The rules surrounding the eating of fish in Jewish law is particularly difficult, as whether fish are kosher or not will depend upon the specific regulations set out in the laws... 

Is it possible to find kosher tuna?

The rules surrounding the eating of fish in Jewish law is particularly difficult, as whether fish are kosher or not will depend upon the specific regulations set out in the laws. For example, only fish which have scales and fins may be regarded as kosher, and therefore can be eaten. If you buy fresh fish, it must be easily recognized as kosher, and this means that you cannot buy fillets, for example, since you would not be able to recognize the fish or the species. The only way that this does not count is if it is supervised by a Rabbi, or the Jewish customer sees the fish being filleted. There is also the added difficulty in a fishmonger of ensuring that the tools used are kept completely for the kosher fish, or are thoroughly cleaned before the filleting starts.

 The status of tuna

There is a lot of dissent about tuna, as although it does have scales in the water, these will shed, along with mackerel and herring. In other cases, the tuna being caught is too young to have developed the necessary scales. In this case, you may find suitable tuna by looking under the gills and fins to see at least one scale. If there are no scales, then the only way to certify the fish is to have it viewed by a rabbi or expert who is known to be God fearing. This makes the status of tuna very difficult unless it has been certified.

 Finding kosher tuna

Unless you intend to buy all of your tuna from a local fishmonger, then you will need to find tinned kosher tuna which is suitable for you to eat. The majority of standard tinned tuna will not be kosher, since it is not prepared in a supervised manner, and many Halachic leaders consider that finely cut tinned fish, without the skin, is not permitted, so you will need to find tins that have been prepared in a suitable way, and which fall under the rules approved by your local Jewish leaders. This can be done by finding a seller who has certified tins of tuna. These are products which are guaranteed to be kosher, since the food has been checked and verified by a professional. There are a large range of tinned tuna products which have been prepared according to tuna regulations.

Sellers of tinned tuna which has been prepared in a kosher way can be found online, where they are likely to be able to offer you a selection of different tins. Search for ones with OU, OK, KA or KU on them, as these are the most suitable types of tinned tuna.