What Is Kosher and How Do You Follow the Diet?

Medically reviewed by Karina Tolentino, RD

The term "kosher" refers to food that follows Jewish dietary law. The rules determining whether a food is kosher are called "kashrut." They include requirements for the food substance itself, how it is prepared, and what other foods it is eaten with. Not all people of Jewish heritage or faith eat kosher, but many do.

In this article, learn more about what makes a food kosher or not, including a list of kosher and nonkosher foods.

Kashrut

"Kashrut" is a Hebrew word meaning fit or proper. Food that follows kashrut is considered kosher.

Understanding Kosher Diet and Law in Jewish Tradition

Eating kosher is not just about eating food that is considered safe or clean. It is about devotion to the Jewish religion and following the Torah.

The Torah is the sacred Jewish book of teachings. Kashrut, or Jewish dietary law, is recorded in the Torah, specifically in the books of Leviticus and Deuteronomy.

Jewish people interpret the dietary laws differently; not everyone keeps kosher.

What Makes Food Kosher?

To be kosher, a food (and its preparation methods) must follow a set of dietary rules. Food that is not kosher is called "treif."

Kosher foods are divided into these three areas:

• Meat: Selected birds are kosher, as well as mammals that are cloven-hoofed (have split hooves) and chew their cud.

• Dairy: Dairy products must originate from a kosher animal, and cheeses cannot be processed alongside meat products such as rennet (cow stomach).

• Pareve: Any food that is not meat or dairy, for example, vegetables, fruits, grains, fish, and eggs, is considered pareve.

Numerous rules determine whether a food is kosher or not, but here are some important elements, such as the following:

• Pairing: You cannot eat meat and dairy together or within a certain period of one another. Meat can be paired with pareve, and dairy can be paired with pareve, but they cannot be paired together. Meat and fish (considered pareve) also cannot be eaten together.

• Preparation: There are various rules regarding how food is prepared, ranging from how it is slaughtered to how it is cooked or served. For example, meat must be slaughtered following the principles of "shechita," which includes instant death and no pain for the animal. Another example is using separate pans, utensils, and plates for meat and dairy products.

• Certification: It can be challenging to keep track of kosher requirements. For example, if a fish is filleted, you may be unable to tell what kind of scales it had, or if you buy bread at a bakery, you may not know if they used animal fat in cooking. There are certification programs that can verify whether a food is genuinely kosher or not.

List of Kosher Foods

Below is an incomplete list of kosher foods. Keep in mind that Jewish dietary law is extensive and complex, so more foods than those listed below are kosher.

Certain Meat

You may be wondering what meats are kosher. Mammals must chew their cuds and have cloven (split) hooves to be considered kosher.

Examples of kosher meats include:

• Cow

• Sheep

• Goat

• Deer

• Mountain sheep

• Antelope

Remember that beef (for example) is not necessarily kosher just because it's from a cow. It also must be slaughtered and processed following kashrut.

Certain Poultry

According to kashrut, there are 24 birds that are forbidden to eat. Other birds are assumed to be kosher.

Traditionally, the four most accepted kosher birds are:

• Chicken

• Turkey

• Duck

• Goose

Other birds (such as pigeon or pheasant) may or may not be consumed depending on individual practice.

Certain Fish

Kosher fish must have fins and easily removable scales.

Examples of kosher fish include:

• Salmon

• Tuna

• Cod

• Anchovies

• Herring

• Bluegill

• Mahi-mahi

• Caviar from a kosher fish

Related: The Healthiest Fish to Eat

Eggs

Eggs must come from a kosher bird or fish, and they must not contain any blood spots.

Certain Dairy

Dairy products must come from a kosher animal. Kosher certification is required for cheeses to ensure that nonkosher animal products (most commonly, rennet or certain enzymes) are not added during processing.

