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Forbidden Fromage: Kosher Konundrum Part 1


Welcome to Forbidden Fromage, a series exploring cheesy taboos and prohibitions. Intern Johnisha Levi will look at everything from navigating kosher restrictions and hip hop MCs’ use of cheese and dairy as metaphors for illicit profit and sex to the paleo diet’s dairy prohibition. You’ll get a little history, religion, pop culture, science, and medicine along the way, as we cover thousands of years in the blink of some blog posts.


The relationship between Jews and hard cheese hasn’t always been an easy one. Think about the Eastern European Ashkenazi Jewish diet for a minute. Soft cheeses—namely cream cheese, sour cream, and cottage cheese—feature prominently in hallmark foods like blintzes, rugelach, kugel, and latkes (which were originally made with curd cheese, not potatoes). That’s no accident. It has everything to do with kashrut, or Jewish dietary law.

Kashrut is derived from the Torah as well as rabbinical interpretations. In this country, there are five major orthodox kosher certification agencies: Orthodox Union (“OU”), Star-K, OK Kosher Certification (“OK”), Kof-K Supervision, and the Chicago Rabbinical Council (“CRC”), collectively referred to as “The Big Five.” These agencies certify more than 80% of kosher food sold in the US. In addition to the Big Five, there are also thousands of separate rabbis and smaller agencies, including non-Orthodox authorities, offering kosher supervision. And of course Orthodox, Conservative, and Reform Judaism take different positions on what is acceptable to consume.

In other words, there is no simple and singular answer to what makes a cheese kosher. Here’s what Rabbi Gordimer, the Rabbinic Coordinator at the Orthodox Union and an authority on the koshering of dairy products has to say on the subject:

“The kashrut rules for cheese are among the most mysterious to the average kosher consumer. Even otherwise scholarly and erudite members of our community are often ‘in the dark” as to what makes cheese kosher.”

Similarly, the OU admits that “of all dairy products, kosher certification of cheese is the most difficult.”

Translation: This means I’m not even going to pretend to be an expert on the question of what makes a cheese kosher. I’ll leave that to the rabbinical authorities, as these determinations can be quite labyrinthine. Instead, I’m going to provide a framework for understanding the considerations and the conundrums facing those who keep kosher and who would like to have their cheese and eat it to.

Is the milk from a kosher species?

It would make sense in talking about cheese to start with a discussion of milk and where it comes from. In keeping with Jewish dietary law, it is permissible to partake of the meat and the milk of animals who have both cloven hooves and who chew their cuds. This means cows, sheep, and goats, but not pigs and camels.

But that isn’t the end of the story for milk. The Jewish legal code Shulcan Aruch also adds an extra layer of security, which makes a lot of sense in a historical context. Centuries ago, it was very common for farmers to mix the milk of different species together, meaning that there was the potential for milk from kosher species to combine with that of non-kosher species. Therefore, rabbis determined that Jews could only drink chalav Yisrael (“milk of Israel”), which is either milked by Jews themselves or milked by Gentiles supervised by Jews. Milk that did not meet either of these conditions was not considered fit under kosher law, and was declared chalav akum (“milk of star worshippers”).

Today, in the United States, we have very strict oversight of dairy production by the USDA. Dairies that don’t play by the rules face large fines and the prospect of losing their licenses. Because of the unlikelihood of contaminated milk, a leading rabbinical authority of the 20th century determined that government-regulated milk from commercial dairies, designated as chalav stam or “neutral milk,” can be safely consumed.

Is the cheese in question acid-set or rennet-set?

Now that we have milk covered, let’s move on to cheese and what kosher law dictates. The first question we must answer is whether we are talking about soft/acid-set cheeses or hard/rennet-set cheeses.

When vinegar, lemon juice, or lactic acid is used to coagulate milk, or milk is merely allowed to sour, the resultant cheese is not subject to the same level of supervision as their rennet-set counterparts. We’ll talk more about this below.

But what about rennet-set cheeses? Because rennet comes from the stomach of animals, which may or may not be kosher species, and which may or may not have been ritually slaughtered according to kosher law, this introduces a whole other set of issues. Which leads me to the question…

A rabbi in Israel “kashers,” or makes kosher, a batch of chicken livers. (Photo Credit: Avital Pinnick, CC)

A rabbi in Israel “kashers,” or makes kosher, a batch of chicken livers. (Photo Credit: Avital Pinnick | CC)

Is the rennet kosher?

