Kashrut

Kashrut (also kashruth or kashrus, כַּשְרוּת) refers to Jewish dietary laws. Food in accord with halakha (Jewish law) is termed kosher in English, from the Hebrew term kashér, meaning "fit" (in this context, fit for consumption by Jews according to traditional Jewish law). Jews may not consume non-kosher food (but there are no restrictions for non-dietary use, for example, injection of insulin of porcine origin).

Food that is not in accord with Jewish law is called treif, (טרייף or treyf (Hebrew טְרֵפָה). Treif meat is meat from a non-kosher animal or a kosher animal that has not been properly slaughtered according to Jewish law.

Many of the basic laws of kashrut are in the Torah's Book of Leviticus, with their details set down in the oral law (the Mishnah and the Talmud) and codified by the Shulchan Aruch and later rabbinical authorities. Many varied reasons have been offered for these laws, ranging from philosophical and ritualistic, to practical and hygienic.

By extension, the word kosher means legitimate, acceptable, permissible, genuine or authentic, in a broader sense.

The Islamic equivalent for Muslims is halal, which overlaps with kosher, but is not identical.

Principles
The laws of kashrut derive from various passages in the Torah, and are numerous and complex, but the key principles are as follows:
 * Only meat from particular species is permissible:
 * Only mammals that chew their cud (ruminate) and have cloven hooves are kosher.
 * Birds must fit certain criteria; birds of prey are not kosher. There must be an established tradition that a bird is kosher before it can be consumed.
 * Fish must have fins and scales to be kosher. Shellfish and non-fish water fauna are not kosher.
 * Insects are not kosher, except for certain species of kosher locust (unrecognized in most communities).
 * Meat and milk (or derivatives) cannot be mixed, i.e. meat and dairy products are not served at the same meal, served or cooked in the same utensils, or stored together. Observant Jews have separate sets of dishes for meat and milk.
 * Mammals and fowl must be slaughtered in specific fashion: slaughter is done by a trained individual (a shochet) using a special method of slaughter, shechita. Among other features, shechita slaughter severs the jugular vein, carotid artery, esophagus and trachea in a single cut with an unserrated, sharp knife. Failure of one of these criteria renders the meat of the animal unsuitable. The body must be checked post-slaughter so as to be certain that the animal had no medical condition or defect that would have caused it to die of its own accord.
 * Blood must be removed as much as possible through the "kashering process. However, if a minute amount remains after it is halachically schected (slaughtered) and salted and cooked, it is permissible.  Removing the blood is often accomplished through soaking and salting the meat, by broiling it, or grilling it over an open flame.
 * Utensils used for non-kosher foods are rendered non-kosher, and will transfer that non-kosher status to kosher foods. Some utensils, depending on the material they are made from, can be made kosher again by immersion in boiling water.
 * Food that is prepared by Jews in a manner which violates the Shabbat (Sabbath) may not be eaten.
 * Passover has special dietary rules, the most important of which is the prohibition on eating leavened bread (chametz). Utensils used in preparing and serving chametz are also forbidden on Passover. Observant Jews traditionally have separate sets of meat and dairy utensils for Passover use only.
 * Certain foods must have been prepared in whole or in part by Jews, including:
 * Wine
 * Certain cooked foods (bishul akum)
 * Cheese (gvinas akum)
 * According to many: certain dairy products (Hebrew: חלב ישראל cholov Yisroel "milk of Israel")
 * According to some: bread (under certain circumstances) (Pat Yisrael)
 * Biblical rules control the use of agriculture produce: for produce grown in the Land of Israel a modified version of the Biblical tithes must be applied, including Terumat HaMaaser, Maaser Rishon, Maaser Sheni, and Maaser Ani (untithed produce is called Tevel); the fruit of the first three years of a tree’s growth or replanting are forbidden for eating or any other use as Orlah ; produce grown in the Land of Israel on the seventh year is Shviis, and unless managed carefully is forbidden as a violation of the Shmita (Sabbatical Year).

The following rules of kashrut are not universally observed:
 * The rule against eating new grain (yoshon) outside the Land of Israel
 * In addition, some groups follow various eating restrictions on Passover which go beyond the rules of kashrut, such as the eating of gebrochts or garlic.

Conservative Judaism follows a number of leniencies, including:
 * Permitting kashering with less than boiling water under certain circumstances (which permits a dishwasher to be used for meat and dairy dishes, although not at the same time, provided the dishwasher will not absorb particles of the food)
 * Classifying various chemical additives derived from non-kosher meat products as nonfood and permissible (for example, permitting rennet from cow's stomachs to be used in cheese and horse-hoof gelatin in foods)
 * A variety of additional details.

