It doesn’t take much because there are no fillers or additives that I suspect they add to commercial detergent. If I have a particularly large or dirty load, sometimes I add more. But usually one scoop does the trick.
*** UPDATE: I have been using this second batch of soap for nearly a year and I don’t like it as well. When I make the next batch in a few months, I will definitely switch back to the Fels Naptha. I think it dissolves better and has more cleaning power than Zote. I will also add the generic store brand Oxyclean back into the mix too. It just works better with the original recipe!