Food is an integral part of culture. Available resources, culinary technologies, and local needs often dictate what and how people in each civilization eat. Religion and culture are also closely tied together in many societies, so belief systems also impact dietary customs. Kashrut, the Jewish dietary laws on kosher eating, is a perfect example of how these factors can shape the everyday diet.

The Origins of Kashrut

The Online Etymology Dictionary discusses the word “kosher” and related terms. Kashrut is a Hebrew word that can be translated as “fit,” “proper,” or “legitimate,” while kosher is a Yiddish word with origins traced to around 1850. The basic idea behind these terms is that certain foods are acceptable for consumption, while others are not.

Kosher dietary traditions come from both the Torah and the Talmud. Several passages in the first five books of the Tanakh give detailed commandments regarding what ancient Israelites could and could not eat. Chabad specifically mentions Leviticus 11 and Deuteronomy 14, where the bulk of the laws originate.

After Jewish communities spread throughout the world, more guidance on kosher practices was needed. My Jewish Learning explains that the Mishnah and the Gemara, the two texts of the Talmud, provided more clarification on kosher rules. Written by rabbis between the second and fifth centuries C.E., these texts include instructions on slaughtering animals, preparing foods, and separating utensils and cookware to avoid violating kashrut.

Foods Permitted by Kosher Traditions

While kosher rules are rather detailed, they’re based on several core commandments. The Orthodox Union, a kosher certification agency based in New York City, lays out the fundamentals of what may be eaten:

• Cud-chewing animals with split hooves
• Fish with fins and scales
• Certain fowl, including chicken, turkey, duck, and goose
• Eggs from kosher fish and birds
• Milk from kosher animals

Permitted foods fall into one of three categories: meat, dairy, and pareve. The third term, which means “neutral” in Yiddish, refers to foods that don’t contain meat or dairy: vegetables, grains, fruit, nuts, salt, water, and honey. Fish and eggs are typically considered pareve, but some observant communities do not eat fish with meat or dairy. Vegetarian and vegan Jewish people also avoid fish and eggs.

Foods Forbidden by Kashrut

Meanwhile, several categories of food are prohibited if one keeps kosher traditions. Animals that either chew cud or have split hooves but lack both characteristics aren’t permitted for consumption. Common examples include pork, camel, and rabbit. Reptiles, birds of prey, and certain insects are off-limits. Marine life without fins and scales, such as shellfish, eels, mollusks, cephalopods, dolphins, and whales, are also forbidden. Some fish species such as sharks and sturgeons are also non-kosher because their scales can’t be separated from the skin. Mixing meat and dairy is also forbidden in both cooking methods and consumption. Finally, blood may not be consumed in any form.

Practical Logic Behind the Rules?

Kosher dietary laws are intricate, but does any practical rationale exist behind them? Modern refrigeration didn’t exist when the Torah was written, plus there are serious risks of consuming raw or improperly cooked pork. Author Miri Rotkovitz discusses several advantages to kosher eating: the ability to host kosher-observant guests, ensured food quality, more humane slaughtering practices, and the ease of avoiding allergy-provoking foods such as dairy.

For individuals like Rabbi Bradley Artson, kashrut is bigger than practical concerns. He mentions the connection between kashrut and Jewish identity, plus the fact that other faiths like Hinduism and Islam also have dietary rules. Ultimately, Artson sees kashrut as visibly living Judaism’s values and inviting a sense of holiness into everyday activities.

And maybe that’s the point: Not everything we do needs a logical or scientific reason. If they bring benefits without harming others, our spiritual practices can provide nourishment and meaning when we need them most.