Ouf Tamey - non-kosher fowl:
The Torah similarly differentiates between kosher and non-kosher fowl. Unlike animals, the Torah gives no signs to differentiate between kosher and non-kosher fowl. The Torah merely lists twenty-four types of forbidden fowl; all other fowl are assumed to be kosher. The Talmud does provide signs to identify non-kosher fowl. However, since we lack the experience to apply these rules, we are permitted to eat only those fowl traditionally accepted as kosher. All variations of the common chicken are accepted as kosher. Similarly, common domestic ducks, geeses and doves are considered kosher. Some communities have a tradition that the quail is a kosher fowl. With the appearance of turkeys, Rabbis questioned whether a reliable tradition exists about their kashrut. Common custom today accepts turkeys as kosher fowl. There is no definitive tradition about the status of a pheasant, peacock, guinea hen, partridge, swan, or certain species of wild ducks, geese, pigeons and doves; therefore, they should not be eaten. The eggs of any non-Kosher fowl are also forbidden to be eaten.
Neveilah - carrion:
Even a kosher animal or fowl (the laws of neveilah do not apply to fish) may not be eaten unless it is slaughtered in the prescribed manner. An animal slaughtered improperly or an animal that died in any other manner is a neveilah and may not be eaten. The laws of shechita (ritual slaughtering) are complex and are discussed in Jewish Law at length.
Treifah - mortally injured:
Any animal or fowl which, as a result of a birth defect, disease or inflicted wound, suffers from a mortally defective organ or limb (or an animal close to death) may be considered a Treifah. These defects are enumerated in the Talmud. A defect not listed in the Talmud does not render the animal a Treifah even if according to current medical knowledge the animal is certain to die shortly. Conversely, a defect that is listed by the Talmud renders the animal Treifah regardless of current medical opinion. For example: an animal lacking certain organs, an animal with certain organ walls perforated or certain bones fractured is considered a Treifah. Thus, even if one slaughters a kosher animal properly, it may nevertheless be un-Kosher to eat if it is afflicted by any of these injuries. Although every animal and fowl is assumed to be free of any of these injuries and need not be examined, the lung of an animals must be examined after slaughtering to ascertain that the animal suffers no abnormality that renders it a Treifah. This examination is called "bedikah". The rules of Treifah are of great relevance in the slaughtering house but rarely affect the Jewish home since most meats are delivered prepared and packaged. However, if one notices a broken wing or leg or a discolored drumstick, one should consult a Rabbi.
Sheretz - swarming insects and rodents:
The Torah prohibits us from eating any rodents, worms, amphibians or creeping, swimming or flying insects. One who eats fruits or vegetables in which worms, ants or mites are commonly found must examine the fruit carefully before eating.
Dag Tamey - non-kosher fish:
The Torah permits only those fish that have fins and scales; any other fish is prohibited. Some fish have very small scales and still others lose their scales upon being removed from the water; they are, nevertheless, permitted. Swimming creatures that are not fish (like sea horse or squid) are included in the prohibition.
Dam - blood:
The Torah forbids eating the blood of even a kosher animal or fowl. Thus, after slaughtering, all meat to be cooked must be salted beforehand. Certain organs require special treatment to rid them of their blood. The liver is so permeated with blood that only broiling can remove that blood. Fish blood is permitted unless it is recognizable as fish blood (that is, it contains fish scales).
Cheilev - non-kosher fats:
The fats on certain internal organs must be removed from a kosher slaughtered cattle, sheep or goat before the meat may be eaten. This prohibition applies to commonly domesticated animals only (like cattle, sheep and goats), not to fowl or wild forest animals. Removal of the forbidden fats is a difficult task and must be done by a skilled expert. This process is called nikur and is usually done in the slaughtering house. At times, butchers themselves must do nikur. Thus, it is not sufficient to merely obtain meat with a proper slaughtering supervision; one must also determine that the butcher is a skilled, knowledgeable and G-d-fearing individual who does nikur under proper Rabbinical supervision.
Gid Hanasheh - the sciatic nerve:
The Torah prohibits eating the gid hanasheh - the sciatic nerve in both hind thighs of any kosher land animal (domesticated or wild). The difficult process of the removal of the nerve and the fat surrounding it is also called "nikur" and must be done with great care by a G-d-fearing skilled expert. In most countries, the hind part of an animal is not eaten at all thereby avoiding entirely the difficult process of removing the prohibited fats and nerves.
