Preheat oven to 450°F In a small bowl, stir together buttermilk and lemon peel. In a bowl, whisk together flour, baking powder, sugar, coriander, baking soda, salt and pepper. Cut in butter, using your fingers, 2 knives or a pastry cutter until mixture resembles coarse meal.
Make a well in center of flour mixture and pour in buttermilk mixture. Toss with a fork, scraping dry ingredients from bottom until just evenly moistened; do not overmix (dough should be very sticky). Turn dough out onto a floured surface and knead lightly once or twice with floured hands. Pat dough to 3/4-inch thickness, about 10 inches in diameter.
Dip a 2 1/2-inch biscuit cutter into flour and cut out biscuits, dipping cutter into flour before cutting each biscuit and using a straight in-and-out motion. Gather and re-pat scraps; cut out remaining biscuits. Transfer biscuits to an ungreased baking sheet and bake, rotating pan halfway through, until golden, 12 to 15 minutes. Serve warm.