Sour milk waffles are a type of waffle that is made with sour milk instead of regular milk. The sour milk gives the waffles a slightly tangy flavor and makes them slightly more dense than regular waffles.
Sift flour, measure, and sift with salt and baking soda. Beat egg yolks until light and foamy. Add sugar and shortening. Mix well. Add milk alternately with sifted dry ingredients to egg mixture. Fold in stiffly beaten egg whites. Bake in hot waffle iron.