This batch of 80% rye, ended up with a sweet little crumb. The wheat gluten, (20%), really helps the loaf structure. I used a rye/ww mother for leavening, and was pleasantly surprised at the oven spring. The crumb is irregular, like typical levain, and quite moist , like a traditional rye.. The pleasant, but glaring difference, is the openness of the crumb. Makes for a really nice-sized slice for deli-sized sandwiches. Once again, All hail the sourdough!