Kosher foods



Kosher foods are those that conform to Jewish law. 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. For an in-depth discussion of this tradition, see kashrut.

Meat
Modern halakha (Jewish law) on kashrut classifies the flesh of both mammals and birds as "meat"; fish are considered to be parve (also spelled parev, pareve; Yiddish: פארעוו parev), neither meat nor dairy.

Mammals: 11:3–11:8
The dietary laws are given in Leviticus 11: "And the Lord spoke to Moses and to Aaron, saying: "speak to the children of Israel, saying, 'These are the living things which you may eat among all the animals that are on the earth.'" (Leviticus 11:1–11:2). Leviticus 11:3 sets down that Jews may eat animals (some translations use "beasts") that have cloven hooves and chew their cud, and Leviticus 11:4 explicitly prohibited the consumption of animals that do not have these characteristics, designating them "unclean to you." Four mammals are specifically prohibited:

""But this is what you shall not eat from among those that bring up their cud or that have split hooves; the camel, for it brings up its cud, but its hoof is not split&mdash; it is unclean to you; and the hyrax, for it brings up its cud, but its hoof is not split&mdash; it is unclean to you;and the hare, for it brings up its cud, but its hoof is not split&mdash; it is unclean to you; and the pig, for its hoof is split and its hoof is completely separated, yet it does not chew its cud&mdash; it is unclean to you. You shall not eat of their flesh nor shall you touch their carcass&mdash; they are unclean to you.""

- Leviticus 11:4-8

The identification of the above animals and other issues relating to this topic is the subject of much debate. Recently, Natan Slifkin published a book, titled "The Camel, the Hare, and the Hyrax" on the topic..

All kosher mammals, therefore, are even-toed ungulates and herbivores in the suborder Ruminantia, including several common domesticated animals and many wild animals. Kosher animals include the following:
 * Bovines (family Bovidae) (cattle (cows), goats, sheep, and antelope)
 * Musk deer (family Moschidae)
 * Deer (family Cervidae)
 * Giraffes and okapis (family Giraffidae)
 * Pronghorns (family Antilocapridae)

Because of the rule saying that Kosher food has to have parted hoofs, chew cud and eat vegetation, those that prey on other animals will be included as foods unclean.

Leviticus 11:8 commands the Jews that, "of their flesh [of other animals] you shall not eat, and of their carcass you shall not touch." The following verse, Leviticus 11:9, goes on to address seafood.

Seafood: 11:9-12
In Leviticus 11:9, seafood ("all that are in the waters") is addressed. As was done for mammals, two criteria are given for fish also: whatever has "fins and scales" may be eaten. The following verses describe seafood that does not have fins and scales as "an abomination," and commands the Israelites, "of their flesh you shall not eat, and their carcasses you shall detest."

For a fish to be kosher, the fins must be translucent and the scales easily detachable, i.e., removable without ripping the skin. In practice, kosher fish must have either ctenoid or cycloid scales.

Shark, catfish, octopus, squid, jellyfish, and eel are not kosher. All forms of shellfish - (clams, oysters, crab, lobster, and shrimp) - are not kosher. Sea mammals, such as dolphins, whales, and seals are not kosher.

Seaweed and other sea plant life are kosher, but require checking for infestation.

The kashrut status of swordfish and sturgeon is controversial, as they have scales while young but lose them later. Orthodox authorities say these fish are not kosher, although some Conservative rabbis allow their consumption.

Fish is considered parve (neutral) and may be eaten at both meat and dairy meals. In some Orthodox homes, fish served at a meat meal will be eaten on a separate plate, using a separate fork.

Birds
Kosher birds include: duck, goose, chicken, turkey, guineafowl and many others. As a general principle, scavenging birds such as vultures and birds of prey such as hawks and eagles (which will eat carrion when they find it) are not considered kosher, while other birds generally are. Leviticus outlines the non-kosher birds and the rest are all kosher; in practice, however, the identities of the birds listed as non-kosher are not all known, so religious authorities have restricted consumption to specific birds which Jews have traditionally eaten. Thus birds such as songbirds, which are consumed as delicacies in many societies, are not generally eaten although they might theoretically be kosher.

Kosher slaughter and preparation
Jewish law states that kosher mammals and birds must be slaughtered according to a strict set of guidelines, the slaughter (shechita) (שחיטה) being designed to minimize the pain inflicted, though the latter point is the subject of controversy. This necessarily eliminates the practice of hunting wild game for food, unless it can be captured alive and ritually slaughtered.

