yehoshua hide the reason?

Although we now have some background as to why Chazal prohibited gentile cheese, we have as yet no idea why Rabbi Yehoshua was reticent to explain the origin of the prohibition. However, the Gemara (Avodah Zarah 35a) does explain his concern, in the following passage:

“Why did he not reveal the true reason? As Ula explained: ‘When the scholars of Eretz Yisrael decreed a new prohibition, they did not reveal the reason for twelve months — lest someone dispute their reason and be lax in its observance.'” Thus, we see that even when the prohibition began, no reason was given, out of concern that this might affect whether the takkanah would be properly observed.

We find this issue echoed in a later dispute. In the times of the Rishonim, there were areas of Europe, particularly in Italy and parts of France, where there was a long-established practice to be lenient regarding the consumption of the local cheese of non-Jews. The lenience was based on the fact that the Jews knew the ingredients used by the gentile cheesemakers and that none of the concerns mentioned by the Gemara was germane. The cheese was set with “flowers,” some variety of plant-based enzymes. I am told that, to this day, there are cheeses in some parts of Europe which use an enzyme found naturally in a variety of thistle. Perhaps, this was the type of cheese that these communities used.

In any instance, many communities were in the practice of using gentile cheese and found halachic backing for this position. (Several Rishonim quote this lenient position in the name of the Geonei Narvona.) Tosafos quotes Rabbeinu Tam as saying “that we do not find an obvious reason to prohibit gevinas akum.” Rabbeinu Tam felt that the different opinions quoted in the Gemara are in dispute, and that the authoritative position for the gezeirah of gevinas akum is that of Rabbi Yehoshua ben Levi — that the cheese may be contaminated with snake venom. Rabbeinu Tam then opines that according to Rabbi Yehoshua ben Levi, the prohibition of gevinas akum was never instituted in a place where snakes are not commonly found.

However, most Rishonim rejected this reasoning, contending that the prohibition against gentile cheese exists even when none of the original reasons apply. They contend that the prohibition has a halachic status of davar shebeminyan, a rabbinic injunction that remains binding even when the reason the takkanah was introduced no longer applies, until and unless a larger and more authoritative body declares the original injunction invalid. Since a more authoritative beis din never rescinded the prohibition on gentile cheese, it remains, even when none of the reasons apply (Rambam, Maachalos Asuros 3:4; Rashba, Toras HaBayis page 90b; Semag, Mitzvah 223; Tur, Yoreh Deah 115). Others even contended that Rabbeinu Tam himself never permitted gevinas akum, but that his comments were meant to be theoretical in nature and not a definitive ruling (Semag; Semak).

The Shulchan Aruch rules in line with the majority opinion that there is no halachic basis to allow the practice of the Italian communities which permitted use of the local gentile cheese. The Rama follows a moderately more lenient view, permitting use of gentile cheese only in a place where one can ascertain that there was a long-established custom to permit it. Thus, today no one would be able to use gentile cheese, with the possible exception of an Italian community that can prove that they have such a tradition going back at least eight hundred years.

How is kosher cheese made differently from non-kosher cheese?

Having established that almost universal opinion contends that the prohibition against gentile cheese is alive and well even when none of the concerns apply, we need to clarify how one makes cheese in a way that it is considered Jewish cheese, not gentile. Does the cow or the milk require immersion in a mikveh and acceptance of mitzvos to become Jewish?

To resolve this issue we find a dispute between two major halachic authorities, the Rama (Yoreh Deah 215:2) and the Shach. These two authorities dispute concerning the definition of gevinas Yisrael; or, in other terms, what removes a cheese from the categoric prohibition of gevinas akum. To describe the dispute very succinctly, we could say that the Rama contends that supervision makes the cheese kosher, whereas the Shach insists that a Jew must be involved significantly in the processing of the cheese.

A Mashgiach resolves the problem.

The Rama contends that a Jew observing the production of cheese makes the cheese gevinas Yisrael, which is, by definition, not subject to the prohibition of gevinas akum. In his opinion, this is true even when the milk and curding agents are all owned by a gentile and even when gentiles performed all the steps in the cheese production.

The Shach takes tremendous issue with this approach of the Rama, contending that if a gentile owns the milk, the acid, and the enzyme, and he places the acid or enzyme into the milk, the resultant cheese is prohibited as gevinas akum, even if an observant Jew supervised the entire production! The Shach rallies support for his position from the wording of the Mishnah, which, when describing the prohibition against chalav akum, prohibits milk “milked by a gentile without a Jew watching,” whereas when discussing gevinas akum, the Mishnah simply prohibits “the cheese of gentiles,” omitting the proviso that a supervising Jew is sufficient to remove the prohibition. According to the Shach, the only whey (or did I mean “way”) to avoid gevinas akum is to have a Jew place the curding agent into the milk, or to have the Jew own the milk or the cheese. In these instances, the cheese is now considered “Jewish” cheese, because it was either owned or manufactured by a Jew.

The Shabbos Problem

Those who followed the Shach’s approach requiring the Jew either to make the cheese or to own it, occasionally ran into the following practical problem. In order to make the cheese kosher, they needed to arrange for a Jew to add the enzyme or acid to the milk. This could easily be done if the price was right. If the gentile ordinarily used non-kosher rennet, the Jew would supply his own kosher rennet. However, what was one to do when the gentile decided that the best day to set the cheese was on Shabbos? It is a desecration of Shabbos to add rennet into milk on Shabbos – and, according to the Shach, a Jew must put in the rennet to avoid a problem of gevinas akum!

