SEAFOOD STEWS

FIND A COUNTRY THAT HAS A COASTLINE, AND you will find a fish stew in the culinary repertoire. Whatever their geographic origin, fish stews are surprisingly easy for home cooks to prepare. Most recipes begin by making stock. The next step is to make a flavor base. The stock is added and then the fish.

Although the process is straightforward, we had a number of questions. Is fish stock essential? If so, what kinds of fish make the best stock? What ingredients are essential in the flavor base and which are optional? What kinds of fish respond best to stewing? What size should the pieces of fish be? How long should they cook?

We started our testing by making a favorite fish stew with homemade fish stock, water, chicken stock, and a "cheater's" stock that started with bottled clam juice. The stew made with homemade fish stock was far superior. Unlike meat or chicken stews, where the protein simmers for some time in the stew, fish can cook for only a few minutes or it will dry out and fall apart. Since the fish does not have time to flavor the stew liquid, the liquid must start out tasting good. Water made a horrible fish stew. Chicken stock tasted too much like chicken. Bottled clam juice, doctored up with some fresh ingredients, is our second choice if making fish stock is impossible.

We tested various fish for making stock and preferred those with heads and bones that will produce a gelatinous stock. (See Choosing Fish for Stock for more details.) Trimmings can come from any number of fish, although oily, strong-tasting fish, such as bluefish or salmon, should be avoided.

Many recipes suggest sweating fish bones and vegetables before adding water to make stock. In our tests, we found that this step was not only unnecessary but also yielded an inferior stock. We found that simply adding all the ingredients to the pot, including the water, at the same time, produces a cleaner, brighter tasting stock.

Unlike meat or chicken stock, fish stock is rarely simmered for hours. Some sources warn against simmering for longer than 15 or 30 minutes, suggesting that the trimmings will make the stock bitter if cooked too long. We tested various times and found that fish stock tastes best when simmered for a full hour. When we continued to simmer the stock for another hour there was no improvement in flavor, but the stock did not become bitter, either.

There was a time when fishmongers would gladly give away bones, heads, and tails. But no longer, unless perhaps you are an especially good customer. And don't expect to automatically have bones available when you show up. Call ahead and reserve what you need.

In addition to fish trimmings, water, and aromatic vegetables, many recipes call for white wine. We made fish stock both with and without wine and found that the wine adds a pleasant acidity. (Adding a little lemon adds some acidity, but not enough. We found that adding more than a quarter of a lemon will make the stock taste overly lemony.)

The prime flavoring element for many fish stews is a seasoned tomato sauce, or base. Like stock, aromatic vegetables (onions, carrots, and celery) add flavor. However, for the base these vegetables should be sautéed to bring out their full flavor. Again, white wine brings a much-needed acidic edge to the stew. Other ingredients, such as fresh fennel and Pernod for bouillabaisse or almonds and red bell pepper for zarzuela, are added to give specific stews their character. Whatever the ingredients, the base should be well seasoned; it will be diluted with fish stock, which is cooked without salt.

We tested bases made with fresh and canned tomatoes. We found little difference, so don't hesitate to use canned tomatoes. Unlike the stock, the base for the stew doesn't improve with longer cooking. After twenty minutes, the tomatoes begin to lose their freshness. After thirty minutes, the tomato base tastes too acidic and all the fresh tomato flavor is gone. Once the tomatoes are added, we recommend simmering the stew base just long enough to thicken the consistency and blend flavors, 15 to 20 minutes.

Once the base is cooked, it's time to add the stock and bring the mixture to a boil. The fish is then added and cooked briefly. In our testing, we found that overcooking the fish is the biggest problem with most fish stews. We found that 3-to 4-ounce pieces are best for serving (they are neither too large to eat gracefully nor so small that they fall apart in the stew). Pieces of fish this small, however, cook very quickly. We tried various simmering and boiling regimens. In the end, what worked best was cooking the fish in simmering broth for 5 minutes, followed by 5 minutes of indirect cooking with the heat turned off and the lid on the pot.

Any white-fleshed fillet can be used in fish stew. In general, we like firmer fillets, such as red snapper or monkfish. Tender fillets, such as flounder or sole, can be used, but you might want to reduce the simmering time by a minute or two to keep these thinner fillets from overcooking.

CHOOSING FISH FOR STOCK

Several kinds of fish make an exceptionally good stock that is rich and gelatinous. These fish are listed in the first grouping and should be used when possible. Most other tender white fish are fine for stock as well, and these are listed in the second grouping. Avoid the oily fish in the third grouping when making stock.

BEST FISH FOR STOCK

COMMON FISH THAT MAKE GOOD STOCK

FISH TO AVOID