Weigh out 12 ounces of flour and put it in a sifter. Add the baking soda, cream of tartar and salt. Sift all into a bowl. Weigh out 3 ounces of chilled lard and break it into 1- inch chunks. Cut the lard into the flour with 2 knives or a pastry cutter. Fold in the buttermilk in 3 parts. ( Use 1/4 cup more buttermilk if necessary.) Only fold in the buttermilk until it's just blended. Work lightly.
Lightly dust the table with flour. (Use as little flour as possible) Work the dough with fingertips only until it just holds together. Roll out dough 1/2-inch thick. Dip biscuit cutter in flour and punch out 12 biscuits.
Don't use a glass to punch out the biscuits and don't twist the cutter. You need a clean cut that doesn't compress the dough so the biscuits will rise easily.
You can stack scraps and roll them out in order to cut more biscuits. Put biscuits on ungreased baking sheet.
Put the biscuits close together but not touching. If they're too close, the edges won't cook and the biscuits will have a cakey texture - too far apart and they'll brown too soon and be raw in the middle.
Bake at 450 degrees. Until tops are golden brown, about 15 to 17 minutes.