Superfatting your soap simply means adding an excess amount of oil or discounting your lye amount so you end up with an excess amount of oil. You’ll hear it both referred to as superfatting or lye discounting. This excess oil provides your soap with unsaponified oils to give your soaps moisturizing or emollient properties. This process also acts as a type of “insurance” or “buffer” making sure that your soap will not come out lye heavy. A good range for superfatting is typically 3-8%. If you go below that you could end up with lye heavy soap or soap that is generally too harsh.

If you superfat with high percentages you are left with high amounts of unsaponified oils in your soap. While soap tends to have a pretty long shelf life, oils don’t and will go rancid. So a higher superfatted soap tends to go rancid quickly. A soap calculator will have an input field for superfatting and will calculate this for you. As you can see below the lower the superfat or lye discount the higher amount of lye is used. The higher the amount of superfat or lye discount the lesser amount of lye is used leaving a higher content of unsaponifed oils.

Recipe with no lye discount
8 oz olive oil
4 oz palm oil
4 oz coconut oil
2.384 oz lye

Recipe with 5% lye discount
8 oz olive oil
4 oz palm oil
4 oz coconut oil
2.265 oz lye

Recipe with 8% lye discount
8 oz olive oil
4 oz palm oil
4 oz coconut oil
2.194 oz lye

As always, be sure to use a reliable soap calculator like!

Join Soap Week Update!
Join Soap Week Update for coupon codes and to stay up to date with the latest tips and soap making tutorials in the industry!
We respect your privacy.

Thanks for being a part of the Lovin’ Soap community! We’re so glad you’re here!

Now through March 1st, we are having a presale on our newest eClass, Clear Transparent Soap from Scratch!

In this video eCourse, I will show you:

  • How to formulate your own transparent soap recipe that is remelt-able and reusable…similar to MP soap base.
  • We’ll go over base oils and solvents that are available to use and why you would select each type of ingredient.
  • How to make quick hot process transparent soap from scratch. It only takes about 20 minutes once you get the process down!
  • How to remelt and use your base for future projects.

About the soap:

  • The ingredients we use include coconut oil, stearic acid, castor oil, sodium hydroxide, everclear (grain alcohol) and sugar.
  • The soap is remeltable and you can work with it like melt and pour soap base.
  • You can create bars of soap or embeds that you can add to regular cold process soap.
  • You’ll get different varieties of clarity in your soap…we’ll talk about that.

The class will be delivered in a a series of videos and downloadable PDF’s. You’ll have forever access and be able to watch over and over again as you want.

Happy Soaping! -Amanda Aaron