This is indeed a complex question.

First, it is not enough for the rennet to derive from a cloven-hoof, cud-chewing species for it to pass muster. To be permissible under kashrut, the animal must also have been killed according to the law of ritual slaughter by a properly trained, observant shoctet, which includes taking measures to minimize pain, prevent cruelty to the animal, and remove forbidden fats and blood.

Assuming that these conditions are met, we move on to another question. One of the biggest injunctions of Jewish dietary law is the one prohibiting the mixing of meat and milk in the same meal, referred to as basar b’chalav. It derives from the injunction to “not cook a kid in the milk of its mother,” which appears in the Torah three times.

On its face, it would appear that adding animal rennet to milk would violate this prohibition.

But not so fast. Cheesemaking has merited a special dispensation, based on the fact that the rennet derives from dried tissue and does not really involve the mixing of meat and milk flavors. (“This is permitted in as much as it became like a mere piece of wood and there is not any meat juice in it.”) Although in some instances, kashrut allows for a minuscule amount of a non-kosher ingredient to be nullified (betel) such that it does not render an otherwise kosher product non-kosher, this is not the reason why adding rennet to milk isn’t considered mixing meat and milk. That’s because an ingredient (no matter how tiny an amount) that gives a product its actual form (as in the case of rennet giving form to cheese) can never be betel.

If the rennet in question has thus far cleared the meat and milk hurdle, next up is…

Has there been kosher supervision/administration of the rennet?

Certification agencies require rabbinical supervision to make sure that cheese is not gevinus akum, or—you guessed it—“star worshippers’ cheese,” and thus non-kosher and rabbinically prohibited. The rationale is similar to the one behind the chalav yisrael/chalav akum distinction: that is, to make sure that non-Jews haven’t contaminated the cheese by using rennet from an animal that was not ritually slaughtered.

But what about rennet that comes from a non-animal source? In the US, unlike Europe, the vast majority of cheese is made with microbial rennet, which is produced by growing proteins on microorganisms. Or how about cheese made from thistle rennet, such as some notable Portuguese cheeses? After all, these rennets take the animal entirely out of the rennet equation.

Even if microbial rennet is used, however, certifying agencies like the Orthodox Union (OU) will not recognize the cheese as kosher unless a mashgiach (supervising rabbinical kosher authority) either manually adds the rennet to the cheese vats or, in the case of larger operations, activates the automated rennet feeders. If this doesn’t happen, the cheese is gevinas akum, and therefore off limits.

In contrast, many agencies like the CRC are more lenient when it come to acid-set cheeses and will not prohibit them as gevinas akum if a rabbi is not the one to add the acid that coagulates the cheese. Ricotta cheese, which is a by-product of hard cheese, presents a bit of a tricky scenario, although it generally appears to be treated as a soft cheese.

What about cheesemaking equipment?

In addition to all of the considerations above, a vital part of ensuring that cheese is kosher also involves inspecting and cleaning any equipment to kasher it, or make sure that it is not contaminated by any non-kosher ingredients. This is particularly significant when a factory or facility produces both kosher and non-kosher products. For example, the OU notes that vats, cookers, brine tanks, and cheese cutters must all be kashered.


So that is the kosher conundrum in (more or less) a nut shell! Now that you have some foundation for understanding the various considerations that make a cheese kosher or non-kosher, next up is a look at some recent developments pertaining to the kosher availability of hard cheeses, including some news on Parmigiano Reggiano, kosher cheese Kickstarter campaigns, and a cheesemonger for the kosher crowd known as The Cheese Guy. Stay tuned!

Feature Photo Credit:“Grunge rubber stamp with text Kosher” by carmen2011 | Shutterstock

Johnisha Levi

Johnisha Levi is a Boston-area pastry cook and one of those very rare (think Pegasus) D.C. natives. If ithere's a documentary on food or true crime, chances are that she's seen it (or it's waiting in her Netflix queue). She's a culinary history nerd who is eager to spend her summer at culture learning more about cheese.