1 cup sugar
1 tablespoon white vinegar
1 cup dark corn syrup
1 tablespoon baking soda
Line bottom and sides a 9-inch square baking pan with lightly buttered aluminum foil. Set aside.
Combine sugar, corn syrup and vinegar in a large, heavy cooking pot. Cook over medium heat, stirring constantly, until sugar dissolves. Continue cooking to 300*F (150*C) on a candy thermometer. (A small amount of syrup will separate into brittle threads when dropped into cold water.)
Remove from heat and stir in baking soda, mixing well. Mixture will foam up. Quickly pour into prepared pan. Allow to set at room temperature until firm. Invert pan and peel off foil. Break into pieces.Store tightly covered at room temperature.
Makes about 1/2 pound candy.