Although Reconstructionist Judaism and some perspectives within Reform Judaism encourage individuals to follow some or all aspects of the kashrut rules required by the more traditional branches, these branches do not require their observance and do not maintain their own sets of required rules.

Types of foods
Foods are kosher when they meet all criteria that Jewish law applies to food and drinks. 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 (plural hechsherim), a graphical symbol that indicates that the food has been certified as kosher by a rabbinical authority. (This might be an individual rabbi, but is more often a rabbinic organization.) One of the most common symbols in the United States is the "OU", a U inside a circle, standing for the Union of Orthodox Congregations (or "Orthodox Union"). Many rabbis and organizations, however, have their own certification mark, and the other symbols are too numerous to list.

Many kashrut certification symbols are accompanied by additional letters or words to indicate the category of the food. In common usage is "D" for Dairy, "M" for Meat or poultry, "Pareve" for food that is neither meat nor dairy, "Fish" for foods containing such, and "P" for Passover (not to be confused with Pareve). Note that many foods meet the US FDA standard for "Non-Dairy" while they do not meet the Jewish standard for "Pareve" and are labeled with the "D" next to the kosher symbol.

A single K is sometimes used as a symbol for kosher, but as a letter cannot be trademarked (the method by which other symbols are protected from misuse) in many countries, it only indicates that the company producing the food claims it is kosher.

The hechsheirim of certain authorities are sometimes considered invalid by certain other authorities.

It is not sufficient to read the list of ingredients on a product label in order to determine a food's kosher status, as many things are not included in this list, such as pan lubricants and release agents (which may be derived from lard), flavorings ("natural flavorings" are more likely to be derived from non-kosher substances than others) and others. Reading the label can, however, identify obviously unkosher ingredients.

Producers of foods and food additives can contact Jewish authorities to have their products certified as kosher: a committee will visit their facilities to inspect production methods and contents, and issue a certificate if everything is in order. In many cases constant supervision is required.

For various reasons, such as changes in manufacturing processes, products which were kosher may cease to be so; for example, a kosher lubricating oil may be replaced by one containing tallow. Such changes are often coordinated with the supervising rabbi or organization to ensure that new packaging, which will not suggest any hechsher or kashrut, is used for the new formulation. But in some cases existing stocks of preprinted labels with the hechsher may continue to be used on the now non-kosher product; for such reasons, there is an active "grapevine" among the Jewish community, as well as newspapers and periodicals, identifying which products are now questionable, as well as products which have become kosher but whose labels have yet to carry the hechsher.

Attempts to explain the laws of kashrut
There continues to be a debate among various theories about the purposes and meaning of the laws regarding kashrut.

Jewish religious explanations
Traditional Jewish philosophy divides the 613 mitzvot into mishpatim (laws which can be explained rationally) and chukim (laws which cannot be explained rationally). Those categorized as chukim include such laws as the Red Heifer (Numbers 19). There are three basic points of view regarding these laws:
 * One view is that these laws were ordained for the protection and health of God's people in a time where basic hygiene was not yet understood. For example, carrion was against Jewish law. As we know today many such animals are ridden with diseases as they begin to decompose. Also, shellfish can be easily contaminated with hepatitis and other diseases if they are not cared for properly, these were also against Jewish law.
 * A second view holds that these laws do have a reason, but it is not understood because the ultimate explanation for mitzvot is beyond the human intellect; and
 * A third view holds 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.

This last view, however, has been rejected by most classical and modern Jewish authorities. For example, Maimonides holds that we are permitted to seek out reasons for the laws of the Torah.

There is also the view that the obedience to the laws of kashrut are a necessary precondition for a Jew to be able to reach his utmost spiritual capacity. According to this understanding, the laws are meant to say that one must first have obedience in his base, animalistic sectors of life in order to achieve obedience and spirituality in the more lofty pursuits of Judaism.

Hasidic view of the laws of kashrut
According to the teachings of Hasidism, when a Jew manipulates any object for a holy reason (which includes eating, if it is done with a proper intention&mdash;to provide strength to follow laws of Torah), he releases "sparks of Holiness" which are found in every object. These "sparks" are actually channels of connection with the Divinity, and their "activation" allows the drawing of the Divine Presence into the physical world. 

However, there are some types of animals, whose products are not applicable for performance of commandments, because the "sparks of holiness" cannot be released from their matter. Therefore, we are provided with "signs" of the animals whose sparks can be released. These signs are split hooves (hooves symbolize connection with the material world which, however, is not so complete as to lose connection with the spiritual world), and rechewing of food (food symbolizes Torah or in more general terms, holiness; rechewing of food symbolizes ability to penetrate deeper into some holy concepts or penetrate deeped into holiness, as is necessary to separate sparks from their matter). For fish (which symbolize sages), these signs are scales (protection from water, which is a symbol of intellectual influence) and fins (that gives fish ability to move in water better, which symbolizes ability to move from one area of Torah or holiness to another).

