“Rabbi, why doesn’t most hard cheese have a hechsher? After all, the ingredients all seem kosher?”
The above question is often posed to me and my colleagues in the kashrus industry. While the question is simple, the answer is a bit more complex.
Prohibition of Gevinas Akum
Of all dairy products, kosher certification of cheese is the most difficult. The Mishna (Avodah Zarah 29b) states that gevinas akum – cheese made by a nochri – is non-kosher (mi-d’rabbonon – rabbinically prohibited). Many reasons are offered in the Gemara (ibid. 35a-b) as to why Chazal forbade gevinas akum. Many prominent Rishonim and poskim (including the Rif, Rambam and Shulchan Oruch) follow the rationale advanced by Shmuel, who states that the gezerah against gevinas akum is due to the use of non-kosher animal rennet by nochrim in their cheese-making1. Rennet is the enzyme which turns milk into cheese (as will be seen in more detail below), and it originates in calf stomach lining. Shmuel held that the fear that non-Jewish cheese may contain such rennet, derived from nevelah flesh, led Chazal to formulate a gezerah against such cheese. Even though hard cheese normally contains only a very minute amount of rennet (far less than 1/60), nevertheless, since rennet is a dovor ha-ma’amid (a material which gives the product its form), it is not botel (nullified) even in very small ratios. (Shulchan Oruch YD 87:11.) Thus, the fear that cheese may contain non-kosher rennet, which cannot be botel, was the motivation for Chazal to prohibit non-Jewish cheese.
In mainland Europe, the prevalent practice in cheesemaking is still to use animal rennet. In the United States and in England, microbial (artificial) rennet is typically utilized, and many varieties of Portuguese hard cheese are coagulated with thistle flower. However, even if the rennet is derived from kosher sources such as microbial rennet or thistles, halacha states that non-Jewish cheese remains forbidden as gevinas akum (Shulchan Oruch YD 115:2 based on Rambam Hil. Ma’achalos Asuros 3:14 ); only gevinas Yisroel ( “Jewish cheese” ) is permitted.
Gevinas Yisroel
How does one manufacture gevinas Yisroel? The Remo (YD ibid.) stipulates that Jewish presence is required when the cheese is made, and the Shach (ibid. s.k. 20) argues, holding that a Yisroel must himself actually add the enzyme that forms the cheese. The supervision provided by most kashrus agencies normally fulfills both opinions, such that when the mashgiach is present for cheese production (thereby fulfilling the Remo’s requirement), he personally adds the rennet enzyme to the milk for each batch of cheese (thereby fulfilling the Shach’s requirement1).
In the case of many newer cheese factories, which use automated rennet feeders rather than manual incorporation of rennet into cheese vats, the mashgiach activates the rennet feeder for each vat, entering the control room for this purpose every 45 minutes or so to be ready for the next cheese production. In the event that the mashgiach cannot monitor vat activity from this area as well as in cases in which the milk or rennet is Jewish-owned, as will be discussed shortly), many kashrus agencies require the mashgiach to also maintain presence at the vat location, so as to be sure to provide the physical supervision as stipulated by the Remo.
What kind of cheese must be gevinas Yisroel? Common practice (adopted by many kashrus agencies, based on the rationale in Igros Moshe YD 2 s. 45 and approved by Rav Yosef Eliyohu Henkin) is to follow the opinion that that the gezerah of gevinas akum was only declared on hard cheese, as only hard cheese uses rennet to form into curd and was therefore subject to the prohibition. Soft cheese, such as cream cheese and cottage cheese – also called “acid-set cheese” – does not need rennet to coagulate, as it can acidify and form on its own, and such cheese is therefore not subject to the rule of gevinas akum. Nonetheless, the Aruch Ha-Shulchan (YD 115:16) and Chochmas Odom (53:38) seem to hold that even soft cheese is subject to the gezerah of gevinas akum2.
Kosher Cheese Production
Although many poskim hold that cheese made from Jewish-owned milk is automatically gevinas Yisroel (Shach ibid., Chochmas Odom 87:7), and some consider cheese made from Jewish-owned rennet also to be gevinas Yisroel (see Pischei Teshuva 115:s.k. 6), there are – in actuality – very few Jewish-owned farms or cheese factories outside of Eretz Yisroel. Thus, most kosher hard cheese we purchase is manufactured at non-Jewish facilities, which schedule special kosher gevinas Yisroel campaigns with their kashrus agencies.
