The Laws of Kashrut

  1. The first category of kashrut laws deals with animals and their byproducts.

  1. A kosher animal must be a ruminant (chew its cud) and have split hooves - so cows, sheep, goats and deer are all kosher, whereas camels (ruminants without split hooves) are not kosher, and pigs (having split hooves but not chewing their cud) are not kosher. Most common fowl are kosher, like chickens, ducks and geese, but the birds of prey (hawks, eagles, owls, parrots) are not kosher. A sea creature is only kosher if it has fins and scales, so most species of fish are kosher (tuna, salmon, flounder, trout, etc.) but all shellfish are not kosher; dolphins and whales are not kosher, jellyfish, sea slugs (my sincere apologies about this one) and squids are not kosher either. There are four species of locust that are kosher, but are not commonly consumed by the majority of Jews (Thank G-d for that). Any product of a non-kosher animal is also non-kosher (e.g. milk, gelatine, rennet). The exception to this rule is bee's honey.

  1. In order to eat an animal or bird it must be slaughtered according to Jewish law (Shechita). This involves cutting the animal's trachea and oesophagus (the carotid artery and jugular veins are also severed in this operation, as are most arteries and veins leading to and from the brain) with a surgically sharp knife that has been thoroughly checked for nicks beforehand. The cut must be swift, without pause, tearing or vertical pressure and must be only done by an expert. It must be performed on the neck of the animal not higher than the epiglottis and not lower than where cilia begin inside the trachea. This method of slaughter reduces the blood pressure in the brain to zero immediately so that the animal loses consciousness in a few seconds and dies in less than a minute. (For comparative scientific studies of shechita and other methods of killing, refer to Shechita: Religious, Historical and Scientific Perspectives, by Munk, Feldheim Publishers, New York, 1976) Fish must be killed before being eaten, but no particular method is specified in Jewish law.

  1. The animal or bird must then be determined to be free of treifot, which are 70 different categories of injuries, diseases or abnormalities whose presence renders the animal non-kosher.

  1. Not all parts of the animal may be eaten. Certain fats, known as Chelev, may not be eaten. As much blood as possible must be removed from the meat, either by soaking, salting and rinsing or by broiling over a fire. In addition the sciatic nerve (gid hanasheh) in each leg and the fat surrounding the nerve must be removed.

  1. It is forbidden to cook (even without eating), eat (even without cooking) or derive any benefit (e.g. feeding pets) from mixtures of milk (and its by-products), and meat (and most of its by-products). It is also forbidden to cook or eat dairy products together with poultry. Fish, fruits, vegetables, grains, eggs are neutral (pareve).

  1. The second category of laws are those that deal with agricultural products.

  1. One may not eat of fruit of a tree in the first three years from the time of its planting. (Orlah) 

  1. In the Land of Israel, tithes must be taken from all crops. Some tithes are divided among the Priests (Kohanim), Levites, and the poor. Others must be eaten in Jerusalem by the owners and shared with the local population. If these tithes are not separated out of the crop then the produce may not be eaten -- the wheat, barley or fruit is actually not kosher until the commandments of tithing have been fulfilled.

  1. The third category are products that were prohibited because of what they may contain or for their sociological impact.

  1. Wine and grape-juice products may only be used if produced by Jews. Pagans used to use wine for their ceremonies and used to dedicate wine to their gods, which would make the wine Biblically prohibited. The Sages forbade all "non-Jewish wine" even if it was not known to have been used for pagan purposes. In addition, sharing wine creates a certain feeling of intimacy that the Sages wanted to discourage between Jews and Gentiles as a barrier against intermarriage.

  1. Milk products must be supervised in order to ensure that they only come from kosher animals. The rennet in cheese must also only come from a kosher animal that has been slaughtered correctly and checked for treifot. 

  1. Any cooked or processed foods must have some form of supervision to ensure that there are no non-kosher products used in their preparation.

The above overview is obviously not a comprehensive legal guide to the laws of kashrut, it is a bare bones categorisation of the laws, for the purpose of understanding their rationale. For a more detailed exposition of the dietary laws, see The Jewish Dietary Laws, Isidore Grunfeld, Soncino Press, London.

Reasons for the Commandments

Before going into the reasons for the laws in detail a second introduction is necessary. When we attempt to explain the philosophy of any law of the Torah we have to understand some general ideas about the concept of taamei hamitzvot, reasons for the commandments.

Join now!

The verse states, "Contemplate ("taamu", literally "taste") and see that G-d is good.." (Psalms 34:9) Judaism does not expect people to be capable of fulfilling the commandments without having any appreciation at all of their depth and beauty - their "taste." Study of the reasons for the commandments (taamei hamitzvot) is perhaps one of the most effective methods of gaining this appreciation of the Jewish way of life. The very idea of investigating the reasons for the commandments, however, raises a number of issues.

  1. Does the authority of a commandment rely upon our comprehension of its rationale? ...

This is a preview of the whole essay