The Hebrew word “kosher” means fit or proper as it relates to Jewish dietary law. Kosher foods are permitted to be eaten, and can be used as ingredients in the production of additional food items.
The basic laws are of Biblical origin (Leviticus 11 and Deuteronomy 17). For thousands of years, Rabbinic scholars have interpreted these laws and applied them to contemporary situations. In addition, Rabbinic bodies enacted protective legislation to safeguard the integrity of kosher laws.
The laws of kosher are complex and extensive. The intention of this guide is to acquaint the reader with some of the fundamentals of kashrut and provide insight into its practical application. Given the complex nature of the laws of kosher, one should consult an Orthodox Rabbi whenever an issue arises.
Though an ancillary hygienic benefit has been attributed to the observance of kashrut, the ultimate purpose and rationale is to conform to the Divine Will, as expressed in the Torah.
Not too long ago, most food products were made in the family kitchen, or in a small factory or store in the local community. It was relatively easy to ascertain if the product was reliably kosher. If Rabbinical supervision was required, it was attended to by the Rabbi of the community, who was known to all. Today, industrialization, transcontinental shipping and mass production have created a situation where most of the foods we eat are treated, processed, cooked, canned or boxed commercially in industrial settings, which can be located hundreds or thousands of miles away from home.
What adds further complication is that it is generally not possible to judge the kosher status of an item on the basis of the information provided in the ingredient declaration for a variety of reasons.
First, the product may be made from kosher ingredients, but processed on non-kosher equipment. Second, the USDA does not require the listing of certain processing aids, such as pan liners and oils that serve as release agents. Though not legally classified as ingredients, these items could nonetheless render the product non-kosher. Third, many ingredients can be kosher or non-kosher, depending on their source of origin. For example, glycerin and emulsifiers are made from either vegetable (most likely kosher) or animal oils (most likely non-kosher). Finally, many ingredients are listed only in broad terms, with no breakdown of the many complex components that make up the actual item. For example, a chocolate flavor may contain 50 ingredients, but the ingredient declaration will list this entire complex of ingredients as “flavors”.
Unless a person is an expert in food production, the average consumer cannot possibly make an evaluation of the kosher status, which is why it is important to purchase only those products that have the endorsement of a reliable kashruth agency.
II. Kosher and Non-Kosher Meat, Poultry, and Fish
The Torah states that kosher mammals are those that chew their cud (ruminants) and are cloven-hoofed. The following animal species are among those considered to be kosher: addax, antelope, bison, cow, deer, gazelle, giraffe, goat, ibex and sheep. In addition, meat and poultry require special preparation, which will be discussed below.
The Torah does not enumerate specific characteristics to distinguish permitted and forbidden birds. Instead, it enumerates 24 forbidden species of fowl, while all other birds are considered to be kosher. Nonetheless, for various reasons, in practice we eat only those birds which have an established tradition that the species is kosher.
In the United States, the only poultry accepted by mainstream kashrut organizations as kosher are chicken, turkey, duck and goose.
The Torah establishes two criteria to determine which fish are kosher. The fish must have fins and scales. The scales must be easily removable without damaging the skin. [Generally, scales on kosher fish are either thin, rounded and smooth-edged (cycloid) or narrow segments that are similar to teeth of a comb (ctenoid)]. All shellfish are prohibited. Unlike meat and poultry, fish requires no special preparation. Nonetheless, the fish scales must be visible to the consumer in order to establish the kosher status of the fish. Therefore, filleted or ground fish should not be purchased unless properly supervised, or the fillet should have a skin tab with scales attached to the flesh. Furthermore, purchasing fish in a non-kosher fish store is problematic – even if the scales are intact – because the knives and tables are not kosher, and Rabbinic guidance should therefore be sought.
Rabbinic law prohibits consumption of fish and meat together.
Processed and smoked fish products require reliable rabbinic supervision, as do all processed foods.
III. Meat & Poultry Processing
A. Shechita (Slaughter):
The Torah requires that meat and poultry be slaughtered in a prescribed manner known as shechita. The trachea and esophagus of the animal are severed with a special razor-sharp, perfectly smooth blade, causing instantaneous death with no pain to the animal. Only a trained kosher slaughterer (shochet), whose piety and expertise have been attested to by rabbinic authorities, is qualified to slaughter an animal for kosher consumption.
B. Bedika (Inspection):
After the animal has been properly slaughtered, a trained inspector (bodek) inspects the internal organs for any physiological abnormalities that may render the animal non-kosher (treif). The lungs, in particular, must be examined in order to determine that there are no adhesions (sirchot), which may be indicative of a puncture in the lungs. If an adhesion is found, the bodek must further examine it carefully to determine its kosher status. It should be noted that in addition to fulfilling the requirements of halacha (Jewish law), the bedika of internal organs insures a standard of quality that exceeds government requirements.
