Improper thawing can compromise the quality of any frozen seafood, no matter how it is frozen or packaged. Thawing methods can also affect the net weight of the product. 

Frozen fish can be defrosted in air or water or by cooking directly from the frozen state. The best results are obtained when a product is thawed slowly (for 36 hours) at temperatures just above freezing. A complete thaw, especially under forced conditions of warm air or water, may release “natural juices” that represent a portion of the product’s net weight and flavor. Always place thawing product in a drip pan to avoid build-up of melt water and drippings. 

Thawing too long or at too warm a temperature may dry out the product and invite bacterial growth. Because of the superior heat-transfer properties of water, it is a faster thawing agent than air. The cold water should be kept moving (spraying works well) while gently agitating the product. 

Whole or packaged fish may be thawed in water, but unpackaged fillets should not be defrosted in this manner because they become waterlogged and lose flavor through leaching.