In a 2-cup liquid measure, dissolve yeast and 1 teaspoon sugar in warm water. Let stand until foamy, about 5 minutes.
Insert dough blade in work bowl; add bread flour, whole wheat, rye, wheat germ, caraway seed and salt. Pulse on dough speed to combine, about 2 to 3 times.
Add vegetable oil, molasses and buttermilk to yeast mixture. With machine running on dough speed, add liquid mixture through small feed tube in a steady stream only as fast as flour will absorb it.
Once dough forms a ball, continue processing for 45 seconds to knead dough. Open lid to check dough consistency. If dough is stiff and somewhat dry, add 1 teaspoon water; if soft and sticky, add 1 tablespoon flour. Close lid and process for 10 seconds. Check dough consistency again, making additional adjustments if necessary.