Combine dry ingredients: In a large bowl add the flour, salt, baking powder and baking soda and mix it all. To it add the cubed or grated butter.
Make the dough: Using a pastry cutter or 2 knives, cut in the butter until the mixture resembles coarse meal. If using grated butter, you just have to mix the butter in with the flour. Next, add the buttermilk to the bowl. Stir in the buttermilk until just moist and knead the dough a few times.
Cut the biscuits: Transfer the dough to a floured surface and knead it a couple times just until it comes together. Don't over-work it as it will start melting the butter. Roll out the dough to 1/2 to 3/4 inch thickness, and cut with a 2 inch biscuit cutter. You should get about 12 biscuits. Place the biscuits on an ungreased baking sheet and brush with egg wash. You can also place the biscuits into a buttered skillet.
Transfer the baking sheet or skillet to the oven and bake for about 10 to 15 minutes or until nice and golden.
Always use cold ingredients! This is the key to a flaky biscuits with separate layers. I usually don’t take anything out of the fridge until I’m ready to use that ingredient in the recipe.
Do not over knead and be gentle. The more you work your dough, the more gluten you develop, and the more gluten you develop the tougher your biscuit will be and more prone to shrinking. Remember, treat it with love and be gentle.
Use fresh ingredients, specifically your baking powder and baking soda. The baking powder is what helps the biscuit layers puff up.
These biscuits will stay fresh for up to 3 days in covered and stored at room temperature.
They also freeze well, just be sure to freeze them spaced evenly on a cookie sheet before placing in a freezer bag or airtight container. This method will allow them to stay fresh for up to 3 months.