How is such kosher cheese produced?
All cheese begins with milk, which is usually pasteurized (heat-treated to destroy harmful bacteria). The milk is normally dosed with starter culture, which is non-harmful bacteria programmed to sour the milk for cheese-making.
The milk is then piped into a large vat, where other additives may be present. Vinegar may be used to control pH levels; non-fat dry milk may be added to lower fat content; cream may be added to raise fat content.
Rennet is then incorporated into the vat. Rennet causes the milk to separate into solid curd particles and liquid whey. The curd is collected and molded into larger pieces, after which it is cut.
Some types of Italian cheese (e.g. mozzarella) are made to be flexible and elastic, so as to melt well, stretch and retain their texture. These cheeses have to be cooked in a hot bath ( “cooker” ) after molding.
Before cutting to small sizes and packaging, cheese may need to be brined or aged. Brining is the process whereby cheese is immersed in a very long, spiral tank of salt water, so as to protect the product from spoilage and seal in moisture. Aging is often needed in order to develop the curd and bring out the flavor in many varieties of cheese. Some cheeses are also treated with enzymes called “lipases” which speed up the break-down of fat, thereby significantly enhancing flavor. (Standard lipase is derived from the tongue roots or stomachs of neveilah or non-kosher species of animals, although kosher and artificial forms of lipase are now more readily available.)
Equipment Concerns
Aside from assuring gevinas Yisroel and the kashrus of all ingredients, the kashrus agency must deal with many equipment issues in the above scenario. If the cheese is to be hot-process (i.e. the vat is heated to yad soledes bo [halachic cooking] temperatures when the cheese is made), such as with Swiss and Parmesan production, the vat needs to be kashered, as it has absorbed flavor from non-kosher cheese in previous use. Even if the vat is only used for cold-process cheese (e.g. cheddar or mozzarella), it must be thoroughly cleansed. (There is no problem of kovush [cold absorption over time], as vats do not hold milk or cheese for 24 hours or more.)
Cookers used for mozzarella cheese need to be kashered, and brine used for non-kosher cheese must be replaced. Brine tanks must be kashered or fully covered, so that kosher cheese not absorb non-kosher taste from the tanks’ walls.
All cheese cutters must be abrasively cleansed.
The mashgiach must be present for all kashering and inspection of equipment.
Control of Kosher Labels
How do kashrus agencies assure that non-kosher cheese is not labeled as kosher when the mashgiach is not present? How can one prevent the cheese plant from packaging its own (non-kosher) product in kosher labeling?
In the case of industrial cheese, it is somewhat straightforward. Most kashrus agencies issue letters of certification which state that the cheese is certified only when 1) the supervising rabbi’s signature appears on the packaging, 2) the cheese is accompanied by a letter from the kashrus agency covering each individual batch, or 3) special coded insignias unique to the mashgaich and kashrus agency are applied to the cheese. (The mashgiach controls these insignias and applies or issues them when he is present for kosher productions.)
However, in the case of retail product, the above options are often not practical, as the mashgiach cannot sign each small package of cheese or attach his insignia to it, nor can letters of certification for each batch be expected to accompany every pack of cheese on the supermarket shelf. Rather, for kosher retail cheese, the mashgiach himself must be in control of all packaging and he must meticulously monitor plant activity and production records. This requires a very adept mashgiach who is usually computer-savvy (often needing to program the labeling system to only print kosher packaging when he inputs his code, and able to scan production data via computer).
Hashgocho of retail cheese also requires more “negative supervision”, in which mashgichim are sent to visit the cheese plant when it is making its regular, non-kosher products, to assure that kosher labels are not applied at such times. (Negative supervision is needed for all non-kosher facilities which schedule special kosher productions, but it is more critical in the case of retail cheese manufacturers.)
Some wonder why kosher cheese is so expensive. Although most kashrus agencies are not privy to the product’s profit margin, it is clear that the amount of work involved to obtain the final product is immense.
