What Is Treif?

The word treif is a Yiddish word that refers to any food that is deemed unkosher (i.e. forbidden under Jewish law). The word is derived from the Hebrew word treifah (or terefah) which means something that is torn or mangled. The term was originally used to refer to any meat or animal carcass that had not been slaughtered in accordance with Kosher law. Over the years, the word has come to be used as a common colloquialism for any food that isn't kosher. To best understand what treif is, a full understanding of a kosher diet is needed.

What Does Kosher Mean?

As described in the Bible (Leviticus 11 and Deuteronomy 17), kosher food is food that is prepared according to Jewish dietary laws. Not all Jewish sects and individuals follow these laws and eat kosher. The rules, and subsequent interpretations, are extensive and complex. In part, they state: 

• To qualify as kosher, mammals must have split hooves and chew their cud (e.g. cows, sheep, and goats are kosher but pigs are not). 
• Fish must have fins and removable scales (which excludes shellfish, catfish, eels, shark, and many others).
• Only certain birds are kosher, mainly excluding birds of prey. 
• Meat and dairy products may not be cooked or eaten together.
• Animals must be ritually slaughtered in a prescribed manner.

Keeping Meat and Dairy Separate

The prohibition on combining meat and dairy is an important rule in Judaism and one that impacts the eating habits of observant Jewish people in a more direct and ongoing way than do rules that merely prohibit certain foods.

In addition to avoiding dishes where meat and dairy are combined, Jewish people following kosher guidelines are generally required to keep separate sets of plates, eating utensils, and cooking tools—one set for cooking and serving meat and another set for dairy. The two sets also need to be stored separately. 

Furthermore, to ensure adherence to the rule, Jewish people are required to wait a certain amount of time between eating meat and eating dairy, with the exact duration varying according to interpretation as well as whether one eats meat before dairy or dairy before meat. According to some interpretations, poultry is not considered meat and can therefore be consumed with dairy.

Kosher Slaughtering Requirements

Jewish law and tradition prescribe the exact manner in which animals are to be slaughtered in order for the meat from their carcasses to be considered kosher. These rules specify the type of knife to be used, the specific location on the animal's body that must be cut, and even what type of cutting motion may be used, among many other requirements. 

For example, the knife must be sharp and at least twice as long as the animal's neck. The blade must be straight rather than serrated (due to the fact that a serrated blade is likely to tear the flesh rather than cutting it cleanly). The cut itself must also be continuous, with no pause or back and forth motion. The goal is to cause the animal to lose consciousness and die with as little pain and suffering as possible.

Any deviation from these rules will render the animal unkosher. Specifically, animals that are slaughtered in a manner contrary to Jewish law are considered to be carrion, the equivalent of animals that died on their own or were killed by other animals (i.e. clawed, torn apart, or treif). 

Jewish law also forbids the consumption of blood in any form. This means that for an animal to be slaughtered properly, it must have all its blood completely removed from the body within a certain amount of time. This is accomplished first by physically draining the blood through the initial incision at the neck. Then, the carcass is butchered so as to remove the major blood vessels, and finally, it's treated with an application of salt in a manner designed to extract any residual traces of blood from the meat.

Additionally, kosher law prohibits any form of stunning of the animal prior to slaughtering it. This means that any of several modern-day techniques for rendering an animal unconscious before slaughtering it are deemed to be unkosher, causing the carcass and its meat to be considered treif.