“Kosher” is a term used to describe food that complies with the strict dietary standards of traditional Jewish law.
For many Jews, keeping kosher is about more than just health or food safety. It is about reverence and adherence to religious tradition.
That said, not all Jewish communities adhere to strict kosher guidelines. Some individuals may choose to follow only certain rules — or none at all.
This article explores what “kosher” means, outlines the main dietary guidelines, and gives the requirements that foods must meet to be considered kosher.
What does “kosher” mean?
The English word “kosher” is derived from the Hebrew root “kashér,” which means “to be pure, proper, or suitable for consumption”.
The laws that provide the foundation for a kosher dietary pattern are collectively referred to as “kashrut” and are found within the Torah, the Jewish book of sacred texts. Instructions for practical application of these laws are passed down through oral tradition.
Kosher dietary laws are comprehensive and provide a rigid framework of rules that not only outline which foods are allowed or forbidden but also mandate how permitted foods must be produced, processed, and prepared before consumption.
Summary: “Kosher” is a term used to describe foods that comply with dietary guidelines set by traditional Jewish law. These laws determine which foods may be consumed and how they must be produced, processed, and prepared.
Certain food combinations are strictly forbidden
Some of the main kosher dietary guidelines ban certain food pairings — particularly the pairing of meat and dairy.
There are three main kosher food categories:
- Meat (fleishig): mammals or fowl, as well as products derived from them, including bones and broth
- Dairy (milchig): milk, cheese, butter, and yogurt
- Pareve: any food that is not meat or dairy, including fish, eggs, and plant-based foods
According to kosher tradition, any food categorized as meat may never be served or eaten in the same meal as a dairy product.
Furthermore, all utensils and equipment used to process and clean meat and dairy must be kept separate — even down to the sinks in which they’re washed.
After eating meat, you must wait a designated amount of time before consuming any dairy product. The particular length of time varies among different Jewish customs but is usually between 1 and 6 hours.
Pareve food items are considered neutral and may be eaten alongside either meat or dairy.
However, if a pareve food item is prepared or processed using any equipment used to process meat or dairy, it is then reclassified as meat or dairy.
Summary: Kosher guidelines strictly prohibit the pairing of any meat and dairy product. This also means that all utensils and equipment used to prepare meat and dairy must always be kept separate.
Only certain animal products are permitted
Many kosher rules address animal-based foods and the ways they are slaughtered and prepared.
Dairy is treated as a separate entity and should never be consumed or prepared alongside meat or meat products.
Fish and eggs are considered pareve and have their own sets of rules too.
The term “meat” in the kosher context generally refers to edible flesh from certain types of mammals and fowl, as well as any products derived from them, like broth, gravy, and bones.
Jewish law states that for meat to be considered kosher, it must meet the following criteria:
- It must come from ruminant animals with cloven — or split — hooves, such as cows, sheep, goats, lambs, oxen, and deer.
- The only permitted cuts of meat come from the forequarters of kosher ruminant animals.
- Certain domesticated fowl can be eaten, such as chicken, geese, quail, dove, and turkey.
- The animal must be slaughtered by a shochet — a person trained and certified to butcher animals according to Jewish laws.
- The meat must be soaked to remove any traces of blood before cooking.
- Any utensils used to slaughter or prepare the meat must be kosher and designated only for use with meat and meat products.
The following types of meat and meat products are not considered kosher:
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- meat from pigs, rabbits, squirrels, camels, kangaroos, and horses
- predator or scavenger birds, such as eagles, owls, gulls, and hawks
- cuts of beef that come from the hindquarters of the animal, such as flank, short loin, sirloin, round, and shank
Dairy products — such as milk, cheese, butter, and yogurt — are permitted, although they must adhere to specific rules to be considered kosher:
- They must come from a kosher animal.
- They must never be mixed with any meat-based derivatives, such as gelatin or rennet (an animal-derived enzyme), which is often the case with hard cheeses and other processed cheese products.
- They must be prepared using kosher utensils and equipment that has not previously been used to process any meat-based product.
Fish and eggs (pareve)
Although they each have their own separate rules, fish and eggs are both classified as pareve, or neutral, which means they do not contain milk or meat.
Fish is considered kosher only if it comes from an animal that has fins and scales, such as tuna, salmon, halibut, or mackerel.
Water-dwelling creatures that don’t have these physical features — such as shrimp, crab, oysters, lobster, and other types of shellfish — are not permitted.
