Storing Fish for Consumption
Proper handling and storage are the keys to keeping your fish as fresh as possible.
The people that read this site are anglers, which means, for the most part, the fish they eat are fish they caught and butchered themselves. Depending on your favorite fish and the seasons in which you can catch them, some people freeze their catch for later consumption. But a lot of people–the vast majority who eat fish–buy the fish they eat. The chefs who prepare fish for the table at your favorite restaurants deal with the same issues. Buying fish of the highest possible quality is only the beginning.
Once you have the fish, whether you caught it or bought it, controlling the temperature of the flesh is the most effective way to slow the bacteria and enzymes that destroy fish and make it unusable.
What Makes Fish Go Bad?
There are several reasons fish go bad. A fish that smells fine can still taste stronger or fishier than it would have had it been properly maintained. And once any fish is past its time, it will begin to smell bad. The time it takes to get the fish from the water to the table, and the temperature it’s kept at during that time, can be the difference between a fresh fish going bad or a fish that’s 12 days old tasting perfectly fine. It all has to do with the handling.
It’s probably not a surprise that the primary reason fish go bad is bacterium. But that’s only half the story. Fish are muscular; the enzymes that enable muscles to contract and relax and assist the process of digesting food turn toxic as soon as the fish dies. In fact, the battle itself can release enzymes that begin to break down the flesh and change the flavor. If you want proof of that, taste fish caught on a hand line, brought up quick and iced fast. The same fish fought on light tackle tastes much stronger than the fish caught quickly. It’s no surprise then that speared fish taste best. It’s a lot like hunting pig. If you injure a pig or even scare it badly before it’s killed, the meat tastes bad.
The third thing that leads to your recently fresh fish going bad is oxygen. That’s right; oxygen. The more oily fish, like Mackerels (including Kingfish and Wahoo), are particularly subject to oxygen’s negative impact on the freshness of your fish. The oxygen and the oil in the meat react, causing the flesh to go rancid.
The longest a fish can be kept without freezing–and it depends largely on the species–is about 15 days. That’s right, 15 days. Of course, a lot of that shelf life has to do with the species and the temperature(s) at which the fish has been kept from the time it was taken out of the water until it’s prepared and served. It’s one of the reasons we tell people not to put fish in melted ice; soaking the fish in water and water that is rapidly changing temperature does not maintain the flesh at its maximum condition. It’s way better to keep the ice in plastic bags and put the fish you catch in between them, and keep them there. The newer coolers–the expensive ones–are designed to keep temperatures even as much as they’re designed to keep stuff cold. It’s the change in temperatures that begin the process whereby the flesh breaks down. Fish does not have to smell bad to not be as good as it could have been.
Quality of Life
Let’s say the shelf life of edible fish begins the moment the fish dies (and the moment the enzymes that supported their muscular systems begin to destroy the flesh). If you caught the fish, you can hopefully put it on a grill, in the oven, or in a sauté pan the same day or the next day. The fish has a quality life of one or two days. Buy fish at the grocery store or fish market, and it has already had a life of three to five days. At least. Remember, the longest they can remain edible without being frozen is 15. And they are way better at no more than five.