The Real Reason Your Frozen Fish Is Mushy

Updated on 6/10/24 to specify that botulism can affect vacuum-sealed frozen fish that's thawed in a refrigerator, so the package should be opened first before using this method.

Being able to buy frozen fish, much like chicken, is one of the best ways to ensure you are buying tasty fish, especially because it is frozen quickly after it's first caught, according to The Spruce Eats. Of course, sliced-and-ready-to-go fish at your regular grocer is a solid choice, but having some in your freezer for a rainy day is an added bonus.

The vacuum-sealed and perfectly-sized portions of fish, ready for cooking, only add to the convenience. The flash-frozen fish is good for any dinner meal you may be planning. There are some tricks to keep in mind when it comes to a bag of frozen fish, though, to help make sure your meal is up to par (or even better).

When it comes to defrosting fish, you can end up with a mushy mess if it's not done the right way. If you are one of those people who tend to put their frozen fish in water, unsealed, for a quick thaw, you may want to switch up your routine.

Believe it or not, there is a bit of solid science that explains why mushy fish is the end result of a fast thaw. Cheat Sheet explains that the cells in fish contain liquid, and when that liquid freezes it creates ice crystals. Once these ice crystals are thawed, the liquid pours out into the fish, resulting in the mushy mess (via The Spruce Eats).

This isn't the only reason your fish may not be the winner at dinner. Fish, just like other meats, is a protein, and protein that sits in acid liquids too long — for instance, marinades — can cause the fish to, well, fall apart and turn mushy, reports The Today Show. If you want to marinate your fish, be sure to only do so for about 30 minutes.

If you are now worried you've been defrosting fish all wrong, look no further. The best way to defrost your frozen and vacuumed-sealed fish is in the refrigerator overnight (via The Spruce Eats). If you happen to remember the night before, dash to the freezer and switch out your tilapia or salmon for a warmer fridge temp. However, it's important to note that fish is at risk for botulism when thawed in the absence of air, so you'll actually want to break the vacuum's seal before doing this.

If you are short on time, not a worry: You can pop your fish into a bowl of cold water for a quicker dinner prep. But be sure your fish is sealed shut and the water is chilled or you'll be the real reason your fish is mushy.