1In a small bowl, blend the sour cream and baking soda, and set aside.
2Preheat oven to 350 degrees F (175 degrees C). Lightly grease a large baking sheet.
3In a large bowl, mix the flour, sugar, baking powder, cream of tartar, and salt. Cut in the butter. Stir the sour cream mixture and egg into the flour mixture until just moistened. Mix in the raisins.
4Turn dough out onto a lightly floured surface, and knead briefly. Roll or pat dough into a 3/4 inch thick round. Cut into 12 wedges, and place them 2 inches apart on the prepared baking sheet.
5Bake 12 to 15 minutes in the preheated oven, until golden brown on the bottom.
Footnotes
Tip
Aluminum foil can be used to keep food moist, cook it evenly, and make clean-up easier.