Heat beans and water to boiling in 4-quart Dutch oven; reduce heat. Simmer uncovered 10 minutes; remove from heat. Cover and let stand 1 hour.
Drain beans. Place beans and remaining ingredients except sour cream and cilantro in 6-quart slow cooker.
Cover and cook on Low heat setting 10 to 12 hours.
Serve soup topped with sour cream and cilantro.