Dissolve yeast in warm water.
Sift dry ingredients in large bowl and cut in shortening. Add yeast and milk, mixing well. Knead quickly 20-30 times.
Roll and cut out. Allow to rise 10 minutes. Bake at 400 for 12-15 minutes.
Dough can be stored several days in refrigerator and made into biscuits, allowing 15-20 minutes to rise. To freeze: roll and cut and place on cookie sheet until frozen. Then put in freezer bags. To bake, don't thaw. Place biscuits in oven. Turn to 400; bake until golden brown. Biscuits will rise as oven heats.