It must be noted that these signs are not the causes of these animals not being kosher (so, according to Talmud, if a camel is born with completely split hooves, it does not become kosher), they are merely signs that alert us to spiritual characteristics of these animals' products (namely, whether it's possible to activate their "sparks of Divinity") which cannot be seen from the physical perspective.

Ritual purity and holiness
Cultural anthropologist Mary Douglas has written on just how the Israelites may have used the idea of distinction as a way to create holiness. Her work, Purity and Danger (1966), is still studied today. One theory 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, according to this theory, 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, Jews consider the aspects of kosher slaughter which emphasize and incorporate the need to avoid unnecessary suffering of the animal a reminder to 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.

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 anyone, even 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 BC 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 'seething the kid (goat, sheep, calf) 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
According to Christian theologian Gordon J. Wenham, the purpose of kashrut is to help maintain Jews as a separate people. 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."

Hygiene
There have been attempts to provide empirical support for the view that kashrut laws have hygienic benefits.

It was believed by some people 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 and swordfish (though see kosher foods for discussion on kashrut of swordfish), fruit from trees which are less than four years old, or residual blood in meat.

In 1953, Dr. David I. Macht, a Johns Hopkins University researcher, performed experiments on many different kinds of animals and fish, and concluded that the concentration of zoological toxins of the "unclean" animals was higher than that of the "clean" animals, and that the correlation with the description in Leviticus was 100%. In addition, Dr. Macht's research indicated harmful physiological effects of mixtures of meat and milk, and ritually slaughtered meat appeared to be lower in toxins than meat from other sources The conclusions of the paper published in Johns Hopkins Bulletin of the History of Medicine were challenged in a paper by biologists written at the request of a Seventh-day Adventist Church publication.

Other reasons
Others have hypothesized that there are multiple reasons for the laws of kashrut, with each law serving one or more than one purpose.

Sociologist Marvin Harris has proposed that the Jewish prohibition of pork results from the fact that in arid countries such as Israel, it is possible to raise pork only by feeding it grains that are also eaten by people, since the pigs cannot forage in nonexistent forests. In bad harvest years, there would be a social conflict between those who could afford to raise and eat pork and those who would be at risk of starvation due to the scarcity of edible grains. Thus, in the interest of social survival, the prohibition entered the Jewish religion. Harris in Cows, Pigs, Wars and Witches cites worldwide examples of similar ecologically determined religious practices, including other prohibitions of pork for similar reasons. According to Harris, pork requires too much salt to guarantee the elimination of the carcass liquids due to high fat content. The reverse process of washing out the preserving salt when it came to eating the meat also made it difficult to justify. This same reason would apply to many other forbidden foods either because salting preservation was impossible or because the salting process was not reversible.

U.S. laws regarding use of the word 'kosher'
In some states in the U.S. (Arkansas, California, Connecticut, Illinois, Kentucky, Louisiana, Maryland, Massachusetts, Minnesota, Missouri, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Texas, and Virginia, as well as local ordinances in two counties in Florida and the Independent City of Baltimore), statutes defined "kosher" and made it a crime to sell a product which was called "kosher" if, in general, it was not processed in accordance with the Jewish religion. Earlier court decisions upheld some of these laws. Courts have since determined that because this represents a state establishment of a religious practice, when such laws have been challenged, they have been struck down. Those who oppose the above rulings argue that kashrut is simply a set of standards for food preparation, nothing more; there is no difference between labelling something "low sodium", "high-fiber", "pasteurized", "kosher", "calcium-enriched", or "contains no cholesterol".


