Anatomy of a Marinade

The ingredients in a marinade are limited only by the cook's imagination, but usually adhere to a consistent pattern. A standard marinade includes oil, an acidic ingredient such as wine, fruit juice or vinegar and a variety of other flavoring ingredients such as herbs and spices. The acidic ingredient provides a fresh flavor of its own and acts as a conductor for water-soluble flavor molecules. The oil in the marinade does the same for fat-soluble flavors, often contained in the same spices and herbs. Even a buttermilk marinade -- often used for fried chicken -- meets this description, since it combines milk fat, lactic acid and its own distinctive flavor.

Acid and Protein

The muscle fibers found in animals are relatively long, often extending to several inches. Fish are built differently, with their muscles layered into thin sheets that flake when they're cooked. That's an important distinction, if you plan to use a marinade. The relatively short and delicate muscle fibers of the fish are more susceptible to the acidity in the marinade and begin to contract and become firm just as if they'd been cooked. This process, called denaturing the proteins, causes the fish's texture to deteriorate and become disconcertingly mushy and soft when cooked. A few dishes, such as ceviche, deliberately prepare the fish in an acidic marinade, but don't cook it afterwards.

Marinating your Pollock

That doesn't mean you can't use a marinade to infuse Alaskan pollock with flavor, but you need to keep it brief. Use fresh herbs or coarsely ground spices to add punch to the marinade, and citrus juice, white wine or good white wine vinegar for the acidity. Place the fish portions and marinade in a heavy-duty plastic bag or layer the fish and marinade into a mixing bowl or food-safe storage container. The pollock should marinate for no longer than 20 minutes, or 30 minutes if the fillets are an inch or more in thickness. Keep the fish refrigerated while it marinates, in the interest of food safety.

Alternative Techniques

An overnight marinade doesn't work well for pollock, but there are other ways to infuse the fish with deep flavors. For example if you coat the fillets with a spice rub containing a small amount of salt, the salt will help convey flavors into the fish overnight. Layering the fillets overnight with fresh herbs such as dill and chives also imparts deep flavors into the pollock without the adverse effects of an acidic marinade. Another alternative is to add flavors as you cook the pollock. The French frequently poach fish in a highly seasoned broth, called court-bouillon, or pollock can be steamed Asian-style on a bed of herbs and aromatic vegetables.