Not all fish are created equal when it comes to cooking. Cold water fish often tend to be oilier than some leaner fish from warmer waters. Some fish have firm flesh while others have really delicate and flaky flesh.
Depending on the species, fish can be sautéed, steamed, fried, baked, broiled, grilled, poached, and even smoked. No matter which method of cooking you use, there are a few tips for knowing when the fish is cooked properly. A good rule of thumb to start with is to cook fish approximately 10 minutes per inch of thickness until just done. Overcooking fish does not produce appetizing results.
Keep an Eye on the Flesh
Your eyes are the greatest tools for determining when fish is cooked to perfection. Most fish are slightly translucent when raw. As it begins to cook, you will notice that the side closest to the heat source will begin to become opaque. When that happens, turn the fish over. Once the center of the flesh just begins to turn opaque, the fish is likely cooked through enough to remove from the heat.
Remove it to a clean board or serving platter and allow it to rest a few minutes. It will continue to cook.
Touch the Fish
Your fingers are the next best tools for figuring out when the fish is ready. The flesh will firm up as it cooks. When you press lightly on the fish there should be a slight resistance to the touch, indicating that the flesh is firm. If the fish feels very soft and doesn’t spring back, it is likely still raw in the center.
Check the Temperature
An instant read digital thermometer can be one of the best methods for determining when proteins are cooked sufficiently. With fish, you are looking for an internal temperature of 145°F or 63°C.
Flake the Flesh
Watch the fish as it cooks to see if the muscle fibers start to separate. This indicates that the meat is becoming tender. Don’t be shy to take the tines of a fork and check to see that the fish actually flakes or pulls apart easily. The flesh should still look moist. If it flakes too easily it might be dried out.
Remove the Bones and Skin
If you are cooking a fresh fish that still has either the backbone or skin intact, you should be able to separate the skin from the meat easily. The backbone should be able to be pulled out in one piece as it is no longer attached to the flesh. You can always serve the fish with both the skin and bones left as they are. Just be sure to check a small section for doneness first.
Fish cooks quickly. It is best to prepare the rest of your meal before cooking the protein. Be sure to remain attentive when cooking seafood. The results will be worth the thoughtfulness you put into preparing your fish.