How to cook frozen fish

Most fish that we consume, even fresh fish, have been frozen at some point. If you live close to the sea and you’re picking up your fish from the fish market first thing in the morning, then maybe you are the exception, but the reality is the fish we eat was either frozen out at sea or at some point along the supply chain, before being thawed and presented at the fish counter. So, you can see why frozen fish has become more popular with consumers in recent years.

Just because a fish is found in the frozen foods compartment in your supermarket doesn’t necessarily mean that the fish is inferior to ‘fresh’ fish at the fish counter. In fact, often the fish is frozen at sea, immediately after it is caught and processed, meaning once thawed, you may have a fresher product than the one that is bought at the counter and then sits in your fridge for a couple of days.

How to thaw frozen fish

The best way to thaw frozen fish is to leave it in an airtight container in your fridge overnight, but that is not always an option. Avoid leaving fish on the kitchen counter to thaw, as, while it might be quicker, it could expose the fish to bacteria that could make you sick. Instead, put the fish in an airtight Ziploc bag and place it in a bowl of warm water. If the fish floats, use something like another bowl to weigh it down and submerge it. Check from time to time to see how the fish is thawing. Change the cold water to new hot water if necessary. When the fish is flexible, but still has a little rigidity in it, it is ready to cook.

The milk hack

This is absolutely the best way to thaw and cook frozen fish. Marinade your fish in milk as the protein and the enzymes will not only allow for the fish to thaw quicker, but will also break down the fish meat, making it more tender, without affecting the texture of the fish. This is also great for tougher fish like octopus or squid, leaving them to soak in milk in the refrigerator for eight hours or so ensures the thawed fish will cook surprisingly well. Add herbs, salt and pepper to the milk marinade to impart flavour. Frozen fish will not marinade and absorb a lot of extra flavour, but it will take some.

Can I thaw fish in the microwave?

It might be tempting to nuke the frozen fish in the microwave to save time, but resist the temptation if possible. The microwave is useful for thawing all kinds of things, but fish is not one of them. The microwave will cook thinner parts of the fish while leaving other parts raw and will give your fish a rubbery texture once cooked. Fish is all about the right texture and you should cook your fish from a thawed state, evenly and carefully, paying attention to the texture and surface temperature.

How to cook frozen fish

You don’t have to fully thaw all fish that you want to cook, it will depend on the type of fish that is frozen as well as the size of the piece of fish. If you need to you can cook fish like cod or salmon directly in the oven, in the roasting pan, or by baking, poaching or steaming. Avoid pan-frying frozen fish as it will release a lot of water when cooking and will turn to slush.

If you are cooking fish straight from the freezer, make sure to rinse it under the tap, and then pat until thoroughly dry. This will remove the thin layer of ice crystals from the outside of the fish which will allow the surface to brown once exposed to the heat.

Because a frozen piece of fish contains more water than a fresh piece, when you cook it from frozen, that water escapes through the skin. It means the skin becomes soft and soggy. You will not get a nicely cooked piece of fish with a lovely crispy brown skin when cooking straight from frozen. So, if you can remove it before cooking, or even after cooking, do so.

Can I cook frozen fish in the air-fryer?

If the fish is cut into small pieces you can cook the frozen fish directly in the air-fryer. You will need to preheat the air-fryer for four minutes at 190°C/380°F, then place the frozen fish pieces in the frying tray spaced out, close it and then fry for 12-13 minutes, until golden brown.