Place beans in the crockpot or a bowl, add 8 cups of warm water and the whey, apple cider vinegar or lemon juice. Soak overnight (8-12 hours).
Pour beans into a colander, rinse with filtered water, then place them back into the crock pot.
Place onion, jalapeno pepper, salt, pepper, cumin and chili powder in the crockpot. Cover with water. They should be nice and plump already from soaking and so will not expand much, but make sure they are well-covered. Set on high for 8 hours.
Once the beans are tender, strain them and reserve the liquid. Use a potato masher or mallet to mash the beans. If they are too dry, add some of the reserve liquid.
Add more salt if needed.