The Reason Run-Of-The-Mill Tinned Fish Tastes Fishy

There are few foods that have had a greater glow-up than tinned fish. One reason for tinned fish's newly fashionable reputation is the increase in high-quality tinned fish companies. Well-made and well-sourced canned fish has been available in places like Spain and Portugal forever, called conservas, and American competitors like the cult favorite Fishwife have been stepping up the availability of domestic quality tinned fish.

This is crucial because there is a huge difference between premium tinned fish and the 99-cent cans of tuna you can buy in bulk at the grocery store. Some cheap tinned fish may have a distinctive fishy taste that distinguishes it from fresh fish. The reason doesn't just have to do with the quality of the fish itself but with how it is processed and cooked. According to chef and TV personality Andrew Zimmern, "Tinned fish that tastes fishy is from fish that is cooked before being tinned" (via YouTube). This results in fish that is overcooked, which releases all of its juices and oils, creating a strong taste and smell.

The fishy taste is due to the oils being released when the fish is cooked

Zimmern goes on to say that the best tinned fish is when it is tinned first and then cooked under pressure, which is known as the raw pack method. In order to make the tinned fish shelf stable, it must be cooked at high heat and hermetically sealed to prevent spoiling.

Pre-cooking is more common with large fish like tuna, which would explain why canned tuna has such a famously stinky funk to it, while smaller fish like sardines do not. Another thing to consider is that tinned fish usually comes packed in either water or oil, and oil-packed tinned fish generally has a stronger, slightly fishier flavor. 

However, if you do wind up with an extra fishy can of sardines or mackerel, there are solutions when it comes to preparing and cooking it. You can balance out the brininess with acid, like citrus or tomatoes, which will make the flavor less aggressive.