New York – Fish and Worms: Lingering Kashrus Controversy Takes Center Stage Again


    New York – There has been, of late, a huge debate in the Orthodox Jewish world regarding the permissibility of certain types of fish that are infested with worms. Some may dismiss this as an old story—but it is not. Much research has been done for this article, and a video will soon be made available.

    Some rabbis say that the worms under discussion are kosher (as long as they do not actually leave the fish). Other rabbis are adamant that these worms are, in fact, completely forbidden. None deny, however, that these particular worms are found in otherwise kosher fish—and they are found in abundance.

    The particular type of worm in question is called Anisakis. Those who say that it is permitted believe that the worm reaches its recognizable form within the flesh of the fish itself (“Mineih Gavlei,” in the words of the Talmud, Chullin 67b), rather than having entered the fish from the outside. Those rabbis who forbid it claim that the Anisakis worm originates outside the fish and goes to the stomach of the fish; from there, apparently, the worm will migrate to the edible flesh of the fish unless the fish is immediately gutted or frozen after being caught.

    The lineup of rabbis on each side, thus far, is quite impressive. Forbidding it are Rabbi Gershon Bess from Los Angeles and the top poskim of Israel—Rav Elyashiv and Rav Vosner of Bnei Brak. Permitting it thus far are Rabbi Yisroel Belsky of the OU; Dayan Yechezkel Roth, the former Satmar Rebbe’s dayan; and Rav Shlomo Miller of Lakewood and Toronto.

    But does everyone agree to the facts behind the issue—before we get to the discussion of the halachah? To personally ascertain what the facts are in regard to this parasite, while in Eretz Yisrael for a yahrzeit this author spent a day at the Machon l’Mitzvos ha’Tluyos BaAretz in Beit Uzziel. The machon is under the direction of Rav Shneier Zalman Revach. It is a fascinating place, with microscopes that have a computer interface, special light boxes with both fluorescent and ultraviolet bulbs, and many roomfuls of seforim and responsa that the machon has published. The machon is housed within a revitalized religious moshav that was established at about the same time as the founding of the State of Israel.

    Under a light at the machon, we proceeded to pull out numerous Anisakis worms from different types of fishes. After seeing these worms firsthand and where they are located, both in the fresh fish and on tapes and photos from the boats, it is vividly clear that the worms found in the flesh actually have migrated from the stomach—meaning that they have been ingested by the fish from the outside. (I pulled out one of those worms myself; indeed, a test tube filled with spiraled-up Anisakis worms pulled out during my visit lies in my front pocket as I write this article.)

    After the fish have been partially cleaned out or gutted, there are still dark portions of the gut remnants that are attached to the inside part of the stomach’s flesh. Worms that are there cannot go back into the no-longer-existent gut. They therefore worm their way into the flesh of the fish. Many of the worms are fully through; some are halfway through, some three quarters. It is all very interesting (and all very gross).

    This being the case—that the origins of this parasite and the manner in which it enters the fish is now known—the position of those that permit the consumption of fish infested with these worms seems to be quite tenuous.

    There is another issue, too. Even if the worms would be considered kosher, the halachah states that if someone is personally disgusted by the consumption of the worms then it is forbidden to eat them.

    One might have been tempted to read the Shulchan Aruch as permitting even the Anisakis worm. How so? The Shulchan Aruch (Y.D. 84:16) rules that worms that are found in the mei‘ayim (gizzards) of the fish are forbidden; if they are found in between the flesh and the skin or in the flesh, they are permitted. There seems to be a statement here that all worms found in the flesh are permitted. However, if one actually saw the worm proceed from the gizzards into the flesh, then clearly the Shulchan Aruch would not have permitted such a case.

    Some maintain that the Shulchan Aruch’s wording seems to be stating categorically that worms do not migrate from the gizzards to the flesh. Because if they did migrate in such a way, the Shulchan Aruch would not have given tacit permission to consume worms in the flesh. Since we do not at the drop of a hat say “nishtaneh ha’teva”—nature has changed—in regard to halachah, some maintain that we may still follow the ruling that worms found in the flesh of the fish are permitted.

