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The circled U indicates that this can of tuna is certified kosher by the Union of Orthodox Congregations.
The circled U indicates that this can of tuna is certified kosher by the Union of Orthodox Congregations.

The laws of kashrut (Hebrew כַּשְׁרוּת, Standard Hebrew kašrut) ("keeping kosher", Hebrew כֶּשֶׁר / כָּשֶׁר, Standard Hebrew kéšer / kášer) are the Jewish dietary laws. Food in accord with Jewish law is termed kosher, from the Hebrew term kasher (כשר), meaning "fit" (in this context, fit for human consumption). Food not in accord with Jewish law is termed treifah or treif (טרפה) ("torn"); the term originally referred to animals which had been slaughtered after being mortally wounded by wild beasts and therefore were not fit for human consumption. Among Sephardim it typically only refers to meat that is not kosher.

The basic laws of kashrut are in the Biblical book of Leviticus, their details explicated in the oral law (the Mishnah and the Talmud) and codified by the later rabbinical authorities.

There are actually varying degrees of Kashrut, with the ultimate degree shading into behavior more than just the food itself. For instance, meat which is not Kosher may be sold to the general public or used for pet food; however, milk and meat may not be combined together, even if the resulting mixture is to be discarded, let alone sold or fed to a pet.


Types of foods

See Kosher foods.

Foods are kosher when they meet all criteria that Jewish law applies to food. Invalidating characteristics may range from the presence of a mixture of meat and milk, to the use of produce from Israel that has not been tithed properly, or even the use of cooking utensils which had previously been used for non-kosher food.

Identification of kosher foods

Store-bought foods can be identified as kosher by the presence of a hechsher (pl. hechsherim), a graphical symbol that indicates that the food has been certified as kosher by a rabbinic authority. (This might be an individual rabbi, but is more often a rabbinic organization.) The most common symbol is the "": a U inside a circle, standing for the Union of Orthodox Congregations. Most rabbis and organizations, however, have their own certification mark, and the other symbols are too numerous to list.

The hechsherim of certain authorities are sometimes considered invalid by certain other authorities. A solitary K is sometimes used as a symbol for kashrut, but as this symbol cannot be trademarked (the method by which other symbols are protected from misuse), it does not indicate anything other than the fact that the company producing the food considers it to be kosher.

Another way to check the kashrut of an item is to read the list of ingredients; however, many observers of kashrut do not consider this to be sufficient. It can, however, identify obviously unkosher substances present in food.

Producers of food items and food additives can contact Jewish authorities to have their product deemed kosher. A committee will visit their facilities to inspect production methods and contents of the product and issue a certificate if everything is in order.

For various reasons, such as changes in manufacturing processes, previously kosher products can 'lose their hechsher'; a change in lubricating oil to one containing tallow, for instance. Often, these changes will be coordinated with the supervising rabbi or organization, to ensure that new packaging, which will not suggest any hechsher or kashrut, will be used for the new formulation. But in some cases, the supply of preprinted labels with the hechsher may still find its way onto the now nonkosher product; for such reasons, there is an active 'grapevine' among the Jewish community identifying which products are now questionable, as well as products which have become kosher but whose labels have yet to carry the hechsher. That 'grapevine' will also publicize situations where an unauthorized hechsher has appeared on a product either accidentally or deliberately.

Reasons for the Biblical dietary laws

There continues to be a debate on the purposes and meaning of the laws regarding Kashrut.

In Jewish philosophy it is recognised that of the 613 mitzvot, a large number cannot be explained rationally. They are categorised as "chukim", comprising such laws as the Red Heifer (Numeri 19). There are two points of view regarding these laws; one believes that these laws do have a reason but that the ultimate explanation for mitzvot is beyond the human intellect, while the other believes that these laws have no meaning other than to instill obedience.

"Some Jewish scholars have held that these dietary laws should simply be categorized with a group of laws that are considered irrational in that there is no particular explanation for their existence. The reason for this is that there are some of God's regulations for mankind that the human mind is not necessarily capable of understanding. Related to this is the idea that the dietary laws were given as a demonstration of God's authority and that man should obey without asking for a reason" (William H. Shea, Clean and Unclean Meats, Biblical Research Institute, December 1988).