Eiver Min HaChai - a limb from a living creature:
One may not eat a limb of an animal or fowl that was removed while the animal was alive. Although this prohibition does not apply to fish, one should nevertheless not eat part of a fish while the fish is alive. Incidentally, the law of eiver min hachai is the only law of kashrut that applies to non-Jews as well. Thus, a Jew may not provide a non-Jew with eiver min hachai meat since, by doing so, he assists him in transgressing a Torah law.
Tevel - produce from which the tithes were not removed:
One may not eat fruits and vegetables grown in The Land of Israel unless the required tithes - called terumot and maasers, were set aside. It is common today that fresh fruits and vegetables (or even orange juice concentrate) are imported from the Holy Land. These fruits may not be eaten without setting aside these tithes beforehand. One should consult a Rabbi who knows as to the proper procedure for tithing.
Orlah - fruits of the first three years:
One who plants a fruit tree, whether in The Land of Israel or not, may not eat any produce of the first three years growth. One who replants a tree may also be required to wait three years before eating any of the fruits. One should also consult a Rabbi to determine when the three years have elapsed. In addition, one should inquire about the particular laws of a grape vine.
Chadash - new (fresh) grain:
The Torah prohibits eating any of the five types of grain (wheat, barley oats, spelt and rye) that took root after the sixteenth of the Hebrew month of Nissan until the following sixteenth of Nissan. There is a difference of opinion whether this Biblical prohibition applies to grains grown outside of The Land of Israel.
Yayin Nesech - wine of libation:
One may not drink or derive any benefit from wine that has been poured in a sacrificial manner to an avodah zarah - idolatry. In addition, this prohibition applies to anything served to an idol in a sacrificial mannered. Other non-Jewish wines are forbidden through Rabbinic injunction and will be discussed below.
Kilayim - different species grown together:
One may not plant vegetables or grains near one another this is called kilaei zeraim. One also may not plant any vegetable or grain near a grape vine: this is called kilaei hakerem. Two distinctions between the two are the former is forbidden only in The Land of Israel and does not cause the produce to become prohibited. The latter applies in any country and causes the produce to become prohibited to be eaten or derive benefit (hana'ah) thereof.
a) The Torah prohibition of mixing meat and milk includes only meat and milk of a kosher domestic animal (such as cow, sheep and goat). Rabbis extended the prohibition to include meat and milk from a chayah - a non-domestic animal (such as deer) and fowl.
b) Rabbis broadened the prohibition of eating the siatic nerve to include parts of the nerve and the fats surrounding it which are not included in the Biblical prohibition.
Chalav Akum - non-Jewish milk:
Milk that was not milked in the presence of a Jew is forbidden by Rabbinic injunction. Rabbis feared that the non-Jew may have mixed non-kosher milk (like milk from a non-kosher animal) into the milk.
Gevinat Akum - non-Jewish cheese:
Rabbis prohibited cheese made by non-Jews since their cheese is, with all probability, produced with non-kosher rennet.
Yayin Akum - wine touched by a non-Jew:
Rabbis prohibited (even to derive benefit from) the wine of a Jew if it was touched and moved (or even if it may have been touched) by a non-Jew. Rabbis were concerned that the non-Jew may have poured some of the wine as an offering to his avodah zarah. These laws are complex and of importance to anyone who has non-Jewish cleaning help.
Bishul Akum - non-Jewish cooking:
One may not eat food cooked by a non-Jew. Rabbis feared that this may precipitate an inappropriately close personal relationship between Jew and non-Jew.
Pas Akum - non-Jewish bread:
Similarly, Rabbis prohibited eating bread baked by a non-Jew.
Stam Yoinom - non-Jewish wine:
One may not drink wine of a non-Jew, even if the wine was not poured to avodah zarah. This prohibition is also based on the concern that drinking his wine may cause a personal relationship between Jew and non-Jew.
Sakanah - dangerous foods:
Certain foods were prohibited by Rabbis out of concern for safety. Indeed, Rabbis were more stringent regarding a sakanah (danger), than a prohibition. Among these prohibitions is the prohibition of eating fish with meat.