    Rabbi Revach maintains that the issues regarding the kashrus of the Anisakis worm have no bearing on whether one says that nature has changed. He says that the Shulchan Aruch was only referring to a type of worm that is found in the flesh—not one that migrates there afterward because of faulty fish processing. The fault in the fish processing lies in only partially cleaning the fish. When we partially clean the gizzards, but do not make sure that the gizzard remnants are all clean, the worms located there could migrate into the flesh. In Talmudic times, Rabbi Revach maintains, it is likely that homemakers thoroughly cleaned out the gizzards themselves.

    Is it possible for those who wish to avoid eating these worms still it the fish? Can the fish be cleaned? Yes. The seasoned inspector can look at a completely skinned fish in 65 seconds if using a light box. Red fish, however, would require an ultraviolet light and need about 90 seconds to inspect properly.

    The title of this article is “Fish and Worms: The Bottom Line.” What, then, are the conclusions of this article?

    Before we get to that, let’s go over a few points:

    1. As of this writing, the major kashrus agencies in America are not yet committed to ensuring that our fish are free from the Anisakis worm.
    2. It is this author’s contention that anyone who is shown the fish gizzards with the worms, the non-frozen fish that is partially gutted, and the fish on a light box will be conclusively convinced that these worms are not kosher.
    3. Some species of fish, and fish from certain countries, simply do not have the Anisakis worm. This is either because the waters do not have it or because the fish is frozen so quickly after the gizzards have been removed that the worm has no chance of migrating.

    Below is the current status of each type of common fish regarding Anisakis infestation, as of this week.

    Tilapia fillets have no Anisakis (even those from China).

    Hake fillets from Argentina: without skin, they have no Anisakis; those with skin are problematic. Hake fillets from China, even without skin, are problematic.

    Halibut (from all countries) must be roughly scraped and then thoroughly cleansed.

    Pollack from China are infested. With skin, they may not be used; fillets without skin must be inspected on a light box.

    Tuna cuts and slices are free of Anisakis.

    Mackerel fillet sides must be scraped and thoroughly cleansed.

    Herring fillet sides must be scraped and thoroughly cleansed.

    Norwegian and Chilean salmon
    are free of Anisakis but may have external lice. The fillets must be defrosted and rinsed, and the skin must be scraped or brushed. Chinese, American, Canadian, and Japanese salmon fillets may not be used without inspecting on a light box. Farmed salmon in the U.S. is okay.

    Sardines from Morocco are okay. All others must be scraped, brushed, and washed off thoroughly.

    Skinless flounder fillet from the Netherlands is free of Anisakis. Flounder from China must undergo examination on a light box. Flounder with skin from China is unusable; from the Netherlands, it must be defrosted, rinsed, and brushed to remove external lice.

    There are other types of less common fish as well; please inquire about them.

    Rabbi Hoffman may be reached at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

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    1. This is all interesting but 99 percent of frumme yidden are not going to carry around a pocket guide to each type of fish and what kind of parasites it might be carring on a given day. We will find a reliable fishmonger and buy from him or her and assume they will check with the rabbonim if there are any questions. I wouldn’t trust any local rav to have a clue on what is or is not mutar regarding these matters.

    2. Based on what are the differences of eating different types of fishes? Probability? How does the halacha work with Oyrayta prohibitions and probability? Thanks for the info.

    3. 1) I as a mashgich I sat with rabbi revach by a meeting in b”p & most rabonim disagreed with him + Rabbi U. Ekstein disagreed with him by a sheir @ a stolin shoul in b”p
      2) I was alreay in china for fish there is no pollok (flaunder) fish from china it comes from alaska & only worked out in china.
      3) It’s against d silchun uruch so its apikorsis !
      sory for my english !!!

