The reason for the incredible versatility of yogurt and buttermilk is, in large part, because they are in flux themselves. Both are made from low-fat milk to which a bacterial culture has been added. The bacteria feed off the natural sugars in the milk and produce lactic acid as a byproduct of that metabolism. As the acid builds up in the milk, it begins to clabber the milk protein into curds, causing the milk to thicken. When a desired consistency is reached, the fermenting milk is chilled, retarding the action of the bacteria. Lactic-acid production slows, and the thickness and acidity of the yogurt or buttermilk are set.
It's this natural thickness and pleasant tang that many nutrition-focused cooks find so useful. Yogurt and buttermilk allow them to make sauces and soups without additional thickeners and to spark the flavor of countless dishes without undesirable salting or tedious seasoning.
One of the most magical aspects of these products is how they make baked goods, from pancakes to coffee cakes, lighter in texture and softer in consistency. Acidic ingredients, like buttermilk and yogurt, naturally soften the structure of a baked good by denaturing the protein in the batter. Because the buildup of proteins in a cake or pastry creates toughness, buttermilk and yogurt act as tenderizing agents.
That's why buttermilk biscuits are so much lighter and more tender than other types. It's why a bit of yogurt in a cake batter will make the cake fluffier, or why a drop of buttermilk in a pastry dough will keep the flake of the crust light and soft.
Don't overdo it, though. Too much acid in a pie crust, for instance, can make it so soft that it loses its flake altogether. Too much yogurt or buttermilk added to a cake batter can alter the acid and base balance of the cake to such a degree that it can disrupt the rising action of the baking powder in the recipe. Therefore, when in doubt, use a recipe designed for the use of fermented dairy products rather than using a recipe converted on your own.
The fresh zing of yogurt- and buttermilk-based dishes is just the thing to take the swelter out of a summer day. The following recipes have been designed to include a minimum of cooking.
CHILLED BUTTERMILK CUCUMBER SOUP
1 cup chopped onion
1 clove garlic, minced
1 tablespoon peanut oil
2 large cucumbers, peeled, seeded and diced
1 cup chicken stock
2 tablespoons chopped fresh dill weed
Salt and cayenne pepper to taste
2 cups buttermilk
1 tablespoon white wine vinegar
In a heavy saucepan, gently cook the onion and garlic in the oil until they begin to soften. Add the cucumbers, and continue to cook, stirring frequently, until they begin to release their moisture.
Add the stock, dill, salt and cayenne, and simmer until the cucumbers soften, about five minutes. Remove from the heat, and allow to cool. Add the buttermilk and vinegar. Stir well, and chill thoroughly. Adjust seasoning and
serve in chilled bowls. Makes four servings.
STEAMED FISH WITH YOGURT HERB SAUCE
4 filets of lean fish (orange ruff, snapper or black bass)
Salt and pepper to taste
1/4 cup chopped fresh herbs (basil, tarragon, thyme, dill, mint)
2 tablespoons chopped parsley
1/4 cup finely chopped onion
1 teaspoon olive oil
1/2 cup fish stock, clam juice or white wine
1 cup yogurt
Season the filets on all sides with salt and pepper. Mix the quarter-cup of fresh herbs with the parsley, and sprinkle each filet with a tablespoon of the herb mix. Wrap each filet well in plastic wrap. Refrigerate until ready to cook. Reserve remaining herbs.
In a skillet, saute the onion and garlic in the olive oil until softened. Add the fish stock, clam juice or wine, and reduce until about three tablespoons of liquid remain in the pan. Set aside.
Steam the plastic-wrapped fish over boiling water for six to eight minutes. When the fish flakes slightly to gentle pressure, snip the end from the plastic wrapper of each fish and drain the juices in the package into the skillet. Over high heat, reduce the liquid in the skillet to about one-quarter cup. Remove from the heat, and swirl in the yogurt and the remaining chopped herbs. Remove the fish from its wrappers, and nap with the yogurt sauce. Makes four servings.
SHRIMP IN SPICY BUTTERMILK PEANUT SAUCE
2 teaspoons peanut oil
1 pound large shrimp
2 scallions, thinly sliced
1 teaspoon Oriental chili paste
2 teaspoons light soy sauce
2 teaspoons grated fresh gingerroot
1/2 teaspoon ground cumin
1/2 teaspoon ground coriander
1/4 cup natural-style crunchy peanut butter
1 cup buttermilk
In a nonstick skillet, heat half the oil. Add the shrimp, and cook quickly until the shells of the shrimp color fully. Remove the shrimp, shell them and clean them. Set aside.
Add the remaining oil to the skillet, and heat slightly. Add the onion and garlic, and cook over moderate heat until lightly softened. Add the scallions, chili paste, soy sauce, ginger, cumin and coriander. Cook for two minutes.
Stir in the peanut butter, and heat until the peanut butter has melted.
Over very low heat, stir in the buttermilk. Add the shrimp, and heat through. Do not allow to boil. Serve over rice. Makes four servings.
FROZEN IRISH COFFEE YOGURT
3/4 cup sugar
1/4 cup water
3 tablespoons instant coffee powder
1/4 cup Irish whiskey
1/4 teaspoon ground cinnamon
1 quart coffee yogurt
In a heavy saucepan, combine the sugar and water, and stir well. Bring to a boil, and stir in the instant coffee powder. Remove from the heat, and stir in the whiskey and the cinnamon. Chill thoroughly.
Combine this mixture with the yogurt and salt, and freeze in an ice-cream freezer, according to the manufacturer's directions. Makes about one quart, or four servings.
FRUIT AND YOGURT SHAKE
1 cup chopped fruit (berries, bananas, apple, pear, mango, etc.)
1 cup plain, vanilla or lemon yogurt
Chill all ingredients well. Puree the fruit in a blender or food processor, and add the yogurt. Blend until homogenous and foamy. Serve chilled. Makes one serving.
STRAWBERRY 'CHEESE' PIE
6 cups vanilla yogurt
1 cup lemon yogurt
1 pre-baked 9- to 10-inch pie shell
1 quart strawberries, blueberries or raspberries
10 mint leaves, for garnish (optional)
Line a strainer with four layers of cheesecloth, and set over a deep bowl. Mix the vanilla and lemon yogurts together, and place in the cheesecloth-lined strainer. Wrap the excess cheesecloth over top. Cover with a plate, and place a light weight on the plate. Refrigerate for 12 to 18 hours until very thick.
Scoop one-third of the drained yogurt from the strainer, and spread into an even layer in the bottom of the pie shell. If using strawberries, slice half of them. Arrange half the sliced strawberries or one-quarter of the blueberries or raspberries on the layer of yogurt in the pie shell. Top with another one-third of the yogurt, followed by another layer of berries. Top with the remaining yogurt. Arrange the remaining whole berries on top of the pie in concentric circles.
Garnish with mint leaves, if desired. Refrigerate until ready to serve. Makes 10 servings.