The Marin County Jail will start baking its own whole-wheat bread to reduce costs by about $41,000 annually once Marin recoups the cost of the baking infrastructure—a mixer, a slicer, a water meter and a large oven that can bake 45 loaves at a time—the county announced this week. The new bakery will also improve the nutritional intake of inmates, who consume about 38,000 loaves of bread a year. The purchased loaves came at a…