    4. A simple parasitology course would serve better than Halachic arguments. Simple life cycle: Marine mammals release eggs in their feces. Eggs hatch in the water into larva which are then eaten by crustaceans. When these crustaceans are eaten by certain other marine mammals, the larva try to get into the stomach lining and mature into adults. Humans can then eat these marine species.

    5. The basic premise of this article is illogical. It is clear that there are aniskasis worms in some fish that have properly cleaned innards, and that those worms are mutar. This is evidenced from the psak of the shulchan aruch permitting worms in the flesh and the custom of eating fish with aniskasis worms for hundreds of years. The article claims (and it is scientific fact) that the origin of all aniskasis worms at some point in time was the gizzards. This shows that worms that have moved from the gizzards (from a scientific perspective, not a halchik persepctive) are muttar. Yet at the same time, it claims that some fish that did not have their gizzards removed properly are asur, because the worms moved from the gizzard after being caught! Makes no sense!

    6. #1 – ok heres the deal. Whatever G-D had in mind for you he will continue to do with you as you are not interested in doing more for him. Whatever you do in your house you can continue to do but of course if through you your family members are in fact eating worms they will have you to blame for whatever comes becasue of this – here or in the next world. So I feel really bad for you that you went through typing your foolish thoughts.

    7. While i cannot comment on the Halachic implications of Rabbi Hoffman’s research and leave it to further analysis by the recognized poskim, i think the flippancy displayed by shaul from monsey fits in very well with his repeated declarations elsewhere on this site. If someone has no ability to show the least bit of rachmonus for a fellow Jew going through terrible persecutions, why should the care about kashrus beyond what is required for their community standing?

      • Coming from someone who cares more about bugs in water and sheitel hair than young chareidim being destroyed by predators and the rabbonim that cover for them, your comment makes perfect sense.

        As for Rubashkin, I hope he gets the lightest sentence possible – time served. But I would feel his chances for that would be better if he showed remorse and cooperated with the feds in making reparations, show some contrition. His approach did him in far more than the cadre of co-conspirators (PETA, felafel, ICE, water, the judge, the jury, the unions, the boogeyman)

    8. May I suggest a simple reading of this week’s parsha, Kedoshim. The Torah says kedoshim tiheyu, you should be holy. Holy? How? So the Torah tells you how. Be careful about civil offenses, stealing, lying, robbing, cheating your customers. And when is Kedoshim read? During Pirkei Avos learning weeks. Pirkei Avos which teaches us good character traits between people. Oh wow, so being holy doesn’t come from putting on irrational stringencies on things? You mean that if I carry my lox and strawberries to my neighbor for sholosh seudos on Shabbis in Boro park I’m not sinning? But if I take him for a financial ride or pull a fast one on my insurance company them I am sinning and I’m not holy? And here I always thought that being holy means not carrying in an eruv or not eating lox. Oh well, live and learn.

      • Really? How do you get that from the parsha? Does it deal only, or even primarily, with civil offenses? No, it doesn’t. “Kedoshim tihyu” follows directly from the list of arayos and avoda zara, and proceeds directly to the following list: kibbud av va’em, shabbos, avoda zara, korbanos, nosar, pigul, then it lists some bein odom lachavero for ten pesukim, and back into kilayim, arayos, orloh, neta reva’i, kashrus, divination, pe’os, beard, seret lonefesh, tattoos, more arayos, shabbos, mikdosh, more avoda zara, a few more bein odom lachaveros, and then a long repetition of the avoda zara and arayos lists from the previous parsha. Now you tell me what a “simple reading” of kedoshim tells us about how to be holy.

    9. Yay – another fish story.
      Seriously, so people really feel such a lacking in their own lives that they need to tell others that they are doing something wrong??

    10. I’m no expert, but, in my opinion, the article provides insufficient information for me to draw any conclusion.

      The author states, but doesn’t explain how: “After seeing these worms firsthand and where they are located, both in the fresh fish and on tapes and photos from the boats, it is vividly clear that the worms found in the flesh actually have migrated from the stomach”. The author repeats this as a contention in the summary at the end of the article (#2).

