What does kosher mean? כָּשֵׁר

• Land animals: only those that have split hooves and chew the cud (Leviticus 11:3) – cattle, sheep, goats and deer are permitted; pigs, rabbits and camels are not.
• Fish: only fish that have both fins and scales (Leviticus 11:9). Shellfish are not kosher.
• Birds: the Torah lists forbidden birds (Leviticus 11:13–19); in practice only birds with an established tradition, such as chicken, turkey, duck and goose, are eaten.
• Slaughter: meat and poultry must come from an animal slaughtered by shechita and checked for certain defects; the blood is removed by salting.
• Meat and dairy are never cooked or eaten together (see the separate guide).
• Insects are forbidden, so fruit, vegetables and grains are checked for them.

The Torah presents these laws as part of holiness (Leviticus 11:44–45) and generally does not give a reason for them. Jewish tradition counts them among the commandments kept because God commanded them, even when the reason is not stated. Health explanations have been suggested by some commentators, but they are not the basis of the law.

A kosher kitchen keeps separate utensils for meat and for dairy, and buys meat, wine, cheese and processed foods with reliable supervision. A kosher symbol (hechsher) on a package means that a rabbinic organisation supervised its ingredients and production; standards differ, so people ask their rabbi which supervision to rely on.

Foods that are neither meat nor dairy – vegetables, fruit, grains, eggs and kosher fish – are called pareve and may be eaten with either.

Sephardim generally follow the Shulchan Aruch of Rabbi Yosef Karo and eat only meat that is “chalak Beit Yosef” – lungs with no adhesions at all – while the Ashkenazi “glatt” standard tolerates certain minor adhesions. Waiting times between meat and dairy also differ (six hours for Sephardim; six, three or one hour among Ashkenazi communities). Some Sephardi communities eat certain locusts by tradition; Ashkenazim do not.