This view, however, has been rejected by most classical and modern Jewish authorities, and by modern biblical scholars. For example, Maimonides holds that all the laws given by God have a reason, that we are permitted to seek out what these reasons may be, and that we should feel comfortable in knowing that rational reasons exist for all of God's laws in the Torah, even if we are not sure of what some of these reasons are. For Maimonides, the idea that God gave laws without any reason is anathema.

Ritual purity and holiness

According to the Biblical book of Leviticus, the purpose of the laws is related to ritual purity and holiness. Indeed, the Hebrew word for "holiness" is etymologically related to the Hebrew word for "distinction" or "separation." This idea is generally accepted by most Jews today, and by many modern biblical scholars. Cultural anthropologist Mary Douglas has written an important work on just how the Israelites may have used the idea of distinction as a way to create holiness. Her seminal work, Purity and Danger (1966), is still studied today. One theory widely accepted today is that the laws serve as a distinction between the Israelites and the non-Israelite nations of the world. Gordon Wenham writes:

"The laws reminded Israel what sort of behaviour was expected of her, that she had been chosen to be holy in an unclean world."

Similarly, the practice of Kashrut serves as a daily exercise in self-discipline and self-control, strengthening the practitioner's ability to choose other difficult paths. The ability to rationally curb one's most basic appetites can be seen as the prerequisite to living in a civilized society. Also, the aspects of Kosher slaughter which emphasize and incorporate the need to avoid unnecessary suffering of the animal remind the believer that having the power of life and death or to cause suffering, even to a farm animal born and bred to be eaten, is a serious responsibility rather than a pleasure to be sought after; and that to actually indulge in pleasure in the power to cause suffering, even in so common a practice as hunting, is to damage our own moral sensibilities. Modern psychology confirms that those who have no empathy for the suffering or death of animals are greatly at risk for also having no regard for suffering and death of their fellow humans.

The prohibition against eating the fruits of a tree for the first three years also represents a capacity for self-discipline and self-denial, as well as a lengthy period of appreciation for the bounty of God, prior to losing oneself in its enjoyment. Similarly, the requirement to tithe one's harvest, aside from the social justice aspect, serves as a reminder that this material wealth is not purely the result of one's own efforts, but represents a gift from God; and as such, to share the gift with one's fellows does not represent a real loss to oneself.

Symbolic purpose

During the first few centuries of the common era some philosophers held that the laws of kashrut were symbolic in character. In this view, kosher animals represent virtues, while non-kosher animals represent vices. The first indication of this view can be found in the 1st century BCE Letter of Aristeas (par. 145-148, 153). It later reappears in the writings of Philo of Alexandria, and in the writings of some of the early Church fathers.

This hypothesis has long since been rejected by most Jewish and Christian scholars. Modern biblical criticism also has found nothing to support this hypothesis, although the concept of the pig as a particularly 'unclean' animal persists among Jews.

Although the symbolic explanation for kashrut has been largely rejected, a number of authorities maintain that the laws are intended to promote ethical and moral behaviour. A recent authority who has reexamined the symbolic/ethical meaning of kashrut is Rabbi Samson Raphael Hirsch (Germany, 19th century).

To some degree, the prohibition on combining milk with meat represents a symbolic separation between death, represented by the flesh of a dead animal, and life, represented by the milk required to sustain a newborn creature. The often-quoted humane component to this law is also of symbolic value; the Torah prohibits us from 'seething the kid in its mother's milk', a practice cruel only in concept, which would not be understood as cruelty by either the kid or its mother and would not cause them additional suffering; but which could still potentially inflame a human's taste for ultimate power over those creatures who are weaker. Thus, Kashrut prohibits the practice itself, even if the resulting mixture is to be discarded.

Similarly, the prohibition against consuming carnivorous mammals and birds, 'loathsome crawling creatures', and scavengers, as well as the prohibition against consuming sick or diseased animals, would seem to rely, at least in part, on their perceived symbolic character.

