To effectively freeze uncooked fish without sacrificing any of the meat's quality, focus on removing all air from the container before freezing. The fat content of the fish meat also plays a role in how well the fish freezes and how long the frozen meat will last.
The most effective way to remove air is to use a vacuum sealer to suck the air out of the container before freezing. Another method, called glazing, uses frozen water to shield the fish from freezer burn. To glaze the fish, dip the meat in water, and it place on a pan in the freezer. Once frozen, dip the fish in water again, and repeat the process until there is a 1/4-inch layer of frozen water on the fish meat. Put the fish into a plastic bag, and place it in the freezer.
If the fish only needs to last for a few days, cover the meat with plastic wrap, and place it into a plastic bag before freezing. While not as effective as the previous two methods, this preserves the fish for several days before a noticeable drop in quality.
When employing either of the first two methods, the fish meat keeps up to six months depending on the fat content of the fish. Leaner fish, such as cod or haddock, keep longer than fatty fish such as salmon or trout. Remember to gradually thaw frozen fish in the refrigerator or in a container of cool water. Avoid thawing frozen fish in the microwave or at room temperature.