C. Glatt Kosher:
Though not all adhesions render an animal non-kosher, some Jewish communities or individuals only eat meat of an animal that has been found to be free of all adhesions on its lungs. “Glatt” literally means “smooth”, indicating that the meat comes from an animal whose lungs have been found to be free of all adhesions. Recently, the term “glatt kosher” is increasingly used more broadly as a generic phrase, implying that the product is kosher without question.
D. Nikkur (Excising):
In some kosher animal species, many blood vessels, nerves and lobes of fat are forbidden and must be removed. There are special cutting procedures for beef, veal and lamb known as nikkur (Hebrew word for “excising” ), which must be performed by a specially trained individual.
The Torah forbids the consumption of the blood of an animal. The two accepted methods of extracting blood from meat, a process referred to as “kashering”, are either salting or broiling.
Meat should not be placed in warm water before it has been “kashered”. Once meat is cooked prior to kashering, it cannot be made kosher.
The meat must first be soaked for a half hour in cool (not ice) water in a utensil designated only for that purpose. After allowing for excess water to drip off the meat, the meat is thoroughly salted so that the entire surface is covered with a thin layer of salt. Only coarse salt should be used. Both sides of meat and poultry must be salted. All loose inside sections of poultry must be removed before the kashering process begins. Each part must be soaked and salted individually.
If the meat or poultry was sliced during the salting process, the newly exposed surfaces of the cut must now be soaked for a half hour and salted as well.
The salted meat is left for an hour on an inclined or perforated surface to allow the blood to flow down freely. The cavity of the poultry should be placed open, in a downward direction.
After the salting, the meat must be thoroughly soaked, and then thoroughly washed to remove all of the applied salt.
According to Jewish law, meat must be kashered within 72 hours after slaughter so as not to allow the blood to congeal. If meat has been thoroughly soaked prior to the 72 hours limit, an additional seventy-two hours time stay is granted to complete the first step of the salting process.
An alternate means of “kashering” meat is through broiling. Liver may only be kashered through broiling, because of the preponderance of blood in it.
Both the liver and meat must first be thoroughly washed to remove all surface blood. They are then salted slightly on all sides. Subsequently, they are broiled specifically on a designated liver-broiling perforated grate over an open fire, which draws out the internal blood. When kashering liver, slits must be made in the liver prior to broiling.
The meat or liver must be broiled on both sides until the outer surface appears to be dry and brown. After broiling, the meat or the liver is rinsed off.
F. The Kosher Butcher:
Years ago, salting of meat and poultry was performed in the home of the consumer. More recently, the kosher butcher performed salting in the butcher shop. Today, the entire process of slaughtering, bedika, nikkur and salting has shifted to the slaughterhouse. This allows for uniform consistency of high standards. Nonetheless, the kosher butcher plays a critical role in distributing the product. The butcher must be a person of integrity and the store should be under reliable Rabbinic supervision.
From the time of slaughter, kosher meat and poultry must be properly supervised until it reaches the consumer. A metal tag called a plumba, bearing the kosher symbol is often clamped on the meat or fowl to serve as an identifying seal of supervision. Alternatively, the meat or fowl is packed in tamper-proof packaging with the kosher logo prominently displayed.
Because kosher meat and poultry have many processing requirements (shechita, bedika nikkur and salting), which must be performed by specially trained individuals, the labor costs associated with kosher meat and poultry are significantly greater. This accounts for the higher cost of kosher meat and poultry.
IV. Caterers, Restaurants, Hotels:
Caterers, restaurants, and hotels must be supervised by a reputable Orthodox Rabbinic authority.
It cannot be assumed that kashrut is maintained simply because a kosher impression is created by an advertisement or by a statement, such as, “we serve a kosher clientele.” Too often, ‘vegetarian’ or ‘dairy’ restaurants are assumed to be kosher and beyond the need for supervision. Unfortunately, this is a prevalent misconception. Fish, baked goods, cheese, shortening, oil, eggs, margarine, dressings, and condiments are among the many foodstuffs requiring supervision in ‘vegetarian’ and ‘dairy’ restaurants. Even those food items that are kosher in their raw states could be rendered non-kosher when prepared on equipment used for non-kosher food. For these reasons, reputable kosher supervision is required.
V. Meat and Milk in the Kosher Kitchen
The Torah forbids: 1) cooking meat and milk together in any form; 2) eating such cooked products, or 3) deriving benefit from them. As a safeguard, the Rabbis extended this prohibition to disallow the eating of meat and dairy products at the same meal or preparing them on the same utensils. Furthermore, milk products cannot be consumed after eating meat, for a period of time. There are different traditions for how long to wait between meat and dairy, but the most prevalent custom is to wait six hours.