Maintenance of a separate culture

Related to the concept of kashrut being one aspect of Judaism as a separate people is the practical outcome of maintaining a specific national diet, similar to the concept of reproductive isolation in speciation. Just as two species who can interbreed will merge into one, the theory of cultural evolution requires a degree of social separation for two cultures to remain distinct entities. The laws of Kashrut had the effect of preventing socialization and intermarriage with non-Jews, helping the Jewish community maintain its identity. Wenham writes that

"circumcision was a private matter, but the food laws made one's Jewish faith a public affair. Observance of the food laws was one of the outward marks of a practising Jew, and this in turn enhanced Jewish attachment to them as a reminder of their special status" (Gordon J. Wenham, "The Theology of Unclean Food," The Evangelical Quarterly 53, January March 1981, p.6-15).


The laws of kashrut were once thought to have been based on hygiene. It was believed by some that kosher animals were healthier to eat than non-kosher animals. It was also noted that the laws of purity (Leviticus 11–15) not only describe the difference between clean and unclean animals, but also describe other phenomena that appear to be related to health. For instance, glatt, the requirement that lungs be checked to be free of adhesions, would prevent consumption of animals who had been infected with tuberculosis; similarly, the ban on slaughtering of an unconscious animal would eliminate many sick and possibly infectious animals from being consumed. Such a rationale seems reasonable when considering the laws prohibiting the consumption of carrion birds or birds of prey (which are advantageous scavengers), as they may carry disease from the carrion they consume; shellfish, which as filter feeders can accumulate harmful parasites or toxins; or pork, which can harbor trichinosis if not properly cooked. Thus, it was natural for many to assume that all the laws of kashrut were merely hygienic in intent and origin. One of the rabbinical authorities that mention the hygiene hypothesis is Maimonides (in his Guide for the Perplexed).

For a number of reasons, however, this idea has fallen out of favor among biblical scholars. Fruits and vegetables may be eaten without prohibition even though there are many poisonous herbs, seeds, berries and fruits. Additionally, this hypothesis does not explain other parts of the Jewish dietary laws; for instance forbidding the consumption of fish without true scales, such as sharks, fruit from trees which are less than four years old, or residual blood in meat.

This is not to say that there could be no connection between the priestly laws of kashrut and hygiene. As in the dietary codes of many societies, it only makes sense that, over time, hygiene would likely play some role in the development of the dietary laws of Leviticus. The process of cultural evolution would eventually favor such a society over one that persisted in consumption of unhealthy foods.

Other reasons

There is also the suggestion of a practical aspect to some of the laws of Kashrut; for instance, the pig would not be a wise choice of domestic animal for a nation which was, at the time, a nomadic desert tribe.

The laws of Kashrut also conform to a general rule that human societies tend to separate food animals from companion animals, whether pets or working animals . For instance, where dogs are kept as pets, they are not eaten; in most countries, where horses are used as draft animals they are not eaten, but in countries where oxen and cows are used as draft animals, such as India, they are not eaten.

Like the laws for the slaughter of animals, laws against shellfish could actually be for the good of the creature. There is no painless method for the preparation of "bottom feeding" lobster and crab.

In probability, there are multiple reasons for the laws of Kashrut, with each law serving one or more than one purpose.

How kashrut is viewed by Judaism today

Orthodox Judaism and Conservative Judaism hold that Jews should follow the laws of kashrut. Reform Judaism and Reconstructionist Judaism hold that these laws are no longer binding. Most Jews in Reform Judaism have considered these laws a hindrance, rather than a facilitator, of piety; this is still the mainstream Reform position. Some parts of the Reform community have begun to move towards a more traditional position. This tradition-leaning faction agrees with mainstream Reform that the rules concerning kashrut are no longer binding, but holds that keeping kosher is an important way for people to bring holiness into their lives. Thus Jews are encouraged to consider adopting some or all of the rules of kashrut on a voluntary basis. The Reconstructionist movement advocates that its members accept some of the rules of kashrut, but does so in a non-binding fashion; their stance on kashrut is the same as the tradition-leaning wing of Reform. The different movements' positions on kashrut are reflective of their broader perspectives on Jewish law as a whole.

