The night before: Sort out any unwanted material (small stones or soil particles, etc.) from the dried pinto and black beans. Rinse beans and place in slow cooker set on “high.” Add the sage, oregano, cilantro, and bay leaves.
Heat the 12 cups of water in the microwave oven, 2 cups at a time, adding it to the beans in the slow cooker.
Before retiring for the night, stir beans and check to make sure the beans are covered with enough hot water. Add more water, if necessary. Reduce heat to “low.”
In the morning, stir beans, and check water level, adding more if desired. Set heat to “high.”
Peel and clean garlic cloves and onions. Remove stems from chipotle peppers. Place garlic, onions, chipotle peppers, and orange juice concentrate in blender. Run covered blender at “high” until contents are creamy. Pour the contents into a microwaveable dish or pot. Rinse out the blender container with a little water and add to the dish. Heat to boiling and add contents to slow cooker and mix in.
Add tomato paste and stir well. Continue to cook until beans are very soft. Mash some of the softened beans against the bottom of the slow cooker with a spoon or potato masher and mix well to have a thicker consistency.