Meat may be eaten following dairy products with the one exception of hard cheese that is aged 6 months or more, which requires the same waiting time as that of dairy after meat. Prior to eating meat after dairy, one must eat a solid food, either drink a liquid or thoroughly rinse one’s mouth, and check the cleanliness of ones hands.
Unless one is a vegetarian and meat is totally excluded from his kitchen, a kosher kitchen must have two different sets of utensils, one for meat and poultry and the other for dairy foods. There must be separate, distinct sets of pots, pans, plates and silverware.
B. Washing Dishes:
Ideally, it is best to have two kitchen sinks, one for meat and the other for dairy. If this is not feasible, and one uses one sink for both meat and dairy, dishes and utensils should be placed and washed on a rack, so as not to touch the sink. Separate racks are to be used for meat and dairy use. Care must be taken to make sure that the water should not be allowed to rise to reach the level of the rack, and dishes cannot be soaked in a sink used for both dairy and meat.
The eggs (or other by-products) of non-kosher birds or fish are not kosher. Caviar, therefore, must come from a kosher fish and this requires reliable supervision. Commercial liquid eggs also require supervision. Eggs of kosher fowl that contain a blood spots must be discarded, and therefore eggs should be checked before use.
VII. Shortening and Oil:
Government regulations concerning the labeling of food ingredients have undergone strict changes. Not only must the label specify the type of shortening, i.e., vegetable or animal, but it must declare the actual source as well. Thus, it is commonplace to find mention of cottonseed oil, lard, coconut oil, and other oil sources. The result of this explicit label display is that the consumer can easily detect what is blatantly non-kosher. However, it is important to be aware that the kosher status of a product containing even pure vegetable shortening can only be verified by reliable kosher certification. The reason for this is that manufacturers of vegetable shortening often process animal fats on common equipment. Pure vegetable products may satisfy USDA guidelines for purity, however, in terms of Jewish law, vegetable oil may be non-kosher because it is processed on non-kosher equipment.
Emulsifiers are complex substances that are used in many types of food production. They can perform a number of critical functions, among them acting as a surfactant (reducing the surface tension of a liquid) thus making oil and water soluble. Emulsifiers are critical components in many food items, such as margarine, shortenings, cream fillings, toppings, coffee creamers, whiteners, prepared cake mixes, donuts, puddings, ice cream, frozen desserts, instant mashed potatoes, peanut butter, breakfast cereals, chocolates and candies. Emulsifiers may be listed on the ingredient label as polysorbates, glycerides, mono and diglycerides, sorbitan monostearates, etc. Emulsifiers are produced from either animal or vegetable oil, and emulsifiers require reliable kosher supervision.
A critical sector of the food industry is manufacturers of flavors. Flavors, whether artificial or natural, are components of nearly every product. Flavor production is highly complex and uses raw materials from every imaginable source. Some common kosher sensitive ingredients used in flavors are fusel oil (which may be extracted from grape juice), glycerin and castorium (a beaver extract). Since the ingredient declaration never includes a breakdown of ingredients used in flavors, food items containing natural or artificial flavors require reliable supervision.
X. Fillings and Cremes:
All fillings, cremes, and fudge bases must be certified kosher because they may contain fats, emulsifiers, gelatin stabilizers and flavors.
XI. Breads, Rolls, Challah, Bagels and Bialys:
These basic household staples present several kosher problems and require kosher certification.
Many types of bread are made with oils and shortenings. Basic ingredients of specially prepared dough mixes and dough conditioners are shortenings and di-glycerides. In bakeries, pans and troughs in which the dough is placed to rise and to bake are coated with grease or divider oils, which may be non-kosher. These oils often do not appear on the label. There may also be an issue of other non-kosher products prepared and baked on the same equipment. These are some of the reasons that bread requires kosher supervision.
It is Rabbinically prohibited to produce bread utilizing dairy ingredients. Since bread is frequently eaten at all meals, the Rabbis were concerned that one might inadvertently eat dairy bread with a meat meal. There are two exceptions – if the bread is baked in an unusual shape or design indicating that it is dairy, or if the loaf is so small that it would be consumed at one meal.
Jewish law requires that a portion of batter or finished baked product be set aside for what is known as “challah”’. While any size portion is adequate for challah, it is customary to separate a portion the size of an olive. After separation, the challah is burned. This ritual is obligatory only when the owner of the dough at the time of its preparation is Jewish, and the dough is made from flour of any of the following five grains: wheat, oats, rye, spelt, and barley. In addition, there is no requirement to separate challah if the batter contains less than 2-1/2 pounds of flour. If the batter contains at least 5 pounds of flour, a blessing is recited before separating challah.