Many Jews who do not meet the complete requirements of Kashrut nevertheless maintain some subset of the laws; for instance, abstaining from pork or shellfish. Many Jews will likewise avoid drinking milk with a meat dish, without knowing why doing so seems alien. Similarly, many keep a degree of Kashrut at home while having no problems eating in a non-kosher restaurant.

In English, the term kosher is frequently used in a metaphorical sense to mean "acceptable" or "approved", which is its conventional meaning in Hebrew. It is also part of some common product names. For example, "kosher salt" (technically "kashering salt") is a form of salt which has irregularly-shaped crystals, making it particularly suitable for preparing meat in accordance with Kashrut law because the increased surface area of the crystals absorbs blood more effectively. Likewise, a "kosher pickle" is a particular style of pickle that originated in Eastern European kosher delis with a distinctive flavor.

Consumer-protection laws in many jurisdictions prohibit use of the term "kosher" unless it is shown to conform to Jewish dietary laws, but this will be defined differently for different jurisdictions and different situations. For example, in some places the law may require that a rabbi certify the kashrut, and in others it is sufficient that the manufacturer believes the product to be kosher. Most packaged food products that are labelled "kosher" will therefore have some level of certification of compliance with the laws of kashrut, though individuals must determine if that level is adequate for themselves.


Since there are few laws of Kashrut restricting the consumption of plant products (except for fruits, harvested from a tree, less than three years after its planting -- which isn't applicable outside of the Land of Israel), it follows that a truly vegetarian meal would be inherently Kosher (as long as the milk and wine are supervised and the utensils are never used for meat or unsupervised milk). In practice, however, those who rigorously follow the laws of Kashrut do not automatically regard all restaurants or prepared or canned food which claim to be vegetarian as Kosher, due to some doubt as to whether the degree of supervision maintained is in all cases sufficiently stringent. Many vegetarian restaurants and producers of vegetarian foods do acquire a hechsher, certifying that a Rabbinical organization has approved of them as Kosher, since this requires no additional care on their part if they are truly vegetarian.

The situation is not always reversible, however; although parve food can contain neither meat nor dairy, that label on a product cannot be always used by vegetarians as a reliable indication, since Kashrut considers fish to be parve. However, in practice it is rare to find fish products in parve foods; moreover, because of potential issues of mixing meat and fish (see Fish and seafood) many Kashrut supervising authorities specifically indicate the presence of fish products when they are found in parve foods.

People who have specific dietary needs should be aware that their standards for certain concepts may differ from the halachic standards for similar concepts.

  • Many coffee creamers currently sold in the United States are labeled as "non-dairy", yet also have a "D" alongside their hechsher, which indicates a dairy status. This is because of an ingredient (usually sodium caseinate) which is derived from milk. The rabbis consider it to be close enough to milk that it cannot be mixed with meat, but the US government considers it to lack the nutritional value of milk. Such products are also unsuitable for vegans and other strict dairy abstainers.
  • On the other hand, kashrut does recognize some processes as capable of converting a meat or dairy product into a parve one. For example, rennet is made from stomach linings, yet is acceptable for making kosher cheese, but such cheeses might not be acceptable to some vegetarians, who would eat only cheese made from a vegetarian rennin. The same applies to kosher gelatin which in some cases is an animal product, despite its parve status.
  • Kashrut has procedures by which equipment can be cleaned of its previous non-kosher use, but that might be inadequate for vegetarians, or other religions, or others.
  • For example, dairy manufacturing equipment can be cleaned well enough that the rabbis will grant parve status to products manufactured afterward. Nevertheless, someone with a strong allergic sensitivity to dairy products might still react to the dairy residue, and that is why some products will have a "milk" warning on a product which is legitimately parve.

Genesis 1:29 states "And God said: Behold, I have given you every herb yielding seed which is upon the face of all the earth, and every tree that has seed-yielding fruit - to you it shall be for food." According to many classical Jewish Bible commentators, this means that God's original plan was for mankind to be vegetarian, and that God later gave permission for man to eat meat because of man's weak nature. However, others argue that people may eat animals because God gave Eve and Adam dominion over them. Few prominent rabbis have been vegetarian, among them the first Chief Rabbi of pre-state Israel, Abraham Isaac Kook.