 * Baltimore's City ordinance creating a kosher law was found to be unconstitutional: Barghout v. Bureau of Kosher Meat & Food Control, 66 F. 3d 1337 (4th Cir. 1995).
 * New Jersey's Kosher laws were found to violate the Establishment clauses of both the New Jersey state constitution and the First Amendment: Perretti v. Ran-Dav's County Kosher Inc., 289 N.J. Super 618, 674 A. 2d 647 (Superior Ct. Appellate Div 1996). The opinion was affirmed by the New Jersey Supreme Court in which it found that the State's use of "Orthodox Jewish law" as a basis for the definition of kosher was an adoption of substantive religious standards which violated the State and Federal constitutions. 129 N.J. 155.  The State's response was to create a new law which avoids any definition of a standard for what is or is not considered kosher. Instead, establishments which claim to be kosher must publicize what they mean by that, and the State will check to ensure that this standard is adhered to. For example, kosher restaurants must display a poster (provided by the Kosher Food Enforcement Bureau) on which they display the name of their rabbinic certifier, how often he inspects the place, whether or not he requires all ingredients to be kosher-supervised, and so on. In this manner, government enforcement becomes a consumer-protection issue, and avoids the problems of advancing any particular religious view.
 * The United States Court of Appeals for the Second Circuit found that the challenged provisions of New York's Kosher Fraud law "on their face violate the Establishment Clause because they excessively entangle the State of New York with religion and impermissibly advance Orthodox Judaism." Commack Self-Serv. Kosher Meats, Inc. v. Weiss, 294 F.3d 415 (2d Cir. 2002), 45 ATLA L. Rep. 282 (October 2002). The Supreme Court refused to hear the case, and denied certiorari (123 S. Ct. 1250 (mem.) (2003)). The statute has since been revised and a new statute, The McKinney's Agriculture and Markets Law Sec. 201-a has since been passed.

In contemporary Judaism
Orthodox Judaism and Conservative Judaism hold that Jews should follow the laws of kashrut as a matter of religious obligation. Reform Judaism and Reconstructionist Judaism hold that these laws are no longer binding. Historically, Reform Judaism actively opposed kashrut as an archaism inhibiting the integration of Jews in the general society. More recently, some parts of the Reform community have begun to explore the option of a more traditional approach. This tradition-leaning faction agrees with mainstream Reform that the rules concerning kashrut are not obligatory, but believe that Jews should consider keeping kosher because it is a valuable 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.

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. Similarly, many keep a degree of kashrut at home while having no problems eating in a non-kosher restaurant, or will follow leniencies when eating out that they would not follow at home.

In common vernacular
In English and Hebrew, the term kosher is frequently used in a metaphorical sense to mean "fitting" or "correct". This is also its conventional meaning in Hebrew. For example, a mezuzah, a Tefillin, a Torah scroll or even an etrog can be kosher (if it is fit for ritual use) or non-kosher (if it is unfit for ritual use), but their "kashrut" has nothing to do with food.

It is also part of some common product names. For example, "kosher salt" (technically "koshering 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" dill pickle is usually not kosher in the sense that it was prepared under rabbinical supervision, which would ensure that no utensil in contact with the pickles had been in contact with food that was not kosher. Rather, it is a pickle made in the traditional manner of Jewish New York City pickle makers with generous addition of garlic to the brine. This is the same reason why the usage of the term "kosher-style" became frequently used in the food industry, from delis to restaurants, and even street vendors.

Protection of the term
Consumer-protection laws in many jurisdictions prohibit use of the term "kosher" unless it is shown to conform to Jewish dietary laws, however this will be defined differently for different jurisdictions and 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. More detail on the "legal" usage of the term "kosher" can be found in the section above entiled "U.S. Laws regarding use of the word Kosher"

Israeli usage of the term
A new movement in Israel demands that an establishment — a grocery store or restaurant — will only be considered fully kosher if its employees are paid a decent wage and treated fairly, and there is access for the handicapped. This will require a second certificate of kashrut in addition to the standard one.

Ethical eating
The translation of the root כ ש ר (K-Sh-R, Kaf-Shin-Resh) when used in this context is generally accepted to be about the "fitness" or "kosherness" of the food for consumption. There are two major strains of thought on alternative ways that "kashrut" should be practiced in order to more broadly categorize food as fit for consumption. In addition to these two major strains of thought, some, especially in the United Kingdom, have taken the fitness of the food they eat as directly dependent on how ethically it was produced, specifically in relation to its impact on the world and its people. For instance only Fairtrade teas and coffees are served in some synagogues and community centers and eggs used are organic or free range.

Vegetarianism
Since there are few laws of kashrut restricting the consumption of plant products, many people assume that a strictly vegetarian meal would usually be inherently kosher. In practice, however, those who 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 the likelihood that the utensils were used previously with non-kosher products, as well as the concern that there may be non-kosher ingredients mixed in, which, although they may still be considered vegetarian, would make the food not kosher. Additionally, kashrut does provide special requirements for some vegetarian products, such as wine and bread.

Many vegetarian restaurants and producers of vegetarian foods do in fact acquire a hechsher, certifying that a Rabbinical organization has approved their products as being kosher. In addition to the above concerns, the hechsher will usually certify that certain suspect vegetables have been checked for insect infestation, and that steps have been taken to ensure that any cooked food meets the requirements of bishul Yisrael.