If this mitzvah has not been performed in the bakery, it may be performed in the home by placing all the baked goods in one room, breaking open all sealed packaged material, and taking a small piece from any of the baked goods and burning it.
XII. Cake, Pastries and Doughnuts
These products generally contain shortening, emulsifiers, flavors and other kosher sensitive ingredients, and therefore reliable supervision is necessary.
XIII. Dairy Products
Rabbinic law requires that there be supervision during the milking process to ensure that the source of the milk is from a kosher animal. Following the opinion of many rabbinic authorities, OU policy is that in the United States, the Department of Agriculture’s regulations and controls are sufficiently stringent to ensure that only cow’s milk is sold commercially. These government requirements fulfill the Rabbinical requirement for supervision. However, some individuals are more stringent and only consume milk that was produced with full-time supervision. This is known as cholov yisroel.
All cheeses require kosher certification, including hard cheeses (Swiss, cheddar, etc.) and soft cheeses (cottage, farmer, pot, and cream cheese). Rennet, processed from the stomachs of unweaned calves, is often used in the production of hard cheese as a curdling and coagulating agent. Kosher hard cheese is produced with microbial rennet, which is derived from kosher sources. Because hard cheese is typically made with animal rennet, the Rabbinic sages decreed that even when animal rennet is not used, a full-time supervisor must be present to guarantee the kosher integrity of the product. Hard cheese produced with kosher ingredients and a full-time supervisor is known as gevinat yisroel.
Soft cheeses may contain cultures and flavors that are not kosher. Since these products are pasteurized, the integrity of the equipment is an issue as well.
XIV. Pareve Foods:
The adjective ‘pareve’ means that the food item does not contain dairy or meat ingredients, and it was not processed with heat on dairy or meat equipment. Pareve foods are neutral and may be eaten with meat or dairy foods.
OU policy is that dairy or meat items are labeled OU-D and OU Dairy or OU Meat respectively. An item that is labeled OU without a suffix can be assumed to be pareve. Nonetheless, we recommend checking the ingredients listed on the label, since on rare occasions, the OU-D is inadvertently omitted.
According to government standards, any product labeled ‘sherbet’ or ‘fruit sherbet’ must contain milk and is, therefore, not pareve. Water ices may be pareve or dairy, which will be reflected in the OU designation.
Margarine contains oils and glycerides and requires rabbinic certification. Additionally, margarine may contain up to 12% dairy ingredients, and therefore some margarines are OU Dairy while others are pareve.
D, Non Dairy Creamers:
Many non-dairy creamers are, in fact, dairy and bear an OU-D. The government requires that creamers be labeled “non-dairy” if milk derivatives are used instead of whole milk.
XV. Natural and Health Foods
With the proliferation of so-called “Natural” or “Pure” and similarly promoted health food products in the United States, some clarification is in order with regards to their kashrut status. There is a mistaken notion that natural products are inherently kosher. In fact, all non-kosher food items are natural, and therefore natural has no bearing on the kosher status.
XVI. Wines and Grape Products
All grape juice, grape wines or brandies must be prepared under strict Orthodox Rabbinic supervision. Once the kosher wine has been cooked, no restrictions are attached to its handling. Such products are generally labeled “mevushal”.
Grape jam (produced from grape pulp) as well as all varieties of jam and jelly require supervision because they may be processed on non-kosher equipment and may contain non-kosher additives.
Grape jelly is produced from grape juice and can be used only when produced from kosher grape juice under proper supervision.
Natural and artificial grape flavors may not be used unless they are kosher endorsed. Many grape flavors contain natural grape extracts and are labeled artificial or imitation because other flavoring additives are used in the formula.
Liqueurs require supervision because of the flavorings used in these products. In addition, the alcohol base may be wine derived.
For the businessperson or tourist traveling across the United States, kosher certified products are available almost everywhere, even in the smallest groceries in the most remote towns. However, it is much more difficult to obtain reliably kosher certified products in most foreign countries.
A traveler bringing along frozen (TV) dinners where only non-kosher ovens are available for reheating, may use the ovens by covering the frozen package with two layers of aluminum foil. If a microwave will be utilized, then the food must also be double wrapped. Kosher meals should be ordered in advance when traveling by plane, train or ship. These meals are also heated in non-kosher ovens. The employees of the carrier are instructed to heat these meals in the same manner that they were received; totally wrapped in double foil with the caterer’s seal and the Rabbinic certification seal intact. The traveler can ascertain by the intact seals that the dinners have not been tampered. Any dinner, which is not properly sealed, should not be eaten. The kosher certification only applies to the food in the sealed package.
Any other food (rolls, wines or liqueurs, cheeses, and coffee creamers or snacks) served loose by the carrier is not included in the kosher endorsement, unless it is sealed and bears its own separate endorsement.