Some examples of kosher dairy products include:

• Cow's milk

• Kosher-certified swiss cheese

• Kosher-certified cheddar cheese

• Kosher-certified cream cheese

• Kosher-certified cottage cheese

Breads and Pastries

Bread is an important part of Jewish culture and diet, but it must be made without any dairy-containing ingredients (for example, butter, certain oils, animal fat, or shortening). It also must be made in specially designated pans that aren't used to cook nonkosher foods.

When made in this way, some kosher breads and pastries include:

• Bread loaves

• Rolls

• Challah

• Bagels

• Bialys

• Doughnuts

• Cake

Kosher dedicated bakeries are common because of complications which make it challenging to eat bread products from nonkosher commercial bakeries.

Fruits and Vegetables

Most fruits, vegetables, berries, and grains are kosher in their natural state. They are considered pareve (neutral) and can be paired with either meat or dairy.

Importantly, fruits and vegetables must be inspected for bugs or insects before eating. If they contain bugs, then they are nonkosher and cannot be eaten.

Kosher Salt vs. Regular Salt

Kosher salt is a coarse salt that is made without any nonkosher additives or processing agents, and under the guidance of a rabbi to ensure it remains kosher.

Related: The Healthiest Fish to Eat

List of Nonkosher Foods

Below is a list of some well-known nonkosher foods. There are more foods than those listed below that are considered nonkosher.

Nonkosher (treif) foods include:

• Pig/pork

• Rabbit

• Kangaroo

• Camel

• Twenty-four birds, including hawks, seagulls, ostriches, and vultures

• Shellfish

• Eel

• Catfish

• Caviar from a nonkosher fish

• Bread products that contain dairy

• Cheeseburgers (and other foods mixing meat and cheese)

• Insects or any fruit or vegetable containing insects

• Reptiles

• Amphibians

• Cheeses produced with animal products

• Certain emulsifiers and other processing agents

Keep in mind that some of the kosher foods listed previously may actually be nonkosher due to factors in how they are processed or prepared. For example, if a kosher animal died of natural causes or was hit by a vehicle and considered roadkill, meaning it was not slaughtered according to kashrut, then it would be considered nonkosher.

Kosher Beverages

Like food, beverages must also be made with kosher ingredients and production methods. With processed beverages like soda or wine, it can be hard to track whether it is kosher because there are so many ingredients, so look for kosher-certified products.

Wine must not be processed with nonkosher ingredients, like additives, and production must be supervised by rabbis or sabbath-observing Jewish people.

Everyday Kosher vs. Kosher During Holidays

Eating kosher is different from eating "kosher for Passover."

Passover is an important Jewish holiday that lasts eight days during the spring. During Passover, there are additional Jewish dietary laws. These include:

• Not eating leavened bread products made from wheat, barley, oat, spelt, and rye

• Kitniyot, or not eating legumes (plant foods with stems, leaves, and pods) or pulses (the edible seeds from legumes)

In other words, some breads and other foods considered kosher at other times of the year are not kosher during Passover.

Kosher Labels on Food Packaging: How to Tell

In the modern-day food system, where food can go through lengthy processing, it can be impossible to tell if it is kosher.

For instance, you would need to know what enzymes your cream cheese was produced with, how your beef was butchered, what other products the baker cooks in their pans that also are used to make kosher breads, and more.

This is why kosher certification programs exist. Several agencies perform supervision and testing to guarantee that a product is kosher; this can make keeping kosher much easier.

Look for a "hechsher" symbol on the packaging to tell if a food is kosher or not. This is a rabbinic seal of approval or Kosher certification symbol.

Some popular hechshers look like the following:

• U with a circle around it

• K with a circle around it

• The Hebrew spelling of kosher

• The letter "P" or the words "kosher for Passover"

Related: Why Mourners Place Stones on Jewish Graves

Summary

The term "kosher" refers to food considered fit and proper under Jewish dietary law. The rules governing whether a food is kosher relate to the food itself, how it is slaughtered, processed, cooked, and served, and what it is eaten with it.

Read the original article on Verywell Health.