A professional slaughterer, or shochet (שוחט), using a large razor-sharp knife with absolutely no irregularities, nicks or dents, makes a single cut across the throat to a precise depth, severing both carotid arteries, both jugular veins, both vagus nerves, the trachea and the esophagus, no higher than the epiglottis and no lower than where cilia begin inside the trachea, causing the animal to bleed to death. Any variation from this exact procedure could cause unnecessary suffering; therefore, if the knife catches even for a split second or is found afterward to have developed any irregularities, or the depth of cut is too deep or shallow, the carcass is not kosher (nevela) and is sold as regular meat to the general public. The shochet must not only be rigorously trained in this procedure, but also a pious Jew of good character who observes the Sabbath, and who remains cognizant that these are God's creatures who are sacrificing their lives for the good of himself and his community and should not be allowed to suffer. In smaller communities, the shochet is often the town rabbi or the rabbi of one of the local synagogues; large factories which produce Kosher meat have professional full time shochets on staff.

Once killed, the animal is opened to determine whether there are any of seventy different irregularities or growths on its internal organs, which would render the animal non-kosher. The term glatt kosher (although it is often used colloquially to mean "strictly kosher") literally means "smooth", and properly refers to meat where the lungs have absolutely no adhesions (i.e. scars from previous inflammation).

As Jewish law prohibits the consumption of the blood of any animal, all blood and large blood vessels must be removed from the meat. This is most commonly done by soaking and salting, but also can be done by broiling. The hindquarters of a mammal are not kosher unless the sciatic nerve and the fat surrounding it are removed (Genesis 32, last verse). This is a very time-consuming process demanding a great deal of special training, and is rarely done outside Israel where there is a greater demand for kosher meat. When it is not done the hindquarters of the animal are sold for non-kosher meat.

Gelatin
A controversial topic is the status of gelatin. True gelatin consists of denatured proteins, and comes from the processed hides or bones of animals. Most gelatin is made from pigs or from cows which were not slaughtered as described above, including the icing on Kellogg's Pop-Tarts. This also affects the status of marshmallows, which contain gelatin as one of their principal ingredients. However, Kraft's product "Jell-O," as of recently, contains only Kosher gelatin. See Kraft's FAQ's.)

Another issue with gelatin is whether it is parve ('not dairy, nor meat'). A kosher parve 'gelatin' made from vegetable gums such as carrageenan combined with food starch from tapioca (which is also suitable for vegans) is commercially available in supermarkets which have substantial Kosher food sections. It does behave differently than protein-based gelatin, however, and cannot always be substituted directly for animal gelatin without modification of the recipe. Other gelatin-like materials available include combinations of carrageenan and other vegetable gums, such as guar gum, locust-bean gum, xanthan gum, gum acacia, and agar, chemically modified food starch, and chemically modified pectins. Recently, such products have come to be used in prepackaged gelled fruit products, where animal-based gelatin was previously used.

Although most gelatin is usually considered non-kosher, as explained above, several prominent rabbinic authorities have noted that gelatin undergoes such extensive processing and chemical changes that it no longer has the status of meat, and as such may be considered parve and kosher. This is the position adopted by a substantial minority of Orthodox rabbis, including Rabbi Ovadia Yosef, the former Sephardic Chief Rabbi of Israel and arguably the most revered living posek for Orthodox Sephardi and Mizrachi Jews. Conservative Judaism, likewise, holds that gelatin is kosher because it undergoes "such a complete change." An explanation of the legal principles surrounding this ruling can be found in the United Synagogue of Conservative Judaism's publication Keeping Kosher: A Diet For the Soul (2000). Similarly, most Reform Jews accept that all gelatin is kosher. Virtually all American Orthodox authorities, however, reject this position.

Insects and other invertebrates, reptiles, and amphibians
With four exceptions, all insects and other invertebrates (including those usually consumed as seafood), all reptiles, and all amphibians are considered 'loathsome', 'crawling' creatures, and are forbidden by the Torah. The exceptions are a type of locust, the kosher locust native to the Arabian peninsula, encompassing four distinct species. The tradition for identifying which species of locust were and were not kosher has been lost among all Jews except the Jews of Yemen. (One hypothesis links these kosher insects to the Biblical manna which was provided as food for the Israelites in the desert).

Bee honey is Kosher, even though bees are not, because the honey is made by the bee, not a secretion of the bee.

