February 2001 -- Fishing for Answers
Fishing for AnswersHalachic Perspectives on the Kashrus of Fish
by Rabbi Zushe Yosef Blech
Identifying Kosher Fish
The Torah requires that fish have both scales and fins to be kosher. (The Talmud discusses other characteristics distinctive to kosher fish that may be considered in determining the status of a given sample. Avodah Zara 40a.)
The Talmud (Chullin 66b) further teaches us that all fish that have scales also have fins, so in practice kosher fish are identified by their scales. Obviously, crustaceans (such as lobster) and other shellfish (such as clams) are not kosher because they lack scales.
All "scales," however, are not halachically equal. Halacha defines a fish scale as a growth on the side of a fish similar to a fingernail: it must be removable without damage to the skin of the fish.
Sturgeon, although it has primitive, bony plates on its sides, is not kosher because the scales cannot be removed without damaging the flesh. Sharks are similarly not kosher, because their skin is covered with tiny teeth-like armor, which are not considered scales at all.
Although many kosher fish are completely covered with scales, halacha requires only a minimum number of scales to accord a fish kosher status (see Y.D. 83:1). Tuna, for example, have very few scales, yet are nevertheless kosher.
Two additional factors, however, complicate the kashrus of fish. First, a single species of fish may be known by five or more common names, some of which sound like names of known kosher species. "Rock Salmon," for example, is a non-kosher fish (also known as Atlantic Wolfish), and bears no relationship to the common kosher species of true salmon. Furthermore, although halacha requires a tradition for considering birds (and according to many authorities, even animals) as kosher species, no such halachic requirement exists for fish.
Each of the hundreds of species of fish on the market may be evaluated as to its kosher status, even if it is newly discovered. It is therefore critical to evaluate a given species very carefully before judging its kashrus.
Kashrus of Processed Fish
Since kosher and non-kosher fish can be very similar, halacha requires that fish may not be eaten unless they have been inspected to ensure their kosher status. Thus one may not purchase fish fillets (if all of the skin has been removed) without a reliable hashgacha, since the filet is no longer identifiable as a kosher species. Fish roe likewise may also not be used without such supervision (true caviar comes from sturgeon and is never kosher).
There has been much discussion about the kosher status of canned fish (such as tuna and skinless sardines), in situations where the supervision of the cannery is based upon spot checks and each fish is not checked by the mashgiach. Many authorities are reluctant to accept such fish as kosher (see Igros Moshe Y.D. II:8, IV:1).
One possible approach to dealing with processed fish is based upon the ruling of the Shulchan Aruch (Y.D. 83:8), which states that if the flesh of the fish is red then it can be assumed to be from a kosher species.
This ruling assumes that all red-fleshed fish are kosher, an assumption questioned by the Shach (ibid, s.k. 27). While this approach would seemingly solve concerns relating to red fish, modern food technology may have compromised its application.
Much of the fish consumed today is raised on "fish farms," ponds or other enclosed waters where fish are segregated and fed a specific diet. It has been found that if red-pigmented foods are fed to certain fish, their otherwise white flesh develops a reddish color. This is the process that produces "salmon trout," which is a normal trout that has been fed red pigments.
Since this process is known to be effective and common, it is difficult to maintain the halachic stance that all red fish must be kosher.
Preventing Bishul Akum
The rules of bishul akum create another concern about canned fish. Halacha states that a Jew must be involved in the cooking process of many foods, a requirement that is addressed by reliable hashgachos. Unfortunately, most fish canneries are located in parts of the world where full-time (or even significant) involvement by the mashgiach is difficult.
A number of halachic approaches have been explored to address this problem (based upon the method by which the fish are cooked and whether this type of fish is included in the restrictions of bishul akum), but many authorities do not accept canned fish that has not been cooked under reliable hashgacha. To address both of these concerns, many kosher canned fish now bear a specific designation that they have been prepared under full time supervision.
