The word “kosher” describes food that is considered “appropriate” or “fit” for a Jew to eat. The practice of keeping kosher dates to the Torah. In Genesis 1:29, God commanded vegetarianism as the ideal diet was. Over time, the rabbis of late antiquity expanded the definition of kosher to include a variety of animals.
Chapter 11 of Leviticus defines kosher animals as those that chew their cud and have split hooves. Acceptable sea creatures must have both fins and scales. While the Torah describes acceptable birds, later authorities have added similar birds to the list. Birds of prey and scavengers are considered not fit for consumption. The Torah specifically forbids cooking a baby goat in its own mother’s milk.
Over the years, the rabbis in the Talmud continued to develop the principles of kashrut, the Hebrew word for kosher. The rabbis prescribed specific rules for slaughtering kosher land animals and birds which are more humane than standard commercial practice. Hashgacha is the rabbinic supervision of the production of food including slaughter which allows food to be considered kosher.
The prohibition about cooking a baby goat in its mother’s milk gradually expanded to the requirement to keep all milk and meat products separate. In order to ensure the separation of meat and milk, two sets of dishes and utensils are required. In addition, keeping kosher requires waiting several hours after eating a meat dish before consuming a dairy product, lest the two foods mix in the stomach.
There are three categories of kosher foods:
- Dairy which includes foods like milk, yogurt, cheese, ice cream, etc.
- Meat which includes all kosher fowl and animals slaughtered in the prescribed manner
- Pareve which means neutral. These foods are neither meat nor dairy. Fish, tofu, eggs, seeds, nuts, vegetables and fruits are in this category.