Kosher Food Laws
Jewish food laws, called kashrut, set specific rules for what Jews can eat. These rules are based on religion and history.
Land animals must have cloven hooves and chew their cud; fish must have fins and scales; shellfish are not allowed.
Many kosher observers will only eat foods with reliable Orthodox certification or from supermarkets that offer this label. Others are more lenient.
Meat
Jewish dietary laws prohibit the eating of animals that do not produce milk, such as pork. Other foods that are forbidden, according to kashrut rules, include blood, the sciatic nerve and the mixture of meat and dairy products (with the exception of fish). These food groups must be kept separate, so kosher-observant Jews have two sets of dishes and utensils, one for dairy and the other for meat.
The majority of Jewish people who keep kosher eat a diet that is largely vegetarian, with some fish and chicken added in. The rabbis who oversee the Jewish religion have established strict rules about what can and cannot be eaten, including the slaughter of animals under precise conditions and the separation of meat from dairy products.
Many foods must be kosher-certified, and the kosher symbol is often found on foods in supermarkets. This symbol indicates that the product has been inspected by a rabbi or other rabbi trained in keeping kosher, and meets certain criteria. The rabbis who inspect and certify a product or restaurant are known as mashgichim.
Some meat must be labeled as “kosher,” meaning that it has been slaughtered under strict rabbinical procedures, and that there are no bones in the animal. Also, meat must be cooked and seasoned according to certain guidelines. It is important that a mashgiach supervise the preparation of any meat-based dish, and ensure that all equipment used has not been used to prepare non-kosher products.
Pareve foods are neither dairy nor meat, and include such items as eggs, vegetables, fruits, nuts, fish and some wine. There are a number of rules that govern the preparation of these foods, including that they be insect-free and grown in the Land of Israel.
Dairy
All milk, butter and cheese in Jewish tradition must come from kosher animals. In addition, all ingredients and equipment used to produce these items must be kosher, too. It is also important that no meat or dairy be consumed together, even if they are from different animals (except for gelatin, which is made from a non-dairy source).
To make wine kosher, the grapes must be grown, harvested and prepared according to a set of rules. Similarly, all equipment used to make wine must be kosher. It is important to note that a kosher winery should be certified by a reputable rabbi to ensure that all halachos governing the process are followed.
Other food items that must be kosher include eggs, pasta and packaged foods such as soup, coffee and cookies. It is important for observant Jews to wait a certain amount of time before consuming any dairy products after eating meat and to eat meat before consuming eggs, fish or other seafood.
Observant Jews are also careful about handling foods that are considered Pareve, meaning they don’t contain meat or dairy. They must use separate utensils, cook and clean in different rooms and not mix these foods or eat them with each other. They must also wash their hands before and after handling these foods.
The most common Pareve food is milk, though kosher chocolate must be certified to be so. The kosher laws relating to these foods can be complex, and individuals should always consult their rabbi before making any decisions about what they can and cannot eat.
Fish
Jewish law forbids eating certain mammals, birds and fish. The mammals that Jews may eat must have cloven hooves and chew their cud; they cannot be pigs (Leviticus 11:21). Birds that are kosher include geese, ducks, quail and pheasants. The fish must have fins and easily detachable scales. That excludes sturgeon and its precious roe, caviar; it also includes cod, haddock and bream. All shellfish, including oysters and mussels, are non-kosher.
Mammals and birds that are kosher must be slaughtered in accordance with Jewish law, using a method called shechita; blood must be drained from meat, and all organs must be free of disease and flaws before the animal is eaten. Jews must not eat insects, except for a few types of locusts, on which most communities have no clear tradition. Rodents, reptiles and amphibians are forbidden as well.
Pareve foods are those that contain neither meat nor dairy products, such as kosher fish, eggs from permitted birds and grains, vegetables and other edible plants. People who are kosher do not mix these with meat or dairy, and they must keep them separate from each other. They must use separate utensils, cutlery and dishes for meat and milk and wash them separately. In a kosher kitchen, there should be a dedicated refrigerator for meat and a designated area for milk, to prevent cross-contamination.
Wine must be kosher, and all equipment used to grow, harvest and prepare grapes should be kosher as well. In addition, some fruit drinks and flavored beers are made with grape products, and some baking powders and other foods contain bull’s blood for coloring or isinglass, which comes from a sturgeon. Those who are kosher must also avoid using products made with non-kosher oil or fats and must ensure that they do not touch meat or dairy utensils with their hands, which may transfer residue.
Eggs
There are a lot of kosher rules that address the slaughtering of animals and their preparation as food. Then there are the laws addressing dairy and fish, plus other foods. Some of these laws are based on biblical commandments, while others are rabbinical. There are also rules governing how certain animals are slaughtered and how utensils and equipment used in cooking meat and dairy are kept clean. Other kashrut rules address foods that are neither meaty nor dairyy, known as pareve. Eggs, fruits, vegetables, and grains are considered parve. These foods may be mixed with and eaten with both meaty and dairy products, but must be prepared by utensils and equipment that are free of meat or milk.
In a kosher kitchen, eggs are opened in a glass bowl to check for blood spots. Any egg with a blood spot is not kosher and must be discarded. A similar procedure is used for liver, which must be drained of blood before being eaten.
A person keeps kosher by following the commandments of the Torah and the teachings of the Talmud. Many rabbinical organizations certify products, manufacturers, and restaurants to be kosher. They will often put a widely-accepted symbol on the product, which is called a hechsher. These symbols can be spotted easily on food labels throughout the United States.
The most important kosher rule is that Jews may only eat animals and birds that have been slaughtered in a specific manner, called Shechitah. It is a highly-trained process carried out by a trained individual, called a Shochet. This method of slaughter has been shown to be humane and has significant health benefits for the animal. The kosher status of the slaughtered animal or bird is transferred to its flesh, fat, organs, and eggs. It is also transferred to any foods made from these forbidden animals or their parts, such as milk, eggs, and rennet (the enzyme used to harden cheese).
Wine
As wine is a staple in Jewish culture, it’s no surprise that the beverage has its own rules regarding koshering. Generally, only practicing Jews may touch the wine and equipment from the moment it arrives at the winery, all the way to the final product being bottled and shipped. The same applies to any other liquid grape products such as grape juice and wine vinegar. Similarly, any additives and fining agents used in wine making must be kosher. These items include things like gelatin (animal derivative), casein (dairy derivative) and isinglass (fish product). Fortunately, this restriction doesn’t interfere too much with the quality of wine, and it’s fairly easy to find kosher wines from most large producers, including some that are organic or biodynamic.
Many people think that it’s necessary to have a Rabbi bless the wine in order for it to be kosher, but this is incorrect. In fact, Silverman’s responsum makes it quite clear that most American wines are already kosher by traditional halakhic standards. The only exception is if wine is made by non-observant Jews, which is quite rare.
Another important aspect of kosher wine is that it must be mevushal, or cooked. This is because the rabbis believe that wine once was used in idolatrous ceremonies, and they wanted to ensure that no observant Jew ever drinks wine that had been touched by pagan worshippers. The rabbis also believe that boiling the wine makes it unfit for idolatrous use and, therefore, keeps it kosher. This view is widely accepted among Orthodox Jews, and even some Conservative rabbis follow it. However, some Conservative synagogues are still reluctant to serve only mevushal wine, so they choose to only buy kosher wines that have been verified as kosher by a reliable authority.