5 Tips for Buying Frozen Fish

June 22, 2016

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:

1. Look to eco-labels

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.”

2. Peek at the geographical data

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.

Shop the Story

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.”

3. Know your acronyms

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.

4. Thaw it safely

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.

5. Or cook it right from the freezer!

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.

See what other Food52 readers are saying.

  • food king
    food king
  • AntoniaJames
  • cheese1227
I am an excellent eater (I have been all my life). I’m a pretty good cook (Ask my kids!). And my passable writing improves with alcohol (whether it's the writer or the reader that needs to drink varies by sentence.). I just published my first cookbook, Green Plate Special, which focuses on delicious recipes that help every day cooks eat more sustainably.


food K. June 7, 2017
Some times its good that you know how the fish will mature, even though they are fresh, some fishes will taste more delicious after they are caught days after, fishes may have chemical reactions that improves it richessness overtime! I learn them about it in this blog
AntoniaJames June 22, 2016
So helpful, Christine! I appreciate the tip on cooking cod from frozen. Unless I'm in a place where the local fish has been brought in on a boat within a few miles that morning, I almost invariably buy frozen; cod has become a real workhorse in my kitchen. I love the convenience and flexibility of good frozen fish, so I'm glad to see this piece spreading the word. Thank you! ;o)
cheese1227 June 22, 2016
Excellent AntoniaJames! So glad you found it useful!