Measure flour and pepper into a clean, dry food processor and pulse to mix. Add shortening and continue pulsing until mixture is crumbly like cornmeal.
Add sauerkraut gradually, blending after each addition, until entire 2 cups has been added. The mixture should be a dough ball in the processor now.
Turn the dough ball out onto a floured surface. Pull off tablespoon-sized balls and roll them smooth. Place balls on the greased cookie sheets and flatten with the bottom of a drinking glass, to about ¼-inch thickness.
Place cookie sheets in preheated oven and bake for 10 minutes, watching closely and turning crackers as necessary. After 10 minutes, reduce oven temperature to 350°F and bake 10-15 minutes more.
Remove crackers from oven, scoop onto a cooling rack and cool undisturbed. Once cooled, store in an airtight container.