Frozen fish and shellfish are in many cases a cook’s best option for quality, sustainably sourced, convenient seafood. There is really no fish that can’t be frozen at its peak of freshness after it’s been pulled from the water and properly processed, but it’s important to think about how it was handled from the freezing point to your plate: where it comes from, in what manner it was frozen, and how to prepare it before using it in your favorite recipes.
Here are 5 tips for buying and cooking with frozen fish:
One Fish Foundation Founder Colles Stowell says seafood lovers can look to eco-labels like Friend of the Sea and Marine Stewardship Council as a starting point in their selection process because both organizations “shed light on the network of links between the fishing boat and your plate.”
Stowell says geographical data printed on a package of frozen fish is the real key to knowing whether the fish has been harmlessly pulled from the sea in numbers that don’t jeopardize future stocks. Whenever you can, buy local frozen fish. If that’s not possible, buy American—whether that’s Alaskan, Gulf of Mexico, or Gulf of Maine.
The United States has the strictest, most highly regulated fisheries in the world, explains Monique Coombs, Seafood Program director for the Maine Coast Fishermen’s Association. She maintains that if the frozen fish were caught by American fishermen, under US regulations, then the fish is considered “sustainable.”
To further understand the options in the freezer aisle, it’s important to know the difference between products labeled Frozen at Sea (FAS) and Individually Quick-Frozen (IQF).
FAS products may be caught, filleted, and frozen aboard the same boat. “That’s the ideal situation, because the freshness is locked in until you are ready to eat the fish,” says sustainable seafood chef, advocate, and cookbook author Barton Seaver.
But other times, FAS fish are frozen whole on a factory ship, thawed, and reprocessed at a plant ashore. This kind is sold as “previously frozen” in grocery store cases. This process actually negates the benefits of freezing fish in the first place, contends Seaver, because the longer the fish sits thawed out, the more the quality deteriorates. To maintain the benefits of FAS fish, defrost it as close to when you plan to cook it as possible.
The IQF label is given to pieces of finfish or shellfish that have been fast-frozen as single units, glazed with a skim coat of water that freezes instantly to preserve the freshness of the fish, bagged, and then boxed. The “quick” in IQF simply means the product was frozen in a matter of minutes or hours, not days, using either blast freezing or cryogenic methods that employ liquid nitrogen or carbon dioxide.
When selecting IQF seafood, pull it from the coldest depths of the freezer compartment at the store to help ensure it has remained in its frozen state. Inspect it for signs of freezer burn, ice crystals, and clumping of the pieces of seafood, all of which are signs that it has been thawed and refrozen somewhere along the supply chain.
Regardless of the type of frozen fish you buy, it is best to thaw in the fridge. Many types can be defrosted by dinnertime if you put it in the fridge before work. The fattier fishes (arctic char, salmon, smelts, swordfish or trout) should always be thawed before proceeding with your favorite recipes for fresh fish.
You can easily cook your flakier white fish (cod, flounder, haddock, halibut or hake) from the freezer. To do so, coat frozen fillets with oil and sauté them for 3 to 4 minutes before slathering them with a fatty condiment (I do a 50/50 split of mayonnaise and mustard). Sprinkle them with breadcrumbs or crushed crackers, then finish them in a 425 to 450°F until the fillets are just opaque and starting to flake. On the stove top, it’s futile to try to get a good sear on these frozen fillets due to the fact that they are glazed with water, but they simmer very well in a one-pot seafood stews and chowders.