White Mountain Frosting Be The First To Review By Anonymous recipe Comments | 0 Favorites | 12 Print This is a very good frosting. You may flavor it with any flavoring extract to suit your needs. White Mountain Frosting Ingredients 3 cups white sugar1 cup water1/4 teaspoon cream of tartar3 egg whites1 pinch salt1 teaspoon vanilla extract Instructions 1 Combine sugar, water, and cream of tartar in a saucepan. Cook until candy thermometer reaches 238 degrees F (115 degrees C), or until syrup spins a long thread when dripped from a spoon. 2 Beat egg whites until stiff. Pour a thin, slow stream of the syrup into egg whites, beating constantly until frosting stands in peaks. Stir in salt and vanilla to taste.