Many fish and shellfish benefit from a quick soak in a marinade to boost flavor and help retain moisture. Even so, use care when choosing marinade ingredients and limit the seafood’s time in the marinade so as not to overwhelm its natural flavor. Usually half an hour is enough time to add flavor to a delicate piece of seafood: less time is needed if you are using a strong acid in the marinade, such as lemon juice, which chemically “cooks” the food and alters its texture.
Experiment with different marinade ingredients, and gradually increase the amounts added or the time the seafood is kept in the marinade till you achieve a flavor balance you like. Most marinades consist of varying proportions of oil (flavored or flavorless) an acid (white wine, fruit juice, or vinegar) and spices or herbs.
For Asian-inspired marinades, choose soy sauce, scallions or sesame oil as the primary flavoring agents. Marinades with a Southwestern flair might include the flavors of cilantro and lime. Try flavoring marinades with fresh basil and parsley for an Italian twist. No matter which combinations you choose, season lightly with salt-you may find that you prefer less because the seafood is already deeply flavored (and you can always add more salt once the seafood is cooked).
For easy cleanup, marinate seafood in a food-grade plastic baggie with a re-sealable top. Always marinate under refrigeration and throw out used marinade to help prevent food borne illness. Remove excess marinade from seafood before cooking to help prevent flare-ups when grilling or broiling.