Halakha strongly encourages the eating of meat at the Sabbath and Festival meals, and some Orthodox Jews who are otherwise vegetarian will nevertheless consume meat at these meals. Many Orthodox authorities have ruled that it is forbidden for an individual to become a vegetarian if they do so because they believe in animal rights; however, they have also ruled that vegetarianism is allowed for pragmatic reasons (if kosher meat is expensive or hard to come by in their area), health concerns, or for reasons of personal taste (if someone finds meat unpalatable).

Kashrut and animal welfare

The practice of kosher slaughter emphasizes the sharpness of the knife and the accuracy and precision of the skill of the shochet, in order to slit the jugular of the animal with an absolute minimum of pain and suffering. In general, over the years authorities have ruled that any unnecessary suffering by the animal can render otherwise kosher meat traife. Nevertheless, the method of slaughter used in strict adherence to Jewish law has been criticized as being inhumane by a small number of animal rights organizations, in particular because animals are killed without the use of anesthesia, often administered to beef by firing a bolt into the brain or by electric shock to the head. (Traditional kashrut would often not allow for anesthesia, as it may severely injure the animal before it is slaughtered, rendering it Treifa, and because Kashrut prohibits slaughter of an unconscious animal, which might be diseased.) This has resulted in several restrictions or even an outright ban on kosher meat in a number of countries, sometimes encompassing related practices such as Muslim halal slaughter, though other countries grant ritualistic slaughter such as kashrut special exemption from the relevant regulations. However, some bans were in place before animal rights had become a general public concern.

Some animal rights groups such as People for the Ethical Treatment of Animals object to kosher slaughter, claiming it can take several minutes for the animal to die and can often cause immense suffering. Jewish groups point to studies showing that the technique is no more painful than conventional techniques, and in most cases quicker and less painful; the emphasis on flawless procedure and tools contrasts with the often sloppy production line methodology of the slaughterhouse resulting in failure to stun the animal, as often described by animal rights advocates in other contexts. However, the conclusions of these studies are sometimes rejected by animal rights advocates. In addition, there are campaigns to have the practice of ritualistic slaughter globally banned.

In some ways, modern slaughtering practices and kashrut practices clash, although both may have good intentions with respect to hygiene and animal welfare; for instance, kashrut prohibits slaughter of an unconscious animal, for reasons of avoiding consumption of a diseased animal as well as the possibility of inhumane means of anesthesia, and relies on the skill of the shochet and the sharpness of the knife to slit the jugular as painlessly as possible. On the other hand, for reasons of hygiene, modern slaughterhouse regulations prohibit the carcass of an animal from falling into the blood of another, so that animals are often suspended by a leg before being slaughtered; they would normally be stunned by a blow to the head to prevent suffering in this process, but the prohibition of slaughter of an unconscious animal prevents this for kosher slaughter. Of course, other, more humane, methods of supporting the carcass of the animal after it is slaughtered are available, but since they are more expensive and not routinely used for nonkosher slaughter, slaughterhouses are reluctant to adopt them, and when they do often greatly raise the price of the meat to compensate for the nonstandard technique.

Many Jewish organizations suspect that covert anti-Semitism may also be an influence behind the efforts to ban kosher meat, partly because of a distinct anti-Semitic element among the opponents of ritualistic slaughter, partly because of the age of some bans.

See also

Further reading

  • James M. Lebeau, The Jewish Dietary Laws: Sanctify Life, United Synagogue of Conservative Judaism, New York, 1983
  • Samuel Dresner, Seymour Siegel and David Pollock The Jewish Dietary Laws, United Synagogue, New York, 1982
  • Isidore Grunfeld, The Jewish Dietary Laws, London: Soncino, 1972
  • Isaac Klein, A Guide to Jewish Religious Practice, JTSA, 1992
  • Shechita: Religious, Historical and Scientific Perspectives, Munk, Feldheim Publishers, New York, 1976

External links

Last updated: 09-12-2005 02:39:13