The Prep Step You Shouldn't Skip When Grilling Fish

Grilling fish might seem intimidating, starting with choosing what kind works best when cooking one whole, picking the freshest kind at the grocery store, and then when you get it home, avoiding these common, but fixable, mistakes – like overgrilling. But it can actually be pretty straightforward, with minimal prep. Food Republic spoke to Costas Spiliadis, founder of Estiatorio Milos, to learn more. He had some specific tips, especially for cooking an entire fish: "Season your fish prior [to] grilling it." Doing so will help prevent your delicate fish from sticking to the grill grates. Plus, the salt, pepper, spices, or rubs work their way in through the scores and flavor the inside of the fish, not just the outside.

He also suggested, "If the fish is whole, score it on the sides to help it to cook evenly and avoid being too dry on the outside." Fish cooks fast, so it's easy for it to dry out if you're not careful.

To score a whole fish, you'll want to use a very sharp knife, so you're not hacking and sawing into the skin. Hold it so that the blade penetrates the skin at a 45-degree angle, and starting under the pectoral fin (that's the fin that sits just below the gills near the head), make your first incision. Now, you can decide both how deep you want to cut, and how far apart you want to make the scores.

For example, you can cut to the bone, but some prefer not to; experiment to see what you like. A good rule of thumb for the distance between scores is about an inch and a half, but again — your fish, your rules. When you're done with one side, flip over the fish and repeat the process on the other side. 

You should absolutely still score your skin-on fish filets before grilling, too, for the same reasons listed above for whole fish (and if you were to pan fry or sear your filet, it would help the skin crisp up, so keep this technique in mind for indoor cooking). However, it's going to be a little different from scoring whole fish, and you won't want to cut quite as deeply. Instead, using a very sharp knife, you'll make three evenly spaced shallow cuts, through the skin and just through the top of the flesh, about an inch and a half long, on the vertical (or across the length) of your fish. 

In addition to scoring your fish fillet's skin for even cooking, you can give it an assist with the grill technique you employ. According to Costas Spiliadis, "If you are cooking a [filet], let it cook mostly on the side of the skin, which is usually more fatty, and just a touch on the flesh side to fully cook and give color." This way, you won't dry out your meat but will still get some color (maybe some nice caramelization) on both sides — with crispy skin to boot.