Introduction: Make "Lye-Free" Liquid Castile Soap From Your Kitchen

This particular recipe is a base process to start making your own liquid castile soap from home.  It is repeated in several articles, books, and internet sites as being “lye-free” However, please keep in mind that all soap has had some form of lye in it at one point or another (if you can find a recipe that is completely “lye-free” during the WHOLE process we would like to know).  The goal here is to remove all the lye during saponification so you will not have any left in your final batch.  We want you to feel free to experiment with different oils however, to keep it “lye-free” use the measurements of the oil, water and KOH (potassium hydroxide) as stated below.

Step 1: Materials Needed

*  47 oz organic olive oil (technicallycastile soapis only made from olive oil but, feel free to try something completely different)
*  32.9 distilled water
*  9.39 oz KOH (potassium hydroxide)(where we get ours)
*  (Later at dilution) 80 oz of distilled water

(all pots, spoons, bowls etc. make sure they are stainless steel and/or heat safe)

*  Slowcooker (one that you will only use for soap, do not use again for food)
*  Accurate scale
*  Stick blender, immersion blender
*  Large stainless steel pot
*  Spoons
*  Bowl(s)
*  Vinegar
*  Gloves
*  Goggles
*  Hat
*  Containers to store your soap
*  Notepad and pen

Make sure you can set aside enough time during the day to give attention to your project without any distractions (easier said than done), have all of your materials ready to go, and ingredients already measured in safe and covered containers.

Step 2: Remember the Movie Fight Club? Yea…they Were Using KOH

Intended for educational purposes only
Image source Fight Club. Director David Fincher. 20th Century Fox, 1999, film
(Click here if you do not see animation)

First Aid for KOH

If KOH is in contact with your skin, first treat the area by rinsing with vinegar and then water for 10-15 mins.  Contact with the eye can cause severe damage and even blindness so, it is great to keep an eyewash solution nearby in a squirt bottle (can be made of distilled water or a sterile saline solution)  Rinse infected eye out with the eyewash solution for at least 10 mins.  Have a phone nearby with the number to poison control center ready.

Find a local center near you

National Hotline 1-800-222-1222

Step 3: Waiting on Naptime...

Keep children and pets away from your work area and make sure the room is well ventilated.

Step 4: "Suit Up"

You will be working with lye and an immersion blender so, we recommend that you wear long sleeves, a hat, gloves and goggles during the complete process.

Step 5: Warm Up

Okay, Let's Go!

Start with 47 oz of olive oil in your slowcooker with the setting on low.

Step 6:

In a stainless steel pot, fill with the 32.9 oz of distilled water and place it on a heat safe surface. Get ready to pour the 9.39 oz lye into the water. Repeat: pour the lye into the water, DO NOT pour the water into the lye!

Step 7: Go Slow

Pour very slowly and be careful that you do not splash the mixture around or breathe in any of the vapors that begin to rise up.

Step 8: Lye Into the Oil

Slowly pour the lye/water mixture into the slowcooker and stir with your heat safe spoon.  It’s really cool watching the oil become cloudy when you add the lye.

Step 9: Stir Forever

Use your immersion blender to stir, stir, and keep on stirring. This is where you put all the work into it. Don’t give up and be careful of splashing.

Step 10: Trace

In about an hour and a half you should have it at such a thick consistency that it seems to “trace” the path of your mixer.
Once your soap is at this point we need to let it sit and do its thing. Put a lid on it and in every 20 mins,  slowly stir it back up.

Step 11: Thickening

Your mixture is going to get thick (kinda the point) so go ahead and put up the immersion blender and use your heat safe spoon from here on out.  Besides, using the blender at this point will only add more oxygen and cause the soap to fluff up.

Step 12: Keep on Going

You want to get it to the point where it is translucent and thick and this may take a couple of hours of getting up and down to check on it. Be patient…

Step 13: Testing

To test your base to see if it is ready, pour 1 cup of hot water into a glass and stir in a small sample of your paste.

Step 14: Can You Read It?

If you can still see thru your glass then it is ready otherwise, chill out and let chemistry do its thing.

Step 15: Transfer

After you have tested your paste, place it into your large stainless steel pot.

Step 16: Dilution

We are going to add a total of 80 oz of hot/boiling water on top of the paste and GENTLY stir the water in (just a little bit).  Cover the pot and let it sit overnight to settle.  You want it to calm down and slowly dissolve into the water

Step 17: There You Go...

Congrats to you!!!
You should have woken up this morning with your own homemade liquid soap:)  If you want to make sure that the soap is fully cured and the lye is no longer active, wait 3-4 weeks before use.

Once again this is only a basic liquid castile soap and it is a great place to start.  From here you can experiment with scents, oils, dilution etc…

Open Source Soap Co.
OSSC is starting from the beginning to develop a liquid base soap that is versatile in your home, easy on your wallet and kind to our environment.  We are testing, documenting and sharing our process along the way because, we believe that everyone should have the right to know what is in their products and how they are made.

Basic "Lye Free" Liquid Castile Soap
-An all around great basic cleaner with only 3 ingredients used.  Great start for beginners.
This is a from scratch recipe that uses KOH potassium hydroxide lye and should not be attempted unless you will take it seriously and follow all the safety precautions.

Next project?

Foam Pump Mason Jar Soap Dispenser
Create your own foam pump mason jar soap dispenser from material that you may already have in your home.  Did you know that the foam soap that you buy at the store contains mostly water? And that it is actually the pump itself that creates the majority of the foam? Save yourself some money by diluting 6 parts water to 1 part of your favorite liquid soap