In the summer of 2004, a controversy arose in New York City over the presence of copepods (tiny crustaceans) in the city water supply. While some authorities hold that these creatures are microscopic and therefore negligible, others note that they are almost the size of a small insect, such as a gnat, and far larger than a bacterium or other single-celled creature; and in fact can be detected by the naked eye. As of this writing a definitive ruling has not been produced as to whether copepods are kosher, but many families have begun using filters on their drinking and cooking water supply.

Dairy
Milk and milk-derived products derived from kosher animals are always kosher. All milk from cows, goats, and sheep is kosher. In the past, when milk from cows was more expensive, adulteration with camel milk or horse milk was a serious issue; today this is not considered a practical concern in the USA or in most western countries. As such, some Haredi rabbis, most Modern Orthodox rabbis, and all Conservative rabbis hold that Food and Drug Administration (FDA) or European Medicines Agency (EMEA) supervision is sufficient for milk to be considered automatically kosher. However, many Orthodox Jews still adhere to the centuries-old ruling that only "Cholov Yisroel" (חלב ישראל) milk and dairy products may be consumed; this label means that the milk has been under constant supervision from milking to bottling, to make sure that it is not mixed with the milk of a non-kosher animal. Some of those who only drink Cholov Yisroel will, however, consume powdered milk.

Cheese
Cheese is a dairy product. Hard cheeses, however, are made from milk and rennet, an animal product.

Rennet is the enzyme used to turn milk into curds and whey; most forms of rennet derive from the lining of the stomach of an animal. Kosher rennet may be made from the stomachs of kosher animals slaughtered in conformance with the laws of kashrut, or may be made from vegetable or microbial sources. The Mishna and Talmud (in Avodah Zarah and Hullin) state that cheese made with rennet derived from a non-kosher animal is non-kosher. Orthodox authorities follow this ruling, and hold that rennet is a "d'var ha'ma'amid" (דבר המעמיד), an ingredient which changes the food so significantly that its presence cannot be considered negligible, so that even tiny amounts make the food it is added to non-kosher. Conservative authorities classify rennet as something that has changed so much from its original form that it is a "d'var chadash" (דבר חדש), "something new", and thus is no longer non-kosher. In practice Orthodox and some Conservative Jews eat only cheese made with kosher rennet, while other Conservative Jews follow the Conservative ruling and eat any hard cheese.

Waiting between meals
Historically, the extent of the restriction on meat/dairy mixtures has evolved over time and locale.

The original prohibition of meat/dairy mixtures is found in three verses in the Torah, which identically state, “You shall not cook a kid in its mother’s milk,” (Ex 23:19, 34:26, Deut 14:21). These verses are the ultimate basis for not eating meat and milk together. However, this requirement is much less restrictive than Rabbinic Judaism's prohibition against all mixtures of milk and meat. Rabbinic tradition relies on the existence of an Oral Torah, which in this case maintains that all mixtures of milk and meat are intended by the verses.
 * I. Biblical text

The Talmudic Rabbis (Chullin 115b) state that the verses only prohibit meat actually being cooked in milk, but the rabbis also added in a prohibition of eating meat with milk products. Additionally, they mandated a waiting period after the consumption of meat before dairy is allowed to be eaten. Mar Ukva tells how his father would not eat dairy after a meat meal, but rather would wait until the next day. Mar Ukva himself would not eat dairy at the same meal, but would at the next one. (Chullin 105a) The exact time period "between meals" is thus of importance in determining the amount of time one must wait.
 * II. Talmudic period

Tosafot (Chullin 105a) explains that as long as one has cleared the table after the meal and recited the blessing after a meal, then one may begin a new meal with dairy. Maimonides explains that waiting is necessary because meat becomes stuck in the teeth longer than other foods. Another reason is that it takes approximately six hours to digest meat. Because Maimonides writes "about six hours" and not simply "six," some interpret this to mean that 5½ hours of waiting is allowed. He also connects it to health issues and idolatry. The Shulchan Aruch, on the other hand, requirs waiting a full six hours for meat, including fowl, even if one has just been pre-chewing food for a baby and not really eating. If food is stuck between teeth one must take it out. This ruling is binding for Sephardi Jews. Ashkenazi Jews, however, have various customs. Most European Jews will wait six hours, even if the table is cleared and the blessings have been recited. German Jews wait three hours, and Dutch Jews wait only one.
 * III. Medieval and Modern periods

Eating meat after dairy is considered less problematic. One must only (a) say the blessings, (b) clean and rinse mouth, and (c) wash hands.