Smoked fish poses another bishul akum concern, one that illustrates how deceptive food terminology can be. One of the general rules of bishul akum is that it applies only to food that is cooked with heat--smoked food is not subject to this restriction (Y.D. 113:13). It would therefore seem a simple matter to certify smoked fish--were it not that the fish is actually baked!
Most commercial smoked fish is actually baked in a large oven, with a small amount of smoke added at the end of the cooking cycle for flavor. The smoking process that is free of bishul akum concerns involves cold smoke--a tedious and expensive process.
Also, fish smoking plants often smoke sturgeon, eel, and other non-kosher fish, making a reliable certification for smoked fish imperative.
Imitations and Derivatives
The Talmud also teaches us that for every non-kosher food there exists an equal and opposite kosher version (Chullin 109b). Modern food technology has indeed given a new twist to this concept. While lobster, shrimp, and crab may not be kosher, imitation versions of these non-kosher staples can now be obtained with excellent hashgacha.
Surimi is an ancient Japanese process by which minced fish is converted into a protein base and used to produce a variety of foods. Today, kosher surimi (produced under supervision, of course) is used to produce imitation crab legs, lobster and shrimp--and is deemed true to the flavor of the real thing!
Another interesting application of ichthyology in modern food technology relates to fish oil. In many parts of the world, fish oil is used as we use vegetable oil--to make margarine, for cooking, etc. The fish used to produce fish oil are certainly not inspected by a mashgiach, and such oils are generally not accepted as kosher. While this use of fish oil has not yet come to North American shores, a modern version of a childs nightmare has.
One time-honored fish oil is cod liver oil, a rich source of vitamins. Its use has become less common due to improved diet and vitamin fortification of foods. Research now shows, however, that certain fatty acids, called Omega-3 fatty acids, found in other types of fish oil may have significant benefit in reducing heart and other health problems. While these often come from kosher fish, one should consult a halachic authority to determine their appropriate use.
Derivatives of fish often wind up in unexpected places--both ancient and modern--and may pose both health and halachic concerns. On one hand, classic Worcestershire sauce contains anchovies as part of its flavoring base, which raises issues as to its acceptability in flavoring meats (fish may not be eaten together due to health-related concerns discussed in the Talmud).
On the other hand, modern food technology has developed a new way of producing gelatin. Gelatin is an animal-derived protein, used as the base of gel-type deserts and gummy-type candies and as a gelling agent in Swiss-style yogurt.
It is always interesting to note how the scrupulous observance of halacha affects all aspects of our lives. It has long been a custom to eat gefilte fish on Shabbos. Although the gastronomic considerations of this delicacy may seem the most obvious, the real reason for this custom lies in halacha.
Shabbos is a day of rest where many types of labor are prohibited. One of the activities in which one may not be engaged on Shabbos relates to the separation of chaff from grain, which is known in Hebrew as borer. This restriction extends to many types of separation, and the rules governing which types are permitted are quite complicated.
Borer often becomes a problem while eating fish, since fish is often served whole and the bones are not removed before serving. In order to avoid this concern, a custom developed whereby the fish was filleted, ground, and stuffed back into the skin and then cooked.
The resulting delicacy--gefilte (stuffed) fish--was then presented at the Shabbos table in a beautiful presentation--ready to be eaten without worrying about borer! Even though we often eat gefilte fish without the skin, the origin of the custom is an apt testimonial to the care that the Jewish people have historically taken to abide by all mitzvos.
The Talmud (Shabbos 156a) tells us that the Jewish people can merit being lifted above the celestial influences that effect the ordinary functioning of the world.
May it be in the merit of customs such as gefilte fish and the strict adherence to kashrus issues that fish present that we grow in the holiness that the Jewish people represent.
Fish and Purim
Adar is considered under the Mazal (astrological sign) of Dagim (Pisces)--the fish. Fish are considered a symbol of blessing and abundance. Yaakov Avinu used fish as an aphorism for blessing and plenty--a prediction clearly borne out by the miracle of Purim.
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