One of the biggest problems I hear from the people when it comes to grilling fish is sticking. Strange thing is that people claim they are cooking on a completely clean surface that has been oiled, or fish marinated in an oil based marinade. So why does it stick? What's going on here? Technically food sticks because as it breaks down it creates many sticky substances. If you leave this behind on your cooking grates the next thing you cook will stick. But why does the fish stick to a clean cooking surface if it hasn't been cooked long enough to create these sticky things?
Answer is that the fish isn't sticking, its seizing. Like a warm tongue sticks to the frozen flag pole cold, or cool meat with fuse to hot metal. The secret is to keep the temperature down on your grill (limit your preheat times) and then be patient with the cooking. If you notice that the food you are cooking has fused to your grill, let it go a little longer. If you try to scrap the fish off the grate you will pull it apart, but chances are you will be able to lift it off before it burns if you watch it closely. So next time you have something stuck to a clean grill leave the lid up, turn down the heat and wait for the fish to let go of the metal.
Photo © 2007 Derrick Riches, licensed to About.com, Inc.