The recipes we have have listed have the exact amount of lye to make soap that contains very little excess fat. This soap leaves skin perfectly clean and smooth feeling. Some people like excess fat in recipes. For this I recommend 2 to 4 tablespoons castor oil added when the soap traces. Castor oil is emollient and contributes to soap lather. Adding castor oil after tracing along with 1 tablespoon essential oil also seems to help retain the soap fragrance. To superfat with other fats, you can subtract about .2 oz weight lye from one lb. batches of soap recipes which allows excess fat to remain.