The Latin root for all biscuits means "twice baked." This most accurately refers to what used to be called ship's biscuits or hardtack. These dry, bone- hard slabs of baked flour-and-water paste were designed to keep forever on long ocean voyages. So hard were these biscuits that they were known to break teeth if they were not soaked before they were eaten.
In this country, hardtack is almost extinct. However, the memory of it is kept alive in a Southern recipe for a crisp cracker-type biscuit called Beaten Biscuit, named after the technique of beating the dough with a hammer before cutting it and baking. Such beating makes the dough very firm, increasing the biscuit's shelf life.
Most biscuit recipes start by mixing a leavener with flour and some flavoring and then cutting fat into the dry ingredients as if one were making pie dough.
Southern biscuit recipes almost always call for cake flour. This high- starch, low-protein flour produces biscuits of incredible lightness and tenderness, a lightness belied by the richness of fat in every bite.
The fat used in these biscuits is traditionally lard, but shortening, margarine or butter is more common now. The fat coats the flour so that even after the dough is bound with liquid, the flour particles stay somewhat separate from one other, ensuring that the biscuit stays tender.
Tenderness is further enhanced by adding acid to a biscuit dough. Buttermilk is the most common choice, but yogurt and sour cream do just as well. The positive effect of these liquids on the texture of a biscuit dough is so pronounced that many bakers insist on using buttermilk or sour milk whenever they make biscuits.