1 Other rationales presented in the sugya are that gevinas akum is forbidden because of the possibility of non-kosher milk in the cheese’s holes, giluy (milk left exposed overnight, which is or was a hazard), the surface of the cheese being smeared with lard, and use of orlah or non-kosher vinegar coagulants
2 The Aruch Ha-Shulchan argues that even “our gevinoh peshutoh (simple cheese) which is not coagulated“ is prohibited as gevinas akum, as the gezerah was formulated as a dovor she-b’minyan (Maggid Mishneh on Rambam ibid.) and is thus binding even when the reason no longer applies. The Igros Moshe opines that such type of cheese – which does not use rennet as its standard coagulant – was not logically subject to the gezerah, whatever form the gezerah may have taken, as soft cheese is not in the same product category to which Chazal referred; Chazal were only concerned with rennet-set cheese, whether set by animal, vegetable or artificial rennet; cheese which does not use rennet for standard coagulation is not part of the category of cheese included in the prohibThis author thinks the language of the Rambam and Shulchan Oruch seem to support the Igros Moshe: “…They (the rabbis) banned all cheese of akum, whether they coagulated it with prohibited material or they coagulated it with permitted material…” (Rambam ibid. The Shulchan Oruch uses almost identical phraseology.) However, cheese which does not undergo any form of rennet coagulation at all is not referred to by the Rambam or Mechaber as included in the ban. ( Otherwise, and to be more precise, if they held that such cheese falls under the gezerah of gevinas akum, their language certainly should have included cheese which is “coagulated by permitted material or not (manually) coagulated at all…” ) Thus, it seems that the cheese of the Aruch Ha-Shulchan “which is not coagulated” and of the Chochmas Odom (67:7) “which occurs by itself” should not be part of the gezerah, according to the terminology of the Rambam and Shulchan Oruch; otherwise, the Rambam and Shulchan Oruch should have included it in their wording.
Furthermore, it is difficult to even assume that the definition of “cheese” in the Gemara and Rishonim includes what we today call “soft cheese”. The Gemara in Chullin (107b) states that one may place cheese and meat in the same container so long as they do not make contact; in case of contact, the Gemara says that the substances need to be washed off and that there is no need to peel off the contact surfaces. Rishonim and poskim quote this halacha. It is clear that the cheese referred to in the Gemara and Rishonim cannot include what we refer to as “soft cheese”, as this cheese is of a loose texture and commonly moves and even runs, and it would be impossible to state that it may be kept in the same container as meat, for the foods would surely contact due to the soft cheese’s loose consistency. So, too, it is not possible to peel or wash the surface of soft cheese, as there is no solid surface which can be washed or peeled. Thus, we see – at least from this halacha – that “cheese” in the terminology of the Gemara and Rishonim refers to hard cheese and not what we call “soft cheese”.
As noted, the Aruch Ha-Shulchan quotes the Maggid Mishneh (ibid.) as the source for his p’sak that all cheese – even soft – falls under the category of gevinas akum. However, the Maggid Mishneh’s own words do not seem to so indicate: “And this is what the Achronim z“l wrote, that even… if it is known that they (nochrim) do not smear the surface of the cheese with lard…and (even) if it is known that they coagulate the cheese with flower nips, nonetheless, their cheese is forbidden because it is a dovor she-ne’esar b’minyan.” If the Maggid Mishneh (and the opinions he invokes) truly held that soft cheese is subject to the gezerah, he should have written that “even cheese which cannot be smeared with lard [as it is soft and has no surface upon which to smear]…and [even] cheese which requires no (manual) coagulation, is all forbidden…” This would have accurately provided the expansive parameters which the Aruch Ha-Shulchan and Chochmas Odom advocate. Since the Maggid Mishneh limited his illustrations to cases which can only pertain to hard cheese, it seems very convincing that he only had such cheese in mind when addressing gevinas akum.
Despite these arguments, Rav Chisda in the Gemara (AZ 35b) offers a rationale that gevinas akum is prohibited because it is or may be coagulated with (non-kosher) vinegar, and Rashi (d.h. she-ma’amidin) explains that the vinegar about which Rav Chisda is concerned is used as a milk coagulant. Although vinegar is commonly used as an acidulant in both soft and hard cheese, Rashi holds that Rav Chisda addresses vinegar used to actually set cheese. This view, which is the simplest reading of Rav Chisda’s statement, supports the Chochmas Odom and the Aruch Ha-Shulchan’s p’sak that even soft (acid-set) cheese is prohibited as gevinas akum.