Several thousand years ago, people discovered that exposing fish to intense amounts of salt and smoke was a great of preserving the catch for later.

Today, our smoking techniques are considerably more refined, and we do it more for flavor than as a means of preservation.

Which makes it a shame that more people don’t think to reach for smoked fish as an effortless way to add gobs of flavor to the foods they love.

But first, a primer on smoked fish. There are two ways to smoke: cold and hot. Salmon, trout, haddock and mackerel are the most common choices.

In cold smoking, the fish are brined in a heavy salt solution, then exposed to cool smoke (85 degrees F max) for up to several days, then frozen to kill parasites.

Cold smoked fish — which is essentially raw — has a soft, delicate texture, an assertive saltiness and a pleasant, but not overwhelming, smoky flavor.

Hot smoked fish is more lightly brined, then smoked for a shorter time at a higher temperature (as high as 170 degrees F), effectively cooking the fish.

Hot smoking produces a fish with a more assertive smoky flavor and a meatier texture (though the lighter brine means it isn’t as salty).

Both varieties often are seasoned, often with just a bit of sugar, but sometimes with black pepper, dill or other herbs.

So long as you bear in mind the differences in saltiness and smokiness, hot and cold smoked fish often can be used interchangeably in recipes.

Generally, neither variety should be exposed to long cooking times, especially hot smoked fish, which already is cooked.

The exception to this is certain baked recipes, such as fish cakes and fish pot pies, which usually contain enough moisture to prevent the fish from getting tough.

Grocers generally sell a wide variety of both types of smoked fish.

Salmon, for example, can be found with different seasonings and cuts, including thinly sliced, thick slabs and whole sides.

Smoked salmon is particularly good for making dips and pâtés. When doing so, look for cheaper packages labeled “trimmings,” which are small pieces.

Thinly sliced salmon is delicious topped with poached eggs and fresh dill.

Hot smoked fish, such as trout and mackerel, are delicious flaked into salads or tossed with warm pasta, especially with a cream sauce.

• Add flaked smoked trout to potato salad. Or serve it broken up over cooked beets tossed with lemon juice and fresh dill.

• To seriously boost the flavor of fish or crab cakes, substitute any variety of smoked fish for some of the fresh fish the recipe calls for.

• In a food processor, puree a package of cold smoked salmon trimmings and a package of cream cheese. Use as a sandwich spread. Also try it with jalapenos or hot sauce added.

• Toss cooked pasta with cream cheese or crème fraiche, chopped scallions, flaked smoked salmon, salt, pepper and a bit of the hot pasta cooking water.

• Add flaked smoked trout to your favorite tuna salad. Or use it in place of the tuna (or some of the tuna) in a tuna casserole.

Not as strange as it sounds. Smoked trout has a meaty texture similar to chicken. And the rich, smoky flavor is the perfect match for a soup thick with noodles.

In a large saucepan over medium-high heat, heat the oil. Add the garlic, carrots, onion, celery, peas, thyme and rosemary. Sauté for 5 minutes.

Add the chicken broth and bring to a simmer. Add the pasta and cook for 7 to 8 minutes, or until barely tender. Remove and discard the rosemary stem. Add the spinach and scallions and heat 30 seconds. Season with salt and pepper.

Using a fork, flake and break up the trout into large bite-sized chunks. Ladle the soup into serving bowls, then pile a bit of the trout in the center of each.

Nutrition information per serving (values are rounded to the nearest whole number): 320 calories; 80 calories from fat (25 percent of total calories); 9 g fat (2 g saturated; 0 g trans fats); 35 mg cholesterol; 41 g carbohydrate; 18 g protein; 5 g fiber; 630 mg sodium.

J.M. Hirsch is the national food editor for The Associated Press. He is the author of the recent cookbook High Flavor, Low Labor: Reinventing Weeknight Cooking . He also blogs at LunchBoxBlues.com.