This brief survey of how the meat of kosher animals is prepared, including its separation from milk products, is not an exhaustive guide. Those wishing to observe these regulations should seek guidance from a rabbi or someone else familiar with the laws and practice of kashrut.
The strict prohibition of blood in the Bible (Leviticus 7:26-27; 17:10-14) is the basis for the laws governing the preparation of the meat of animals and birds for food. The usual practice is first to soak the meat in cold water for half an hour and then to salt it thoroughly and leave it covered in salt on a draining-board so that as much as possible of the blood is drained off. An alternative method is to roast the meat over a naked flame. In many communities, nowadays, the butcher attends to this process, relieving his customers from having to do it themselves. The blood of fishes is permitted so there is no process of “salting” for fish.
The biblical text repeats three times the prohibition of “seething a kid in its mother’s milk” (Exodus 23:19; 34:26; Deuteronomy 14:21). This might originally have been intended to prohibit an act of such callousness or to ban any attempt at influencing nature by some kind of sympathetic magic, but in the rabbinic tradition, the prohibition means that no meat of any animal may be cooked in any milk (the “kid” and the milk of the “mother” referring only to the type of the forbidden mixture, i.e. the milk and meat of animals like a “kid” and its “mother”). As for the threefold repetition, this is said to forbid the initial cooking-together of meat and milk; to forbid the eating of meat and milk cooked together; and to forbid any benefit from the mixture (by selling it, for example, to a non-Jew to whom these laws do not apply).
According to one opinion in the Talmud, it is permitted to cook the meat of birds in milk but the accepted opinion is that this, too, is forbidden by rabbinic law on the grounds that if such is permitted, people may conclude that it is also permitted to cook in milk the meat of animals. This is an example of the rabbinic principle of “making a fence around the Torah.” A further rabbinic extension is to forbid the eating of meat and milk together even when they have not been cooked or boiled together; for example, to have a glass of milk together with meat, or to eat meat together with buttered bread.
Derived from this is the current practice of waiting, after a meat meal, before having a dairy meal. Some devout Jews wait for one hour between a meat and a dairy meal; in Anglo-Jewry, people often wait for three hours; and, in the usual custom among Orthodox Jews, the waiting period is as long as six hours. The basic reason for this waiting period is to make sure that no meat is lodged in the teeth, and so it is permitted to have a meat meal almost immediately after a dairy meal (generally after only half an hour). Because of these rules, it is the usual practice among Orthodox [and other observant] Jews to have two separate sets of cooking utensils, crockery, and cutlery for meat and dairy meals.
Because of the verse prohibiting [the eating of] the sciatic nerve (Genesis 32:33), this nerve must be removed from the animal by the process known as “porging.” In communities like that of Anglo-Jewry, where there is a lack of skilled porgers, the hindquarter meat is not eaten at all. In Israel and most other countries, porging is done and the meat of the hindquarters eaten, though the fat of the stomach and that on the kidneys is forbidden, since these were offered as a sacrifice in Temple times (see Leviticus 7:22-24).
Reprinted with permission from The Jewish Religion: A Companion, published by Oxford University Press.
Pronounced: KOH-sher, Origin: Hebrew, adhering to kashrut, the traditional Jewish dietary laws.