I had a large cow butchered some years back and ended up with a whole lot of fat. I made a lot of some very strong soap with it. Sodium tallowate. I think I had 25 - 30#s of the stuff. Used it for laundry, too harsh for the hands.
Tallow is a good soaping fat. You must not have done a lye discount which is why you had great laundry soap.