Most vegetables, particularly leafy vegetables (lettuce, cabbage, parsley, dill, etc.), must be thoroughly checked for insect infestation (see link below for video instruction on proper checking procedure from the OU). The consumption of insects involves between three and six violations of Torah law; so, according to Jewish Law, it is a greater sin than the consumption of pork. The proper procedure for inspecting and cleaning will vary by species, growing conditions, and the views of any particular rabbi.

The situation is not always reversible, however; although pareve 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 parev. Because of potential issues of mixing meat and fish (see Fish and seafood) some kashrut supervising authorities specifically indicate the presence of fish products when they are found in pareve 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 categorize it as dairy that 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 pareve one. For example, rennet is sometimes 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 rennet. The same applies to kosher gelatin which in some cases is an animal product, despite its parev 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. For example, dairy manufacturing equipment can be cleaned well enough that the rabbis will grant parev 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 parev.

Kashrut and animal welfare
Kashrut prohibits slaughter of an unconscious animal to avoid consumption of a diseased animal and also to negate the possibility of inhumane means of anesthesia. It relies on the skill of the shochet and the sharpness of the knife to slit the jugular as painlessly as possible.

Some animal rights groups object to some forms of 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 much 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 usually rejected by animal rights advocates. In addition, there are campaigns to have the practice of ritualistic slaughter globally banned.

Specific kashrut laws counter some of the rituals of ancient times, such as eating only one leg of a live animal so that people would not have to deal with eating the entire animal at one time (Babylonian Talmud Sanhedrin 56b); this law applies even to non-Jews and is part of the Noahide Laws. Some authorities have ruled that any unnecessary suffering by the animal can render otherwise kosher meat traife.

Kashrut and working conditions
Heksher Tzedek, a proposed certification that food was produced under safe and just working conditions, has been endorsed by the Rabbinical Assembly, the national association of Conservative rabbis, but specific requirements for implementation of certification remain under development. It would be an additional certification, not a replacement for kosher certification.

One counterargument is that an entity certifying Kashrut should remain outside political issues of labor. In particular, the laws of labor, as dictated by Torah, are being addressed by the laws of the United States of America as noted by Rabbi A. Zeilingold in an interview. The Government of the United States of America provides many means for individuals to report and prosecute employers that violate the law, however this information is never made transparent to consumers through certification or product markings, such as Kosher labeling.

Some questions posed by critics remain open in the matter of the Tzedek Heksher:  If there is an accident in a meat plant certified by the Heksher Tzedek as safe, will the rabbinical group that certified the plant be liable to a lawsuit? How are the people certifying the Heksher Tzedek going to oversee that a plant is fair to workers or not? How are the people certifying the Heksher Tzedek determine what is fair or not fair in matters of labor? 

Resources on keeping kosher

 * Online resource for keeping Kosher and becoming Kosher certified - The Orthodox Union
 * Questions and Answers about specific food products and kashrut in general
 * Guide to keeping kosher
 * International Kosher Symbols and Kosher Food Guidance
 * Kashrut Alerts
 * BC Kosher's Website
 * Kosher Certification
 * The Star K's website
 * The O-K's website
 * A useful guide to the issues of kashrus

On ritual slaughter

 * Shehitah- The Laws
 * About Shechita: The Method of Animal Slaughter
 * Controversy over recent PETA complaint
 * Studies on pain during slaughter
 * Conservative Judaism viewpoints on which methods should be considered kosher
 * What limit religious freedom? The ban on kosher meat in Switzerland
 * Proposed British ban on kosher and halal meat
 * Campaign against all ritual slaughter
 * Procedures and equipment designed for humane ritual slaughter by Prof. Temple Grandin, a world renowned professional designer of humane livestock facilities.

Miscellaneous

 * About Kosher Food: Menus and Recipes
 * Economics of NaCl: Salt made the world go round Bloch, David:.
 * Kosher.com
 * Traditional Kosher foods recipes
 * The Torah and vegetarianism
 * Second Jewish Encyclopaedia's excerpt on kashrut and Jewish dietary laws
 * Video tutorial on checking some of the most problematic vegetables for insects (not kosher) from the Orthodox Union
 * Kashrut certification agencies (partial list) from around the world, and their symbols which are found on all food that they have been deemed kosher.

Kašrut Kashrut Jüdische Speisegesetze Cashrut Koŝera Cacheroute Kóxer Kosher Casherut כשרות Kosher Kasjroet カシュルート Kasjrut Kasjrút Koszerność Cashrut Кашрут Kashrut Kašrut Kosher Kosher Kaşer Кошерний כשרות 符合教規的食物 (猶太教)