We picked up some halibut for Pesach directly from the packer. This fish has not had the skin removed. The box clearly was sealed with the O-K. But my wife was uncomfortable that we could not find the scales on the skins and identify that this is in fact a Kosher fish. Since the Mashgiach is Yotzei v'Nichnas and not Timidi, we would like to verify the skin itself has scales. Has anyone seen them? How can we be satisfied that this fish is in fact Kosher under the circumstances?


3 Answers 3


Regarding the actual question:

HOW TO CHECK A FISH TO DETERMINE KOSHER STATUS: see the article posted on crc website: http://www.crcweb.org/kosher_articles/kosher_fish.php By: Rabbi Chaim Goldberg - OU Rabbinic Coordinator: Fish Industry Printed with permission of the OU and originally appeared in "Daf HaKashrus". It answers succintly how to check for scales.

I would like to point out something seemingly obvious to me based on the info Dr. YSG initially posted, which makes irrelevant all the nice, scholarly responses, complete with sources, to this post.

First of all: "The box clearly was sealed with the O-K." Great. They are experts in fish production AND all the relevant Halachic sources AND clearly have excellent systems in place to ensure ONLY kosher fish is being processed and then packed with their seal.

[Disclaimer: I am aware that this post is predicated on MY ASSUMPTION/ UNDERSTANDING of Dr. YSG's choice of words when posting his query. I may be guilty of misunderstanding his words. Hence, this may be entirely irrelevant. If so, I apologize.]

---->>>> PERHAPS the reason why Dr. YSG couldn't find scales may very well be because the fish, after having been checked for kaskeses (scales) by a knowledgable, torah observant expert; drumroll please... was SCALED! "We picked up some halibut for Pesach directly from the packer." Dr. YSG never said the fish, coming from the packer, came in before it was gutted, cleaned and turned into a nice piece of fillet (with the skin on.) (Did they buy it whole with the head, tail and and the pieces attached to the fins still intact? I doubt it. The spine was probably discarded, bones picked out etc.)

One can assume that the mashgiach made sure to check the large cases of boxes storing the dozens of fish before he gave his approval to allow these fish to be cleaned, packed and sealed. (I've done work at a fish wholesale place and am aware of the way -- in certain places -- the fish is processed, and the general setup /layout of a medium scale fish production place.)

In other words: just because the skin is on, doesn't mean the scales are STILL attached. Many pieces of salmon are sold with their skin on (for looks or taste; to keep the flavor locked in when seared/ grilled etc.) but the skins are smooth and clean = appetizing. They don't have the silver and black shiny (reflective) look that the scales give the fish when completely intact. (Compare this to poultry: you often buy chicken with its skin on, but, thank Heavens, it has been plucked of its feathers (hopefully) and washed/ scrubbed down.)

So buying fish "directly fom the packer," as Dr. YSG originally posted, doesn't translate to having unprocessed, scales-attached-to-the-skin fish pieces/ fillets. Fish can be "minimally processed" or "heavily processed" from a packer/ distributor/ fisherman, and then left (the cleaned, large slabs/ fillets) to be further processed and/or divided according to the retailors' individual prefrences..

[To reiterate: All fillet fish can be sold from the distributor, "packer," wholesaler, fish producer AFTER they've been cleaned. Prepping/ cleaning MAY include: gutting; SCALING; cleaning/scrubbing; and de-boning the fish for later cutting down to size. That big cleaned up slab/piece (which can weigh a quite sizable many pounds) is then sent to a local (retailer) fish shop where the proprietor may further divide it into a specific thickness and width of individual pieces.]

Finally, one last point. "Since the Mashgiach is Yotzei v'Nichnas and not Timidi, we would like to verify the skin itself has scales." -- From what I know about mass fish production, including the layout of the individual warehouse (design can make a huge difference in keeping up reliable tracking of the unprocessed and processed fish), the system of how the fish is processed, the line used for each step of the processing (cleaning) and the system in place between the mashgiach and the fish production owners, I can tell you that if the Mashgiach has checked all the dozens of cases of fish (each day) before it goes to the area of the factory which deals with further processing (including: cutting them open and gutting, cleaning, filleting, de-boning, and cutting to size), then the system in place and the design of the wharehouse (including storage/ holding areas etc.) may well be more than adequate and very reliable. Again, this is why we rely on large, reputable hashgocho agencies who employ yirei shomayim AND have immense PRACTICAL knowledge of the particular industries/ fields they are involved in.

-- The reason I wrote this response (nearly 4 yrs after the original post) is to prevent others from erroneously concluding, as some of the responders may have, that not finding scales on a piece of fish that has its skin attached = fish had no scales to begin with, so is treif. This exchange comes up in google queries to specifically worded kosher fish questions.

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    Welcome to Mi Yodeya, Shea. I hope you enjoy your time here Commented Mar 20, 2018 at 4:26
  • Thank you. Just in time for pesach where we will be buying another case of fish from them. But probably just salmon. Your analysis matched what we saw.
    – Dr.YSG
    Commented Mar 20, 2018 at 9:13

From Wikipedia

Halibut are dark brown on the top side with an off-white underbelly and have very small scales invisible to the naked eye embedded in their skin.

  • See Tif'eres Yisra'el (Avoda Zara, Bo'az 2:3) for a discussion of the kashrus of fish whose scales are not visible to the unaided eye: והתורה אמר לנו רק לסמוך על הדבר הנראה בלי זכוכית... וכן אנו רואין קשקשים קטנים בזכוכית המגדיל, וכי ס"ד להתירו ח"ו משום זה. ע"כ יפה כתבו רבותינו שישתקע הדבר ולא יאמר התירו. (Interestingly, the T"Y discusses this incident ad loc.).
    – Fred
    Commented Apr 29, 2014 at 21:45
  • @Fred, the source of that Wikipedia statement seems to imply that the scales are not microscopic, just buried in the skin.
    – Yishai
    Commented Apr 29, 2014 at 22:11
  • yes, I saw this wikipedia article. But not visible to the naked eye. Does that not raise flags? If I cannot see the scales the question of the Tif'eres Yisroel pops out at me! and further searching leads me to lean to @Yishai view, so back to my question, I have the skin in the frig, can I scrape it and find the scales?
    – Dr.YSG
    Commented Apr 30, 2014 at 19:07
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    @Dr.YSG Aruch HaShulchan (YD 83:15):יש מיני דגים טהורים שקשקשיהם דקים מאד ואינם ניכרים ולכן אם כרכוהו בבגד או נתנו אותו בכלי מלא מים ונמצאו קשקשים מותר... וכן אם העמידו הדג נגד השמש ורואין בו קשקשים קטנים מותר אמנם בראיה בעלמא אינו מועיל לפי מה שנתבאר דצריך שיהא ביכולת לקולפן. The A"H suggests finding hard-to-see scales by examining if you can see scales slough off into water or onto a cloth. He also suggests looking in sunlight but adds that seeing scales on a fish isn't enough if you don't know if the fish is a kosher type, as the scales must be of a type that can be readily scraped off.
    – Fred
    Commented May 1, 2014 at 17:13

from Kashrut.com

There are two ways to identify a kosher fish:

1 - By removing a kosher scale from the skin. 2 - By recognizing the fish as being from a kosher species. One can only recognize a fish species if the skin is still intact. It is generally impossible, even for a “maven”, to identify fish without skin.

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