Basic information
Milk products and meat products may not be eaten together in the same meal or cooked together. Jewish law thus mandates a set of 'fence' laws that prevent this from happening:
 * cooking meat and milk together is prohibited, even if the resulting dish is not eaten;
 * eating milk and meat together is prohibited even if they are not cooked together; and
 * no benefit can be attained from such activity.

Note that in most current forms of Judaism (but not among all Karaites, Ethiopian Jews and some Persian Jewish communities), this even applies to the flesh of birds, not just mammals. Most observant Jewish homes maintain two sets of silverware, cookware, cups, and dishes. One is for milk (Yiddish milchig, Hebrew halavi) dishes, and one is for meat (Yiddish fleishig or fleishedik, Hebrew basari) dishes. This prevents any trace of meat or dairy from being accidentally mixed. (Foods that contain neither milk nor meat are considered "neutral" -- Yiddish parev, modern Hebrew parve). All foods which do not fall into the categories of meat or dairy are considered parve, and can be consumed freely with either meat or dairy. This includes all fruits and vegetables and foods derived exclusively from such sources; salt and other non-organic foodstuffs. Fish is considered parve, and may be eaten directly before or after both meat and milk, but see Seafood above.

Jewish law considers glass (and some say Pyrex) to be non-absorbent; thus, one could use just a single set of glass plates and dishes. In practice, this is rarely done amongst Ashkenazi Jews because it is held that it would weaken the traditional system of kashrut observance. However, it is common within most religiously observant households to allow drinking glasses to be used for both dairy and meat meals, as long as they are thoroughly washed. Amongst Sephardim, glass dishes are often used for both milk and meat &mdash; including for hot food.

There are varying views on how long to wait before consuming milk or dairy after the other. Traditionally, three distinct customs are observed regarding how long it is necessary to wait after eating meat before eating dairy foods again; most Eastern European communities wait six hours, German Jews wait three to five hours, and Dutch Jews wait 55 minutes.

Produce
Various laws apply to fruits, vegetables and produce. Most of these apply only to produce of the Land of Israel:
 * Orlah - fruits, harvested from a tree, less than three years after its planting (Mishnah tractate Orlah 3:9, Shulchan Arukh Yoreh De'ah 294:9-10)
 * Various tithes (Shulchan Aruch ibid ch. 391-393):
 * Terumah - originally given to the Kohanim (priestly caste)
 * Maaser Rishon - originally given to the Levites
 * Maaser Sheni - originally consumed in Jerusalem or given to the poor (in specific years)
 * Shmita - produce from each seventh year (Mishna tractate Shevi'it and Maimonides Hilchot Shevi'it ve-Yovel)
 * Challah - a portion of dough which must be given to the Kohanim (Mishna tractate Challah, Shulchan Aruch ibid 322-330)

Grains and cereals
Unprocessed grains and cereals are kosher. Processed items (e.g. dry cereals, baked goods) may contain small quantities of non-kosher ingredients; therefore Orthodox Judaism holds that these goods should generally not be consumed unless there is a hechsher (mark of rabbinical certification of kashrut) on the product. Conservative Judaism often is more lenient, and holds that a careful reading of the ingredients is sufficient.

Kosher for Passover
During Passover, there are additional restrictions on what foods may be eaten. Jewish law prohibits the consumption of leavened products, and furthermore any product made from the so-called "five species" of grain – conventionally viewed to be wheat, rye, barley, spelt, or oats – which may have been inadvertently briefly moistened sometime after harvest, and thus begun the fermentation process which is key to leavening. The exception to this rule is matza, which has been ritually supervised from harvest to packaging to ensure that no leavening has occurred.

Ashkenazi Jews are further restricted, by custom, from eating rice, legumes, and corn (collectively called kitniyot) during Passover. The reasoning for this restriction is historic: Grains and kitniyot were once stored together and it was difficult to ascertain whether there had been any mingling. Due to the prevalence of corn syrup in American processed foods, many common items are disallowed for Ashkenazic Jews during Passover. Coca-Cola produces and distributes "kosher Coke" (a version of Coke made without corn syrup) during Passover in the United States. In order to prevent inadvertent consumption of leaven, observant Jews maintain an entirely separate set of dishes, cutlery, pots, pans, etc. for Passover, much as they maintain separate sets of kitchenware year-round for milk and for meat. Before Passover, the house is rigorously cleaned to eliminate any remnants of chametz, no matter how small. Some Jews even maintain a separate kitchen for use during Passover.