Unlike kosher meat, fish don’t require separate utensils for their preparation and may be eaten alongside meat or dairy products.
Eggs that come from kosher fowl or fish are permitted as long as they don’t have any traces of blood in them. This means that each egg must be inspected individually.
Like fish, eggs may be eaten alongside meat or dairy.
Summary: Kosher guidelines limit the consumption of animal-based foods to specific animals and cuts of meat that are slaughtered and prepared in a particular manner.
Guidelines for plant-based foods
Like fish and eggs, plant-based foods are considered pareve, or neutral, meaning they do not contain meat or dairy and may be eaten with either of those food groups.
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These foods also have their own set of kosher guidelines — especially regarding how they’re processed — although these guidelines are somewhat less restrictive than those for meat and dairy.
Grains and bread
In their purest form, grains and grain-based foods are considered kosher. However, certain processing methods may ultimately deem them not kosher.
Processed grain products such as bread may not be kosher as a result of the equipment on which they’re processed or the ingredients used.
It is common for some bread to contain oils or shortening. If an animal-based shortening is used, the bread may not be considered kosher.
Furthermore, if baking pans or other equipment are greased with animal-based fats or otherwise used to cook any meat- or dairy-containing dish, the end product is no longer kosher.
Because these types of processing methods are not typically disclosed on a standard nutrition or ingredient label, bread and other grain products must be certified kosher to ensure that the food complies with all relevant guidelines.
Fruits and vegetables
Like grains, fruits and vegetables are kosher in their unprocessed form.
However, because insects are not kosher, fresh fruits and vegetables must be inspected for the presence of insects or larvae before sale or consumption.
Furthermore, fruit and vegetable products that are produced using non-kosher equipment, such as anything that processes milk and meat, are not kosher.
Nuts, seeds, and oils
Generally speaking, nuts, seeds, and the oils derived from them are kosher.
However, the complicated processing of these foods often renders them non-kosher as a result of cross-contamination of equipment also used to process meat and/or dairy products.
Many vegetable and seed oils undergo several complicated steps before they’re considered edible. Each of these steps must be closely monitored to ensure adherence to kosher guidelines.
Thus, to be completely certain the oils you’re using are kosher, it’s best to check the label for certification.
Like foods, wine must be produced using kosher equipment and ingredients to be deemed kosher. This includes any tools used to harvest and prepare the grapes for fermentation.
However, because wine is significant to many Jewish religious occasions, stricter rules are imposed.
The entire kosher wine production process must be carried out and supervised by practicing Jews. Otherwise, the wine cannot be deemed kosher.
Summary: Most plant-based foods are considered kosher. However, they may lose this status if they’re processed or prepared using non-kosher equipment.
Different rules apply during Passover
Additional kosher dietary restrictions apply during the religious holiday of Passover.
Though there is some variation in adherence to Passover dietary guidelines, all leavened grain products are traditionally forbidden.
These foods are collectively referred to as “chametz” and include the following grains:
That said, some of these grains may be permitted as long as they haven’t been in contact with any moisture longer than 18 minutes and do not contain any added leavening agents, such as yeast.
This is why matzo, a type of unleavened flatbread, is not considered chametz — even though it is traditionally made from wheat.
Summary: During Passover, all leavened grain products are forbidden. However, unleavened bread, such as matzo, is allowed.
How does certification work?
Because of complex modern food production practices, ensuring that the foods you’re eating are kosher can be very challenging.
That’s why systems are in place for certifying specific food products.
Foods certified kosher feature a label on their packaging indicating that they’ve met all the requirements.
There are dozens of different kosher labels, many of which come from different certifying organizations. If food is certified for Passover, this will be indicated with a separate label. The labels may also indicate whether a food is a dairy, meat, or pareve.
If you’re trying to adhere to kosher dietary guidelines, it’s best to choose only foods with these labels to avoid accidentally eating something non-kosher.
Summary: If you keep kosher, be sure to look for appropriate labels when you shop. Kosher foods often feature a certification to guarantee they have met all the requirements.
“Kosher” refers to a Jewish dietary framework for food preparation, processing, and consumption.
Though variations exist, most guidelines forbid pairing meat and dairy and allow only certain animals to be eaten.
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Foods not considered meat or dairy are generally accepted, provided they’re produced using kosher equipment and practices.
Additional rules may be imposed during religious holidays.
Because of the complexities of modern food production, it can be difficult to know whether many processed foods are kosher. To avoid any missteps, always look for kosher certification labels.