2 cups flour
                    2 teaspoons baking powder
                    ½ teaspoon baking soda
                    ½ teaspoon salt
                    1 tablespoon sugar
                    6 tablespoons unsalted butter
                    2/3 cup buttermilk
                    flour or buttermilk, for topping

                    These biscuits have a slightly tangy flavor and tender crumb because of
                    the buttermilk. To create carbon dioxide, the gas that makes biscuits
                    rise, the acid in the buttermilk must be balanced with an alkali, usually
                    baking soda.

                    Preheat oven to 425°. Butter and flour a baking sheet or line with
                    baking parchment.

                    Mix flour, baking powder, baking soda, sugar and salt. With a pastry
                    blender or fingers, cut butter into biscuit mix until mixture is the
                    consistency of fine crumbs. Pour in buttermilk and stir to mix. As soon
                    as mixture holds together, turn out onto a floured work surface and
                    knead lightly.

                    Roll or pat dough to a thickness of ½ to ¾ inch; cut into 2 ½-inch
                    rounds with a floured cutter.

                    For crustier biscuits, place rounds about 1 inch apart on prepared
                    baking sheet. For softer sides set touching or ¼ inch apart. Brush
                    lightly with flour or buttermilk and bake until golden brown (10 to 12
                    minutes).

                    Makes about 16 biscuits.