Published May 1, 2012. From Cook's Illustrated.
If you hate the unsightly white film that forms at the top of cooked fish, you aren't alone. Here's how to minimize it.
We often advocate brining meat (and sometimes fish and shellfish) before cooking to ensure moist, tender, flavorful results. We recently discovered a whole different reason to soak fish in a salt solution: A quick exposure can reduce the unsightly white layer of albumin that coagulates on the surface during cooking. Just 10 minutes in our standard 9 percent solution (1 tablespoon of salt per cup of water) is enough to minimize the effect. The method works in a similar fashion to how a longer soak improves moisture retention. The salt partially dissolves the muscle fibers near the surface of the flesh, so that when cooked they congeal without contracting and squeezing out albumin. We tested the method on white fish (including cod and haddock) as well as on fattier salmon and saw a dramatic improvement in both. The brief soak also seasoned the fish’s exterior, making it unnecessary to salt it before cooking.
UNBRINED, THEN COOKED
Marred by patches of white albumin.
BRINED, THEN COOKED