Basic rule
Judaism: Only foods (or categories of foods) that are explicitly permitted can be eaten. Such foods are called kosher; foods that are not kosher are called traif.
Islam: Any food that is not explicitly forbidden (haram) is permitted (halal).
Meat
J: Only cloven-hoofed animals that chew their cud can be eaten. Thus, cows, sheep, and goats are OK among domesticated animals, plus the deer family. Pigs (cloven hoofs but don’t chew their cud) are forbidden. By-products made from prohibited animals are also prohibited.
I: Only pigs are explicitly prohibited in the Quran, and related by-products (such as lard, gelatin, etc.). Animals with claws and fangs (predators and carrion eaters) are prohibited implicitly but not explicitly. Some foods are considered disgusting even though not expressly prohibited (makruh). This can vary by region for animals such as donkeys, pelicans, weasels, foxes, ravens, and crocodiles, for instance.
Slaughter
J: Animal must be slaughtered appropriately, which includes the throat being slit in a quick and merciful manner. Any other form of death renders the animal non-kosher. After slaughter, the carcass is examined for defects and disease, the presence of which makes the meat non-kosher. Drinking of blood is prohibited, and this means that all the blood must be drained from the body, and the meat washed and soaked in salt to remove the blood. Certain parts of the animal may not be eaten, including certain fats and the sciatic nerve, both of which are found in the hindquarters; consequently, many Jews do not eat the hindquarters. NOTE: Observant Jews living away from a kosher butcher have to import their meat. Meat slaughtered by a non-kosher butcher is never acceptable (except in cases of starvation or medical necessity).
I: The animal must be slaughtered appropriately, which includes the throat being slit in a quick and merciful manner. Drinking of blood is prohibited, and this means that all the blood must be drained from the body. Game animals are OK, but the meat of any animal killed by a blow, falling from a height, or gored with horns is prohibited. NOTE: Muslims living in an area that does not have an official Muslim slaughterer can eat kosher meat that has met the rules of Jewish slaughter. If there is no kosher meat available, Muslims may eat meat from Christian butchers, excluding pigs.
Birds
J: The rules are complex because the Torah lists specific prohibited species, and the rabbis draw conclusions about broader prohibited characteristics. Basically, the common domesticated birds are OK, such as chicken, turkeys, ducks, geese, and pigeons. Birds of prey are prohibited. Only eggs from kosher birds are permitted.
I: Although not specifically forbidden by the Quran, birds of prey and carrion-eaters are considered to be prohibited.
Fish and seafood
J: Fish must have scales and fins. For example, catfish (fins but no scales) are not permitted. Lobsters, crabs and shrimp are prohibited, having neither fins nor scales. There is no particular slaughter method necessary for fish.
I: All seafood is permitted, and there is no particular slaughter method required. Some Muslims, noting certain sayings of the Prophet that crawling sea creatures (shrimp, crabs, lobsters, etc.) are disgusting, refrain from eating these. Similarly, catfish, while not explicitly prohibited, is not preferred.
Rodents and reptiles
J: Prohibited, since they don’t have cloven hoofs or chew their cuds. Also prohibited as creatures that “creep” and “crawl.” Prohibited by implication, but not directly. Insects Generally prohibited as creatures that “creep and crawl.” A few species of locusts are permitted, but we can no longer identify them with certainty (the ancient Hebrew terms are no longer clear).
I: Prohibited (except for certain locusts).
Alcohol
J: No prohibition, although some authorities require certification of the alcohol to ensure that there was no contact with non-kosher elements.
I: Anything that interferes with the clear functioning of the mind is prohibited. This includes alcohol and intoxicating drugs. Alcohol is prohibited either as a beverage or in food preparation; thus pure vanilla and other extracts pose a problem, as do mouthwashes with alcohol.
Vegetables and fruits
J: There are no prohibitions; any fruit or vegetable is permitted. However, some authorities exclude certain vegetables — like broccoli — to prevent the possibility that small insects or insect parts might have lodged in the tiny crevices.
I: There are no prohibitions; any fruit or vegetable is permitted.
Other
J: Any food that has been consecrated to an idol is prohibited. Eating meat and dairy products in the same meal is not permitted. The rules here become very complex, including separate dishes and silverware to be used for “meat” meals and for “dairy” meals. Traditional Jews check the ingredients on foods (thanks to modern labeling!) to ensure there is no mixture of dairy and meat products. The rules on cheeses are very complex, since cheese is curdled in rennet (a meat by-product, but not itself a food).
I: Any food that has been consecrated to another deity is prohibited. (Kosher food is OK, since it is killed in the name of Allah’s earlier Revelation.) Islam has no rules on mixtures of types of foods.
Food (or its absence) is usually an important part of any celebration. Although Christianity does not have specific dietary prohibitions, the rite of communion involves bread and wine, and Catholics tend to refrain from eating meat during Lent. Traditions such as Christmas puddings or Easter eggs also tie foods into religious celebration. And families, in all religions, tend to have traditional meals on holidays.
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