      But, just seeing the worms and their location in the fish isn’t in and of itself proof of their origin. What is so convincing about the worms and their location that they were ingested? Couldn’t their presence in the stomach be explained as one of multiple “migrations” (having migrated *to* the stomach at one point and then, later, having migrated *from* the stomach)?

      I’ll be on the alert for clarifications from the OU on the matter, if they choose to issue a statement on it.

      • Exactly. And to the best of my knowledge, the author makes a serious error. He assumes that the worms migrate from the gut to the flesh after the fish is caught and gutted, and that one can therefore prevent this migration by freezing or thoroughly gutting the fish immediately after the catch. But “upon information and belief”, this is completely wrong.

        The worms migrate into the fish’s flesh as soon as they can. They start as eggs laid inside the gut of marine mammals; they are excreted with the mammal’s waste, and float in the sea until they are swallowed by shellfish, that are in turn eaten by fish. In the fish’s gut the eggs hatch, and the larvae immediately burrow into the flesh, curl up in cysts, and go to sleep until the fish is swallowed by a mammal. If that happens to be a marine mammal (whale, dolphin, etc.) then the larvae mature in its gut, mate, lay eggs, and die. If it’s a human, they try to do the same, but fail and die, because our guts are laid out differently than those of dolphins.

        The po’el yotzei is that by the time the fish is caught the worms are already embedded in the flesh. Freezing or thorough gutting will not help.

    11. The fact that the worms are digested from outside of the fish is meaningless in light of the Gemara in Chullin that says that the worms ‘originate in the flesh’. This is the same as the Gemara in Shabbos that lice are not “porim v’ruvim’, that they do not come from eggs, but rather spontaneous generation. If it appears to the eyes of an iron age person of the days of the Gemara that these worms originate from within the fish, then they’re muttar.
      The Torah was NOT given to people in the age of science, the Torah was given in a generation of the midbar! These worms are MUTTAR, they have always existed within fish, through the past 3,500 years of Jews eating fish. They’re muttar whether or not they were “spontaneously generated” in the flesh of the fish, even if we can prove with microscopes that they did not, it does not matter! This is no different than the lice on shabbos. We can now prove that lice come from eggs, but since a person in the days of Chazal would not have come to that conclusion, and thought they were bourne of sweat and dirt, then the lice are muttar to kill on shabbos. The halacha was nichsam 1,500 years ago and you cannot change that.

      • Yasher Koach. It seems counter intuitive to consider all of these fish treif since it treifs the fish retroactively for all generations until Mattan Torah. There is no way (beyond an assumption) to say that all housewives in all kehillos in all generations cleaned or didn’t clean the insides of the fish completely and correctly and therefore Lo Roeenu Aino Rayoh. Once again, an example of the fall of the fifth shulchan oruch concurrent with the rise of “OCD Judaism”.

        Az men fregt iz treif, iz ver bet dir fregen? If we only examined our ahavas yisroel or our shmiras haloshon under electron microscopes and light boxes, maybe we would rid ourselves of the really insidious worms that are eating our neshomos.

      • If you hold that this is a problem, then you can’t eat wild salmon, but you can eat farmed salmon. Lox is not usually a problem even if it comes from wild salmon (which it usually doesn’t), because it’s sliced so thin that you could easily see the worms if they were there.

      • #27 – I was asking the same question. He doesn’t say anything about the Wild Alaska salmon, which has been difficult to get (most are farmed). You can get the Wild Alaskan Salmon in the cans. Hopefully, they are OK, as they are one of the healthiest fish. Just another addition to the difficulties of these crazy times.

    12. Re: The anisakis while being in the gut is ussor according to all opinions, yet when it goes into the flesh (through the guts) it sudenly becomes mutter? impossible-it retains the status of “isser”.
      It usually found near the belly flap, because that’s where it came from.
      Chazal are addressing a different type of worm. An insect attaches itself to the fish (skin), punctures the skin and lays an egg in the flesh under the skin. That worm has grown from an egg injected in the fish & it’s found near the skin not near the gut.

