The Difference Between Kosher and Non-Kosher Food (Part 1)

Kosher food is food that complies with the rules of Jewish religious belief, which make up the main kashrut (the Jewish dietary law). Meat, eggs, dairy and so on all have their Kosher rules. Reasons for non-Kosher food include raw materials from non-Kosher animals, or Kosher animals not properly slaughtered, production by non-Jews, mixing meat with milk/wine/grape juice (and their derivatives), and even using utensils and machines that once held non-Kosher food.

Meat

In Judaism, most Kashrut rules are about animals. The Torah (the first five books of the Old Testament) clearly states which animals may be eaten and which are forbidden.

Slaughter methods compliant with Kosher rules

Jewish law states that Kosher mammals and birds must be slaughtered according to strict guidance, see shechita. Hunting is not allowed; only live capture and slaughter according to the rules. A professional slaughterer, who absolutely never violates the rules, must carefully inspect each slaughtered animal, be highly skilled, and make a single cut of precise depth to the throat, causing the animal to bleed to death. After the animal is killed, it is opened to check whether there are non-compliant parts inside.

Since Jewish law forbids consuming the blood of any animal, all blood and large blood vessels must be removed from the meat. The most common methods are soaking and salting, which can also be done through a special broiling process.

Honey

Honey is compliant with Kosher rules; Israel is alluded to in the Torah as a land of milk and honey.

Eggs

The eggs of Kosher birds are Kosher; for Spanish and Portuguese Jews, if there is blood in the egg white but it can be removed, it is Kosher and edible, but if there is blood in the yolk it cannot be eaten. For German, Polish and Russian Jews, no distinction is made between blood in the white or in the yolk. Unformed eggs may be eaten after the blood is removed as prescribed.

Dairy

The milk and dairy derivatives of most Kosher animals are Kosher. Those from animals mentioned in the Talmud as sick or injured to the point of being invalid are not Kosher.

Cheese

The production of hard cheese usually involves rennet; although rennet can come from plants or microorganisms, most of it comes from the stomach lining of animals, so it may not be Kosher-approved. If the rennet comes from the stomach of a Kosher animal slaughtered according to Jewish rules, it is Kosher. But mixed with milk, it becomes non-Kosher cheese.

Gelatin

Today most KOSHER products use fish gelatin. One issue with gelatin is whether it is parve (a Jewish food containing neither meat nor dairy). Kosher parve "gelatin" comes from vegetable gums, which differ from protein-based gelatin. Other gelatin-like materials include guar gum, locust bean gum, xanthan gum, gum acacia, agar, etc. Recently, such products have been used in prepackaged gelled fruit products to replace animal gelatin. Although most gels are considered non-kosher, some prominent rabbinic authorities point out that when gelatin is processed and chemically altered so that it is no longer meat, such cases may be considered parve and kosher.