Beef and lamb are well-known examples of meat from kosher animals which may be eaten once the correct process of slaughtering and koshering has been followed. However, not every part of a kosher animal may be eaten. Some fats are kosher, some are not.

Cheilev refers to specific hard fats found in domesticated kosher animals such as cattle, sheep, and goats. These fats are located around certain organs, including the kidneys, liver, and intestines, and are distinct from the softer fats and marbling found within the meat.

The Torah explicitly forbids consuming cheilev, stating, “Any cheilev of an ox, sheep, or goat you shall not eat.”1

Permitted vs. Forbidden Fats

But not all animal fat is prohibited. Permitted fat, known as shuman, includes the fat within muscle tissue and is commonly found in kosher cuts of meat.2

Why is cheilev forbidden? In the Holy Temple, these fats were considered the choicest portions of an animal offering and were designated to be burnt on the Altar.3

By reserving them for G‑d, the Torah teaches that not every physical desire—even a permitted one—needs to be indulged.4 Nachmanides5 adds that holiness does not mean complete rejection of physical pleasures, but requires channeling them properly—in this case, the best part of the animal being given to G‑d.

The Rebbe explains6 that one had to wait until the cheilev was completely burned on the Altar before partaking in the meat of the rest of the sacrifice—to symbolize that the proper way to fulfill a mitzvah is with the enjoyment of serving G‑d and fulfilling His will.

For more on this, see: Schmaltz.

The Process

Today, you’d never encounter cheilev directly in a kosher butcher shop or supermarket. There is a careful process known as nikkur7 (de-veining), where trained experts remove prohibited fats before kosher meat reaches the consumer. This same process also removes another forbidden part of the animal — the gid hanasheh, or sciatic nerve — which the Torah prohibits following Jacob's struggle with the angel.8

While nikkur is halachically permitted and historically practiced, many communities, especially those outside of Israel, refrain from consuming certain hindquarter cuts due to the complexity of the process. This also allows us to mostly avoid doing the complex process of nikkur, although some nikkur is still required to permit the rest of the animal. As a result, cuts such as filet mignon and some sirloin steaks are often unavailable in kosher markets. See Why Can't I Find Kosher Filet Mignon?

Understanding cheilev highlights a core concept behind keeping kosher: holiness is found not only in what we eat, but in the care taken to honor G‑d’s distinctions, down to the smallest details.