      • That’s what you say. But this anisakis was almost certainly found in fish in Chazal’s day too, and in the rishonim’s day and in the mechaber’s day. It’s unlikely to have evolved since then. And yet they don’t warn us against it. They don’t say that these worms that are found encysted in the flesh are different from a different type of worm also encysted in the flesh. It therefore seems to follow that they meant these worms to be kosher too. Why is another question, but it’s hard to say that they didn’t permit these worms, and merely forgot to tell us about it.

    13. My earlier comment, while flippant, was intented to convey a simple concept. I trust implicitly the rabbonim that give the hechsheirim on the foods I eat. I think they deserve that trust (until they abuse that trust in any way). An analysis of this sort is wonderfully erudite. But it will not, in my opinion change “the facts on the ground.” Unless I’m wrong, no one is reading this, and then running home to throw out all their Chof-K halibut filets in their house.

      • But not all the rabbonim who give hechsherim agree that it’s permitted. The OU’s poskim allow it, but as you can see in the article many equally prominent poskim forbid it. So flippancy is completely inappropriate. This is a serious shayla, and if the truth is like those who forbid, then you are eating treif no matter how many rabbis mistakenly permit it. That said, it seems to me that the arguments of the matirim are more convincing.

    14. the real reason its become a problem is due to the rampant over fishing chasing the fish from their natural enviroments into warmer climates. everyone in the fish business has known this for years. now go find a rabbi who says doing harm to the enviroment may not just be bad for our health, but for all the neshamas that are eating worms.

        • No your wrong when fish live in warmer waters than they should they become easier targets. Just because these worms existed since creation doesn’t mean they were as much of a problem then.

          • I’m sorry, but this is a matter of basic science.
            Anisakis has been around forever and the only way they can reproduce is by going through the life cycle of being swallowed by one fish to the next.
            Salmon have always had them.
            The only thing that might have changed is that are more of them in every salmon, not that they were never before inside of salmon and every other crustaceon-eating fish.

    15. What Rabbi Hoffman is saying is that his findings do not contradict the gemara. The Gemara is talking in cases where the flesh worms are in a properly gutted fish. Rabbi Hoffman is talking about today’s mass gutting procedures, which leave enough entrail for the worm to migrate into the flesh.

    16. The use of sophisticated scientific equipment for the purpose of prohibiting a commonly eaten food is ridiculous. I’ll also bet that hundreds of rabbonim and tzaddikim ate these worms and their neshamas were unaffected. So lay off the neurotic chumrah search and let people live.

    17. this is getting a little meshigeh. our world is filled with tiny bugs & the like. chazal didn’t seem to mind. but now every little rebbele has a microscope & a light box. pretty soon they’re going to asser everything except water. oh, oops, I forgot, they already assered water in NY.

    18. i will leave it to scholarly rabbis to investigate and issue their halachic opinions.( i also understand there will most likely be a spectrum of opinions from forbidden to allowed)
      on the other hand my question is their a health issue to consuming these fish with worms even if they are allowed from the torah, rabbis and the certifying agencies/rabbis?

    19. This is a frightening situation. It seems that the whole food chain is becoming contaminated in one way or another. The article does not state whether Alaskan Salmon is OK – was always noted to be one of the best. The bad thing with farmed Salmon is that it was reported a number of years ago that there is PCB contamination there. You can’t win. This whole world is one big pollution – this is called ‘progress’.

      • The salmon’s having parasites does not make it “contaminated.”
        Parasites have been around since ma’seh Bereishis, no less than any other creature.
        They are an integral part of the natural cycle, perhaps the most fascinating creatures around.

      • Don’t worry about PCBs, there’s no evidence that they’re harmful. There’s never been any evidence of harm from PCBs save perhaps transient eye and skin irritation, merely a precautionary alarm to which virtually everybody overreacted.

        • So many studies is so many countries all point to the same conclusion. Wild salmon is much healthier than farmed salmon.