This entire problem does not exist according to the Rama, since the Jew can simply oversee the work that the non-Jew is performing. The Jew himself is performing no melacha, and the non-Jew does not have to keep Shabbos. Furthermore, no violation of amira le’nachri, having a gentile perform melacha for a Jew, is involved, since the gentile is working on Shabbos as his own decision and for his own purposes.

The Pri Chodosh, who sides with the Shach’s position regarding the dispute concerning what makes a cheese “Jewish,” discusses the problem of what to do when the gentile wants to make the kosher cheese on Shabbos. He concludes the following:

If the Jew orders a certain quantity of cheese, the cheese is considered gevinas Yisrael. Since this cheese is being made specifically for the Jew, the Jew is considered the owner as soon as the cheese is manufactured, thus eliminating the prohibition of gevinas akum. This is true even if the Jew did not participate in the manufacture.

The Pri Chodosh also discusses another case: What is the law if the cheese is manufactured as a partnership between the Jew and the gentile? In this situation, must the Jew add the rennet to the milk to avoid a concern of gevinas akum? The Pri Chodosh rules that lechatchilah the Jew should add the rennet to consider this cheese kosher, but be’dei’evid, if he did not do so, the cheese is permitted, since the Jew is a partial owner.

However, the question is: Why does the Pri Chodosh permit this only be’dei’evid? Logically, this cheese should not be included under the prohibition of gevinas akum, since there is partial Jewish ownership.

It seems that the Pri Chodosh is somewhat concerned because part of the cheese is being made for the gentile – and that quantity of the cheese might be considered gevinas akum – whereas where the Jew is purchasing outright a certain quantity of cheese, whatever is made for the Jew is considered gevinas Yisrael and therefore is permitted.

Another Approach

The Noda BiYehudah (II Orach Chayim #37) discusses a similar case, where a Jew is “renting the schvag” of a non-Jew for the purpose of producing cheese. I do not know the meaning of the word schvag, and in many inquiries about the subject I have found no one else who knows either, but from the context in which the Noda BiYehudah uses the term, it seems that this was a Slavic word for a cheese factory. The case is that the Jew is paying the gentile to use his own facility to produce cheese for the Jew. Again, the Noda BiYehudah is faced by the same problem that the Pri Chodosh discussed: What should one do on Shabbos?

The Noda BiYehudah sides with the Rama: as long as the Jew supervises the process, the cheese is kosher, mentioning that this is the accepted practice, and that several earlier luminaries ruled this way.

In addition, the Noda BiYehudah demonstrates that the dispute between the Rama and the Shach originates as a machlokes Rishonim in which most authorities rule like the Rama, whereas the Maharam of Rottenberg held, like the Shach, that gevinas akum applies unless the Jew is the owner or the manufacturer.

The Noda BiYehudah adds the following point. He contends that when the Jew intends to purchase the cheese and also supplies the rennet, the Jew is already considered the owner of the cheese. Under these circumstances, there is no problem of gevinas akum, even according to the Maharam and the Shach. The Noda BiYehudah concludes that, under these circumstances, a gentile may himself actually produce the cheese without it becoming prohibited. Whereas the Pri Chodosh (115:15) permitted consuming cheese produced this way only be’dei’evid, that is, if it has been produced already, the Noda BiYehudah rules that lechatchilah one may produce kosher cheese this way.

Owning just the rennet

Based on the explanation of the Noda BiYehudah, some contemporary rabbonim have suggested that it is sufficient for the Jew to own the rennet. Others take issue with this approach, contending that this is sufficient only when the cheese is being produced specifically for Jewish consumption, whereas in the modern world, the cheese is usually produced for general consumption, and the non-Jewish company intends to market the cheese. According to the Orthodox Union Kashruth Division, Rav Yisrael Belsky rules that the Noda BiYehudah permitted only a situation when the Jews rented the cheese-plant and planned on purchasing the finished cheeses. The Noda BiYehudah contended that owning the rennet suffices to give the Jew a partial ownership in the cheese when it is a first step towards taking full possession. However, when the Jew now has no intention of ever owning the cheese, this approach is insufficient to create gevinas Yisrael.

Other rabbonim ruled that if the Jew owns the milk and the rennet, then the cheese produced is gevinas Yisrael according to all opinions. Subsequent to its production, the gentile then purchases the cheese back from the Jew, so that he markets it as his own cheese. However, I know of responsible, knowledgeable rabbonim who permitted cheese based on this heter, usually adding other requirements. For example, in one instance the rav made a kinyan on the factory and all its vessels, so that he would own the cheese as it was made. Another suggestion was that the rav remain a partial owner of the cheese as it was made, and that he sell his share in the finished cheese, after its manufacture was complete, back to the company in exchange for his “hechsher fee.”


The Gemara teaches that the rabbinic laws are dearer to Hashem than the Torah laws. In this context, we can explain the vast halachic literature devoted to understanding the prohibition of gevinas akum, created by Chazal to protect the Jewish people from various different sins. We should always hope and pray that the food we eat fulfill all the halachos that the Torah commands us.