BUTTERMILK BISCUITS
BISCUITS SHARE WITH MUFFINS THE DISTINCTION of being among the simplest of all breads. They are made from a mixture of flour, leavener (baking powder or soda), salt, fat (usually butter or vegetable shortening), and liquid (milk, buttermilk, sour milk, yogurt, or cream). To make them, one cuts fat into the dry ingredients, as when making pie dough; the liquid is then stirred in until a dough forms. Biscuits are usually rolled out and cut, although they can also be shaped by hand or dropped onto a baking sheet by the spoonful.
We began our testing by focusing on the flour. We found that the kind of flour you choose has a great effect on the biscuit you end up with. The main factor here is the proportion of protein in the flour. Low-protein, or "soft," flour (such as cake flour or White Lily, a favored brand in the South) encourages a tender, cakelike texture as well as a more moist crumb. Higher-protein, or "strong," flour (such as all-purpose flour) promotes a crispier crust and a drier, denser crumb.
Tasters liked the crispier crust of the biscuits made with all-purpose flour and the tender, airy crumb of the biscuits made with cake flour. We found that a combination of half cake flour and half all-purpose flour delivered the best results—a crisp crust and a tender crumb. If you don't have cake flour, all-purpose flour makes a fine biscuit as long as you add more liquid to the batter.
Fat makes biscuits (and other pastries) tender, moist, smooth, and tasty. Butter, of course, delivers the best flavor, while vegetable shortening makes a slightly flakier biscuit with better holding powers. However, we don't think this gain in shelf life is worth the loss in flavor. Stick with unsalted butter when making biscuits.
We discovered that a proportion of 1/2 cup fat to 2 cups flour provides the best balance of tenderness and richness with structure. If you use less fat, your biscuits will rise well, but they will be tough and dry. If you use more, your biscuits will have a lovely texture but they may end up a bit squat.
After mixing flour and leavening, you must "rub" the fat into the dry ingredients, making a dry, coarse mixture akin to large bread crumbs or rolled oats, with some slightly bigger lumps mixed in. This rubbing may seem unimportant, but in fact it is crucial to the proper rising of the biscuits. Gas released by the leavening during baking must have a space in which to collect; if the texture of the dough is homogeneous, the gas will simply dissipate. Melting fat particles create convenient spaces in which the gas can collect, form a bubble, and produce a rise. Proper rubbing breaks the fat into tiny bits and disperses it throughout the dough. As the fat melts during baking, its place is taken up by gas and steam, which expand and push the dough up. The wider the dispersal of the fat, the more even the rising of the dough.
If, however, the fat softens and binds with the dry ingredients during rubbing, it forms a pasty goo, the spaces collapse, and the biscuits become leaden. To produce light, airy biscuits, the fat must remain cold and firm, which means rubbing must be deft and quick. Traditionally, biscuit makers pinch the cut-up fat into the dry ingredients, using only their fingertips—never the whole hand, which is too warm—and they pinch hard and fast, practically flinging the little bits of flour and fat into the bowl after each pinch. Less experienced cooks sometimes cut in the fat by scraping two knives in opposite directions or by using a bow-shaped pastry blender. We found, however, that there is no reason not to use the food processor for this task: pulsing the dry ingredients and the fat is fast and almost foolproof.
After cutting in the fat, liquid is added and the dough is stirred, just until the ingredients are bound, using a light hand so the gluten will not become activated. We found that buttermilk (or plain yogurt) gives biscuits the best flavor. It also creates a lighter, airier texture than regular milk. That's because the acid in the buttermilk reacts with the leaveners to increase the rise.
Biscuits are best formed by gently patting gobs of dough between your hands. If the work surface, the dough, and the cutter are generously floured, fluffy biscuits can be rolled and cut; but the softness of the dough makes this a tricky procedure, and the extra flour and handling will make the biscuits heavier and somewhat dense.
Because they need quick heat, biscuits are best baked in the middle of the oven. Placed too close to the bottom, they burn on the underside and remain pale on top; set too near the oven roof, they do not rise well because the outside hardens into a shell before the inside has had a chance to rise properly. As soon as they are light brown, they are done. Be careful, as over-cooking will dry them out. Biscuits are always at their best when served as soon as they come out of the oven. The dough, however, may be made some hours in advance and baked when needed; the biscuits will still rise well.