I've been adding a cup or so of spent barley to each loaf, left over from mashing home brewed beers. This adds a wonderful taste, texture, adds moisture and greatly improves the crumb. My wife insists I do this every time now.
If you don't have access to spent malted barley, then I urge you to look into home brewing you own ales. For one who enjoys the lengthy process of SD baking, home brewing is a natural and heaven sent hobby!