DIY Liquid Castile Soap

I have been using Bronners soap for decades. I was first introduced to it when I worked at a health food store here in Columbus, OH called The Raisin Rack. I picked the Peppermint soap randomly and it’s been my go to favorite over the years. I have used it as a shower soap, hand soap, shampoo and even as a toothpaste. It’s fantastic to take camping for all the reasons I mentioned plus washing the dishes and pans. I can remember reading all the text on the bottles and wondering “Who is this Dr. Bronner and why does he want me to Dilute! Dilute! Dilute!?”. I don’t get to The Raisin Rack as much as I’d like to any more, so over the years I have purchased the gallon bottles of Bronners soaps online. I’ve watched the cost go up over the years and I even tried some other less expensive Castile soaps that were not Bronners and was disappointed. I have been trying to reduce the plastic we use in the house and I have successfully made my own DIY Laundry Soap that everyone seems on board with using, I am still working out a good formula for liquid dish soap and we have tried toilet paper from Who Gives A Crap plus my wife Alissa gave the kids reusable produce bags, straws and eating utensils for Christmas.

Now it was time to attempt at making my own liquid Castile soap that was hopefully equal to Bronners at a fraction of the cost. I started down the rabbit hole of soap making information online. There are a LOT of people making their own soaps and writing about it. I narrowed my search to liquid soaps after finding that Castile soap was technically soap made from just Olive Oil. Bronners soaps use a combination of oils and I soon learned that each oil brings something unique but the consensus seemed to be that Olive Oil made a moisturizing soap and Coconut oil made a soap that lathered so a combination of the two seemed a good bet. I found a lot of sites and blogs that detailed other peoples recipes and attempts at making liquid soap. I worked out what sounded good for my first attempt and bookmarked the site everyone mentioned for calculating the amount of lye to use with oils Soap Calc. I procured what I needed from Bulk Apothecary which was Olive Oil Pomace, Coconut Oil and Potassium Hydroxide flakes or KOH. I opted for the pomace which is a lower grade and inexpensive olive oil because I was using this topically and not for cooking/eating. The pomace is roughly half the price of Extra Virgin Olive oil. I have not tried it for culinary but after reading up on it, I don’t think I’ll attempt it.

After selecting the ratio of oils to use for my first batch, I used the Soap Calc to get my recipe and the amount of lye (potassium hydroxide) to use. We have a slow cooker (Crock pot) I was using, a digital scale and stainless steel bowls and spoon. I added the oils to the pot and turned it to high.
While waiting for the coconut oil to melt and all the oils to warm up, I set myself up outside to work on the lye. It was suggested to do this outside and wear safety goggle and gloves. I just worked carefully outside. It was cold that day and we even had snow flurries and as I added the KOH flakes gradually to the water (never the other way around!) it was generating heat and due to the outside temperature it was steaming. Once all the KOH was dissolved in the water, I let it cool and brought it inside.
The oil in the pot was melted and ready for the lye to be added. I slowly added the lye to the oil and slowly stirred with a stainless steel spoon and then started mixing with an immersion blender.
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You’re supposed to mix with the immersion blender until it’s too thick and move to a spoon or spatula. It was easy to see the texture change as it mixed and eventually turned to something resembling mashed potatoes.
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At this stage you’re to keep cooking this blob for 3 hours, stirring every half hour until the blob turns turns to a translucent gel. After 3 hours though, I still had something in between the mashed potatoes and translucent gel . I had seen pictures of all the stages on various sites and kind of knew what I was looking for, but it was not there after 3+ hours.
So I want back and looked around online while my blob cooked. I read in places that this stage could take anywhere from 3 to 6 hours and what this stage was doing was cooking the lye so that the end result was not a harsh alkaline product that burned your skin. One of the tests to see if the soap was ready for the final dilution stage, was to take a small spoonful out and stir it up in a glass of hot water. I heated water up in the kettle to boiling, poured 8 ounces into a glass and stirred in a spoon of my blob. If the soap is ready it will dissolve to a somewhat clear state but if it dissolves and the water is cloudy or milky looking it is not ready. My tests were always cloudy looking, so I let it keep cooking while I stirred every 30 minutes. What formed on the top of the blob looked like the translucent gel I was looking for, but underneath that was a cloudy foam and as soon as I stirred it up, it lost the gel like consistency. By now it was night and I decided to turn the pot down to warm, leave the lid on it and see what it looked like in the morning.

By morning the blob still was not the translucent gel I was expecting so I turned the heat back up to high and stirred every 30 min again. Also, the smell of the soap was undetectable the day before but after cooking all night it was starting to have an aroma that Alissa did not care for. I again started looking around online for some help and read on a site that some batches of liquid soap may never dilute to completely clear and may be a little cloudy. I didn’t care if it was cloudy or clear, I just wanted to ensure all the lye was cooked out. Many sites suggested ways to check the Ph of your soap to ensure it will not cause a chemical burn but these tests consisted of Ph strips or expensive meters. I did find one site that detailed a way to check the Ph with red cabbage. I was on board with this since I had red cabbage on hand. All I had to do was grind up some red cabbage leaves and a little water in a food processor, strain out and reserve the red liquid and then add a few drops of the liquid on to a small blob of my soap paste.

If the red cabbage juice turned green, the soap paste was too alkaline but if it turned blue it was ok to use. As you can see above, it was blue!
Now to take the paste and dilute in 10+ cups of water. I added the paste to a large ceramic coated pot Alissa uses for canning. This process was slow but I just occasionally stirred the pot until it was completely dissolved.

I had to add a few more cups of water I heated up in the kettle and break up the last remaining globs until it was fully dissolved. I’d guess that it was an additional 5 cups and may be due to how long I cooked the soap paste. I strained the now liquid soap to catch any pieces of blobs that were undissolved and poured the final product in an empty gallon Bronners bottle. I had enough to fill the gallon plus 3/4 of a 32 oz empty bottle which I topped off for a diluted and ready to use soap for the shower. By making this without any scent or essential oils I can add any essential oils to the 32 oz bottles I have for the shower or for general cleaning. For the shower bottle I added Tea Tree oil and Peppermint oil. I plan to get some grapefruit or lemon oil for the general cleaning soap.

So, I will include the recipe I used for this batch below as well as the cost. A gallon of Peppermint Bronners soap is $65.00 retail (plus shipping).

Olive Oil Pomace – 680 grams
Coconut Oil (76 degree) – 454 grams

Potassium Hydroxide or KOH (90%) – 258 grams dissolved into
Water – 431 grams

These ingredients (minus the water) cost approximately $11.45


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