Cut in butter with a pastry blender until mixture resembles coarse meal. Gradually add sour cream, stirring until dry ingredients are moistened. (Dough will be stiff.)
Turn dough out onto a lightly floured surface, and knead 10 to 12 times.
Roll dough to 1/2-inch thickness, and cut with a 1 3/4-inch biscuit cutter.
Place biscuits on a greased baking sheet.
Bake at 450 for 12 minutes or until lightly browned.