Other produce
All fresh fruits and vegetables are kosher in principle. Jewish law requires that they be carefully checked and cleaned to make sure that there are no insects on them, as insects are not kosher (except certain grasshoppers and crickets according to the Jews of Yemen only, see above). In the last century emphasis on this aspect has increased, especially in the Haredi Jewish community. Many Haredim avoid certain vegetables, such as broccoli, because they may be infested and exceedingly hard to clean. Responding to this issue, some companies now sell thoroughly washed and inspected produce for those who do not wish to do it themselves, even going to the trouble of filtering the wash water to ensure that it carries no microscopic creatures (see discussion of such animals in tap water, above).

There are actually some restrictions on consumption of produce. The fruit of a tree for the first three years cannot be consumed (the law of orlah). For crops grown in the Holy Land, tithes must be taken and allocated according to the precepts of the Bible, otherwise the entire crop is not considered Kosher.

Eggs
Eggs from kosher birds are kosher; they are also considered parve (neutral, neither milk nor meat). Traditionally, eggs are examined in a glass cup to ascertain that they contain no blood. Eggs containing blood in the white may be used according to Sephardi halakha if the blood can be removed, but the egg must be discarded if any blood is found on the yolk. Ashkenazim generally do not distinguish between blood in the white or on the yolk. Partially-formed eggs found inside slaughtered birds may be eaten, but they must undergo the same process of blood removal as the animal, and these eggs are considered to be fleishig (status of meat) in Ashkenazi Judaism.

Canned and frozen foods
Most canned and frozen foods are usually permissible since manufacturers add only water and spices during the packaging process. Sometimes, however, fruits or vegetables are prepared with milk products or with non-kosher ingredients such as non-kosher meat broth. Orthodox Judaism thus holds that canned and frozen goods should generally not be consumed unless there is a hechsher (mark of rabbinical certification of kashrut) on the product. Conservative Judaism often is more lenient, and holds that a careful reading of the ingredients is sufficient.

Wine and grape products
Most Orthodox Jews will not drink wine produced by non-Jews. The prohibition on drinking such wine, called "yayin nesekh," goes back to pagan times, when wine was used for idolatrous purposes. One area of leniency is in regard to pasteurized wine, which falls under the category of "cooked wine" ("yayin mevushal"). Such wine was historically viewed as less suitable for religious practices, and is therefore not subject to the same prohibitions as uncooked non-Jewish wine, primarily regarding the way it may be handled. However, even mevushal wine is forbidden without proper supervision.

Conservative Judaism views on wine
Within Conservative Judaism, the law is regarded as being upheld, but the practice has significantly changed. In the 1960s the Committee on Jewish Law and Standards approved a responsum ("legal ruling") by Rabbi Israel Silverman on this subject.

He notes that most classical Jewish authorities agree that Christians are not considered idolaters, and that their products cannot be considered forbidden in this regard. He also noted that most wine-making in the United States is fully automated. Based on 15th-19th century precedents in the responsa literature, he concluded that wines manufactured by this automated process may not be classified as wine "manufactured by gentiles", and thus are not prohibited by Jewish law. This responsum makes no attempt to change halakhah in any way, but rather argues that most American wine, made in an automated fashion, already is kosher by traditional halakhic standards. Some criticism was later made against this teshuvah, because (a) some wines are not made by automated processes but rather, at least in some steps, by hand, and (b) on rare occasions non-kosher fining ingredients are used in wine preparation.

A later responsum on this subject was written by Rabbi Elliot N. Dorff, and also accepted by the CJLS. Dorff noted that not all wines are made by automated processes, and thus the reasoning behind Silverman's responsum was not conclusively reliable in all cases. He explored rabbinic thought on Jewish views of non-Christians, also finding that most poskim refused to consign Christians to the status of idolator. Noting that many foods once considered forbidden if produced by gentiles (wheat and oil products) were eventually declared kosher, he concluded that wine and grape products produced by non-Jews are permissible.

Dietary restrictions often associated with kashrut
Mixing fish and meat, while technically kosher, is nevertheless restricted by rabbinical law. The Talmud prohibited this specifically, on the grounds of the Torah requirement to carefully guard one’s health. Though it might be presumed that those in Talmudic times did not have the wealth of medical knowledge that we have today, many observant Jews continue to follow this restriction, believing that the scholars of the Talmud may have known something we do not, or that there might be other unstated reasons for the restriction.