Everyone (hopefully) uses soap of some kind daily. Buying your average bar of soap, however, is pretty expensive, covered in wasteful packaging, and often full of mystery ingredients you probably don’t want on your skin. My partner and I have been making our own soap for many years, which has saved us money, reduced our waste stream, and keeps us feeling confident about what we’re washing with every day. Having experimented with a variety of soap recipes, we have finally settled on one that we love that I hope will inspire you to try making your own soap too.

We use SoapCalc  to figure out the exact proportions of the various oils and lye to use, but assuming you use our recipe below, you won’t have to do any calculations. We also tend to purchase our supplies in big quantities from Wholesale Supplies Plus. For more on the science of lye soap, check out this concise article. This recipe took awhile to develop, because we wanted to avoid using palm oil (here’s why) or any hydrogenated oils (like what you’ll find in Crisco) that are not only heavily processed, but also contribute to the harmful GMO and monoculture world (more info here). These ingredients are very common in soaps, so perfecting an alternative, cruelty-free option took awhile! While not ethically or ecologically perfect, this recipe is the best we’ve come up with.

*Disclaimer: Lye is very dangerous to work with. Please wear safety gear and follow the procedures slowly, carefully, and by reading ahead so you know what to expect. Anything you use that touches lye in this process should not be used for cooking again. Remember that scene in Fight Club? That really illustrates the power of lye. But lye is what makes soap, soap. It’s worth it. 

Materials Needed for 7 Pounds of Soap:

  • Lye Safety Gear: Safety Glasses, Rubber/Vinyl Gloves, Face Mask, Long pants and sleeves
  • Big non-reactive pot and stirring spoon (e.g. stainless steel)
  • Glass pyrex measuring container (8 C or bigger)
  • Kitchen Scale
  • Kitchen Thermometer
  • 1,428.81g (50.4oz) Coconut Oil
  • 793.79g (28oz) Cocoa Butter
  • 952.54g (33.6oz) Olive Oil
  • 1,206.55g (42.56oz by weight) Water
  • 475.63g (16.78oz) Lye Powder/Granules
  • 3.5oz by weight (or 112mL by volume) Essential Oils (e.g. sweet orange, lime, peppermint, rosemary, lavender, etc.–whatever smells you want)
  • Optional Additions: Colorants (like mica for some sparkle, black walnut powder for brown, or spirulina for green), flower petals (calendula is a favorite), cornmeal (for some exfoliation), or oats (for an extra soothing soap)
  • Parchment Paper
  • Soap Mold or Cardboard Box

Procedure:

  1. Weigh your coconut oil, cocoa butter, and olive oil in your big non-reactive pot on your kitchen scale, then melt oils together in that pot on the stove. We weigh in grams instead of ounces since it’s a bit more precise on our scale.
  2. With glass measuring cup on scale, pour in the correct weight of cold water (not volume–weight!)
  3. Wearing your lye safety gear, go outside and weigh your lye in a separate, dry, non-reactive container (glass is great).
  4. Stay outside, keep your safety gear on, and carefully stir container of water while slowly pouring the lye into it. The mixture will get hot–about 200F.  This is the most dangerous part–if you breathe in any of the steam or get any of the lye on your skin, you’ll feel it burn you. Proper safety gear, going slow, and paying attention greatly reduces the riskiness of this moment!
  5. Go back inside and check the temperature of your oil mixture. Wait until the oil mixture and the lye mixture are each about 105-120 degrees F. If lye gets cooler than the oil mixture, compensate by heating the oils up to the lye’s temperature (do NOT try to heat the lye mixture). 
  6. Bring the oil mixture outside and slowly pour the lye mixture into the oil mixture, stirring with a non-reactive spoon.
  7. Once they’re combined, stir vigorously, ideally with an immersion blender that you only use for soap-making, until “trace.” If you don’t know what “trace” means, watch this video, which illustrates Steps 6 and 7.
  8. Add your essential oils.
  9. Add your optional colorants, flower petals, cornmeal, or oats. Add until the texture and/or color “looks right.” This is the one part that I don’t specifically measure. For a swirl of multiple colors (see picture to the right), separate the mixture into multiple containers and color each part separately. Then you can pour, stir, and swirl those colors together as you like.

    HandmadeSoapColored
    Spirulina powder for green, black walnut powder for brown.
  10. Pour the mixture into a parchment paper-lined cardboard box or soap mold and close the lid/cover.
  11. If it’s a hot summer day, throw a towel over it. If it’s a cold day, bundle it up like it’s going for a winter walk. Aim to keep your soap at about 120F. If it is too hot, the glycerin can come out of solution and create surface bubbles and volcanoes. If it stays too cold, the lye won’t finish reacting correctly and may create an ugly yet harmless surface ash. Here are images and explanations for common soap problems.
  12. Clean Up: Hose off outdoor area where you dealt with any lye. Your soap mixture (and any clinging onto pots, spoons, etc.) will remain caustic until it finishes its chemical reaction in 24 hours. Wear gloves when cleaning all your materials (clean thoroughly, with lots of dishsoap and hot water). Reserve those materials for future soapmaking, not food.
  13. Keep your soap insulated for 24 hours.
  14. Uncover, unwrap, and cut into soap bars.
  15. Store bars of soap in a cool place with plenty of air flow between them for one month (4 weeks).
  16. Wrap each bar in butcher paper or put them all together in a ziploc bag. They’ll last forever!
  17. Leave me a comment if you have any questions!
HandmadeSoap
Our results from the above recipe, using calendula petals for some color, texture, and added cleansing.