Freezing Store-Bought Seafood Is More Harmful Than You May Think. Here's Why

Fresh fish straight from the ocean is best, but is it ok to freeze fish if you can't eat it right away? We asked Maricel Gentile, owner of Maricel's Kitchen, for advice. Gentile says freezing fish is ok, but the process could mess with the taste and texture. It's when you re-freeze fish that things start to get, well, fishy. 

"The real issue with refreezing seafood is quality," Gentile says. "If seafood was already previously frozen, refreezing can harm its texture and flavor." The ice crystals that form when fish is frozen break down the cell walls. "It becomes mushy because of water crystals breaking down the flesh," she explains. Re-freezing makes the problem worse.

But that's assuming you even thawed the fish properly. The safest method for thawing food involves leaving it in the fridge overnight. If you forget to take the fish out of the freezer the night before, you can seal it in plastic and place it in a cold water bath. Whatever you do, don't leave the fish to thaw on the counter. Leaving food at room temperature puts it at risk of developing bacteria.

While thawing any type of food at room temperature poses a safety risk, you need to be especially careful when thawing fish. Most fish evolved to live in chilly lakes, rivers, and oceans, so their bodies decay quickly at room temperature. Since farm animals like pigs, cows, and chickens have to handle upwards of 90 degrees Fahrenheit or more, their meat is more heat-tolerant. Don't assume that a fish fillet can handle the same treatment as pork chops.

"If fish is thawed properly in the refrigerator, it can be safely refrozen, though the texture may suffer a little," Gentile explains. "What you want to avoid is refreezing fish that has thawed at room temperature, because bacteria may have multiplied." By the time the fish reaches room temperature, it's already too late. "If seafood sits out on the counter until it is fully defrosted and warms up, bacteria begins to grow," she says.

Gentile emphasizes that refreezing fish that's already spoiled won't make it safe to eat again. "At that point the fish will often smell or taste off, and refreezing will not rehabilitate it," she says. "Once it has gone bad, it stays bad." That's why the Food and Drug Administration recommends avoiding packages of pre-frozen fish harboring ice crystals inside. Crystals could be a sign the fish has thawed and been refrozen during transportation. 

According to the USDA, fish should be stored at 40 degrees Fahrenheit or less (the fridge makes the cut). To keep fish fresh in the fridge for as long as possible, do as chefs do and store the fish on a bed of ice. Make sure to eat it quickly, though. Fresh fish should only be kept in the fridge for a day or two.

If you have to freeze your fish, make sure to do it right. Always clean the fish and give it a rinse under running water before freezing it. "Wrap it tightly, keep it at a steady temperature, and use it within a few weeks," Gentile advises. Remember that some fish will freeze better than others. If you're choosing between two types to freeze, pick the leaner fish. Lean fish have less moisture, so fewer ice crystals will form.

You can also try ice glazing, which involves coating the fish in a thin layer of ice to seal in moisture. To ice glaze fish, put it in the freezer until it's just barely frozen, dunk it in ice-cold water, then freeze it again. Repeat the process a few times until the fish is covered in a solid glaze of ice, then pack it up for long-term storage in the freezer. The USDA advises eating frozen fish within three months.