Buttermilk Cake A favorite genre of cakes was white cake, made with egg whites (lots of them), soft white winter wheat flour, sugar, butter, baking soda and cream of tartar. There were many variations of the formula, all aiming to get a light crumb, sweet flavor, and white appearance. Often covered in white icing, the standard white cake was a fixture on the sideboard of a polite parlor prior to 1950. Some sought to make the flavor more plush by adding vanilla to the mix. But there was more than a whiff of artifice to this path of white cake making. A solider path to a rich tasking white cake was to make buttermilk an ingredient, which with cream of tartar and baking soda would activate enough gas to aerate the crumb of the cake.
So would the egg whites be whipped before being added to the batter?