          A just-released study commissioned by the Pew Foundation measured levels of organic contaminants in 700 fish (about two metric tons), purchased from wholesalers and retailers in large cities in North America and Europe. Whole, raw, farmed salmon, farmed salmon fillets, and whole wild fish (representing five species of Pacific salmon) were tested. Fourteen chemicals were studied, including toxins such as PCBs, dioxins, dieldrin and toxaphene – all fat-soluble compounds that tend to accumulate in the fat of ocean fish.
          interactions into account when developing recommendations, to help safeguard against adverse effects.
          The general findings are shocking: the expert commission found that the total organic contaminants were consistently and significantly more concentrated in the farmed salmon as a group than in wild salmon. This includes dioxins and PCBs – both believed to increase the risk of certain cancers and to be harmful to the developing brains of fetuses and infants of women who are pregnant or breastfeeding.

          • Yeah, yeah, commissioned by the Pew Foundation. That tells me all I need to know. When have they ever paid for a study that *didn’t* play into their extreme leftist agenda? They have the chutzpah to dismiss any study funded by industry, but we’re supposed to take the studies they fund as gospel, you should pardon the expression?

            In any case, read what you just wrote. What did this study find? That farmed salmon has more PCBs and dioxins than wild. OK, who’s disputing that? But what evidence is there that they’re harmful? The answer is *none at all*. Your study says they’re “believed” to cause all these things; believed by whom? Only by gullible fools, who’ve fallen for the extreme left’s anti-industrial propaganda.



      • Rabbi Reisman in Far Rockaway is NOT “clearly respected in the Five Towns” as you claim (#68). He is in Far Rockaway (and not the Five Towns), and specializes in divisiveness where there is otherwise unity. He maintains a “LIST” of places that are and are not okay, even though the community Vaad and every other Rav in the neighborhood gives their hechsher to those places. If you ask them, the owners of all food establishments in the neighborhood will tell you that Rabbi Reisman tries to extort extra money from them, in order to put them on his okay “LIST”. If they do not pay up what he asks for, he puts them on his “Assur LIST”. So much for a respected rav who cares about halacha. Seems he cares more about his bank account!! The stores want to stay in business and have to choose between having to pay extra to get his followers to eat their food, or not paying him, and having their names go on his bad list. None of it has to do with halacha. It’s purely extortion, in a neighborhood that has a Vaad which all other rabbonim in the neighborhood trust and stand behind!!

    21. To Shaul from Monsey : I would greatly appreciate if you would change you posting name. My name is also Shaul and I live in Monsey and I am constantly getting harassed about comments you post as people think I am you

      • You’ll have to live with the accolades. Monsey is a big place, maybe you can go with Shaul in Forshay or Shaul in South Monsey.

        In all seriousness, very funny to hear you say that. The truth is most of the time I post just to stir the cholent, I am far less opinionated in matters of real life concern. And less obnoxious, caustic and vituperative.

    22. Once the biggest gedolim in eretz yisroel gave their opinion (rav Eliashiv shlita and rav Wosner shlita and Rav Korelitz whois GREATER then them b”chochma u’beminyan to argue. When dealing in an issur deoraysu with 5 lavin how can you enter in such a shailah.

        • first of all did they really say anything?

          why can’t someone finally just write a tshuva on this. this is not a new problem its been around for years

      • Rav Eliashiv, Rav Wosner and Rav Karelitz would all strongly protest the notion that other Poskim are not allowed to disagree with them, and that people are not allowed to follow their own Poskim. Like any area of halachah, you follow your own Posek; it does not matter what “the biggest Gedolim” say. Rav Moshe Feinstein writes this explicitly in Igros Moshe.

    23. #84 – it”s been known for years that farmed fish are full of PCB’s and other chemicals, and pollutants, etc. For years, also, it was a fact that Wild Salmon was the healthiest, but apparently, with everything changing so fast, too much fishing, etc., the food chain, including the fish, have become polluted. This has nothing to do with the leftist environmental propaganda, just the insanity of the times.


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