Kosher is the common English term for the set of Jewish dietary laws, known in Hebrew as kashrut. These rules govern which foods are permitted, how those foods must be prepared, and what combinations are allowed at the table. Observance ranges from strict religious adherence to cultural or personal preference, and practices vary among communities and individuals.
Basic categories and principles
Foods are commonly divided into three broad categories: meat (basar), dairy (chalav), and pareve (neutral). Pareve items include fish with fins and scales, eggs, fruits, vegetables, and many processed products that contain neither meat nor dairy. Meat and dairy must not be eaten together: many observant Jews use separate sets of dishes, cookware and utensils for each, and allow a time interval between consuming one and the other. The precise waiting time varies by community and custom.
Which animals and seafood are permitted
Land mammals are permitted only if they both chew their cud and have split hooves; classic examples are cows and sheep. Animals that lack one of these signs—for example, pigs—are not kosher. Permitted birds are identified by tradition and rabbinic lists rather than a single physical test; commonly eaten kosher birds include chicken, turkey and duck in many communities, while birds of prey are forbidden. Seafood is permitted only if it has both fins and scales; shellfish and other invertebrates are not kosher.
Slaughter, blood, and preparation
Animals that are eaten must be slaughtered according to a ritual process called shechita, performed by a specially trained person (a shochet). The laws also prohibit consuming blood; therefore kosher meat is salted and rinsed or otherwise treated to remove blood. Certain fats and the sciatic nerve are traditionally forbidden, and their removal is part of the butchering process in communities that observe those rules.
Kitchen practice, certification, and modern life
Keeping a kosher kitchen involves not only permitted foods but also how they are stored, cooked and served. Many people maintain separate sinks, dishwashers, dishware and cooking implements for meat and dairy. Processed foods and ingredients are often identified by kosher certification marks issued by rabbinic authorities or agencies; these certifications indicate supervision of ingredients and production methods. Kosher food availability and certification have expanded greatly in modern times, and many restaurants, manufacturers and retailers cater to kosher consumers.
History, cultural role, and notable distinctions
The laws of kashrut appear in the Hebrew Bible and were elaborated by later rabbinic literature; over centuries they have become central to Jewish identity and practice for many communities. Beyond dietary restrictions, kosher laws serve ritual, ethical and communal functions: they mark time and identity, create occasions for communal standards, and influence daily routines. There are important distinctions between general kashrut and more specific observances, such as additional restrictions observed during Passover or stricter standards described as glatt in some traditions.
- Non-kosher foods are often called treif, meaning "torn" or unfit.
- Neutral (pareve) foods can be eaten with either meat or dairy.
- Modern labels and supervision help consumers identify kosher products.
For further reading on historical sources and contemporary practice, see introductory guides and community resources: Jewish texts and traditions, general information about food laws, and detailed explanations about meat and slaughter practices. These resources provide context for how kashrut is observed today and how it developed over time.
