Updated August 19, 2022
STAR-K receives many questions about purchasing fresh fish from non-kosher stores or sources. We hope this brief article will help clarify some of the confusion regarding this topic.
For a fish to be kosher, the Halacha is that it needs to have fins and scales. Furthermore, there is a rabbinic prohibition to consume fish that has had the simanei kashrus (scales) removed (e.g., a skinless fish fillet) without a Yehudi having confirmed that it was a kosher fish.
Stores with Kosher Supervision
In stores or companies that are under STAR-K supervision, the fish are filleted with a mashgiach present, and therefore one may buy any fish fillet without any further concerns.
Skinless Fillet from a Non-Kosher Store or Source
Purchasing skinless fish either from a store that is not kosher supervised, or that was not sealed in a package bearing a reliable kosher symbol, is not permissible. STAR-K does not consider the color of a fish alone (e.g., the red color of salmon) to be a valid siman kashrus.
Buying a Whole or Cut Fish from a Non-Kosher Fish Store or Counter
Technically, one may go to a non-kosher fish store, ask for a whole fish with skin/scales intact, ensure that the knives and cutting boards are fully clean, and have them fillet the fish for you while you observe. However, this is not always feasible, particularly if the store is busy or the cutting area is not easily visible.
Furthermore, the equipment really does need to be checked to be 100% completely clean, which may not be so feasible either.
STAR-K does not recommend consumers purchase fish from a non-kosher store in this manner unless there is no other option. A Rav should be consulted to determine if your situation warrants allowing this. Alternatively, one may buy a whole fish and cut it at home, which would avoid all the above issues.
Buying Commercially Packaged Fish with Skin/Scales Still Attached
Fish that has the skin/scales intact and is sold packaged from a commercial fish company (NOT cut up in the store) may be purchased and used without any concern of non-kosher fish residue. The reason for this is that commercial fish processors typically produce fish in large quantities on dedicated equipment, and therefore there is very little concern of residue.
other relevant issue is that some wild-caught fish are potentially infested
with anisakis worms and should be avoided. A common example of problematic fish
is wild salmon. A complete list can be found here.
For more information, contact the STAR-K Kashrus Hotline at 410-484-4110 Monday through Thursday 9-5, Friday 9-2, or email us at [email protected]
 See Avoda Zara 39aand TShu”a 118:1.
 When the skin is attached, even if the fish has already been descaled, the outline of the scales is usually visible. That is enough to confirm the fish as being kosher.
 Consumers should not negate the possibility and concern of cross-contamination from non-kosher fish on shared equipment, as our mashgichim who work in the fish industry report this to be a common practice, and thus, a real concern.