Hand-made Soap: What does saponification mean?

Saponification is a process

Do you use lye-based products to clear clogged drains? Do you remember references from days gone by that lye soap is scary stuff?

Pure Castile Soap
Pure Castile Soap

This is the reason soap-makers use the term “saponification” for our natural, hand-made soaps. You can’t make soap without using lye. Most people think of lye as only a strong caustic chemical that can burn your skin, or worse. Actually, through the process of saponification and curing, the lye disappears and you’re left with a beautiful bar of soap.

Lye is in all soaps, commericial and hand-made. “Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution. Fats and oils are composed of triglycerides; three molecules of fatty acids are attached to a single molecule of glycerol. The alkaline solution, which is often called lye, brings about a chemical reaction known as saponification. In saponification, the fats are first hydrolyzed into free fatty acids, which then combine with the alkali to form crude soap. Glycerol (glycerine) is liberated and is either left in or washed out and recovered as a useful byproduct, depending on the process employed.” Wikipedia (My hand-made soap retains the natural glycerine, which is a skin softening ingredient removed from commercial soaps and used in other products.)

After dissolving the lye in water, both the lye solution and the oils are separately brought to the correct temperature, then mixed until the “trace” stage. The soap is poured into moulds, kept warm and left to continue saponification for a day or two, or sometimes even three days. After this insulation period, the soap is firm enough to be removed from the mould and cut into bars. It is now safe to use, since saponification is in essence complete. However, cold-process soaps like my castile soap are cured and hardened on a drying rack for 2–6 weeks before being offered for sale. During this cure period, trace amounts of residual lye are consumed by saponification and excess water evaporates.

The end result? A beautiful, long-lasting bar of natural, moisturizing and skin softening soap — with none of the nasties found in the commercial/industrial stuff. And one last note: Many soaps sold as “Castile” are not true castile soap. The real thing is made only with “saponified” olive oil, no other oils. And one last hint for parents: plain old cold-pressed, virgin olive oil is the best thing for diaper rash! You’re welcome!

NOTE: I retired and no longer have a shop, but I still make this simple soap for my family and myself. August 2020: I finally posted the recipe & directions for making plain castile soap here.

21 Replies to “Hand-made Soap: What does saponification mean?”

  1. So, where can I find this recipe for 100% olive oil soap?

    1. As noted at the end of the article, I’ve closed my shop. If you send me an e-mail (jane@smallbones.ca), I’ll send you my recipe, though.

    2. I’ve now posted the recipe & directions for plain castile soap: https://www.smallbones.ca/janes-castile-soap/

  2. I think the soap making world needs to understand something, organic soap versus non-organic. Both are cold processed and handmade but using organic oils versus non organic oils is a big waste of money! All oils, organic or not saponify, literally their molecular structure is changed. There is absolutely no benefit to starting with organic oils. When the saponification process is complete, you’re left with a completely different compound…soap! There is no transference of pesticides, herbicides etc, because of the saponification process. Pesticides and herbicides etc, do not “live” through saponification. People have been sold a bill-of-goods for years, it’s time someone told soapmakers and natural soap buyers the truth. There is no difference between soap made with organic oils and soap made with non-organic oils. Organic soaps just cost more but offer NO additional benefit!

    1. I’m sure you’re correct, Bill. I use regular olive oil for my Castile soaps, but I use organic oils in my Hemp Shampoo Bar mainly because the organic, virgin palm oil I use is from Juka’s Organic Co., which partners with women from small villages in West African, where the trees are native and the oil has been produced for centuries. These women stand against deforestation and harming wildlife. Hemp oil is almost always organic because it doesn’t need pesticides/herbicides. (I also don’t charge an arm and a leg for this soap just because it’s made mainly with organic oils.)

    2. Hi Bill,
      Isn’t organic farming better for the earth, what with there being no chemicals to leech into the earth etc? I think that’s a benefit.

  3. […] Source: http://www.smallbones.ca/blog/hand-made-soap-what-does-saponification-mean […]

  4. I am sure the fathers would love your tip for nappy rash too, no?

    Thank you for the great information on soaps! I am just starting my research into making natural products- so it was brilliant to read your well- explored info!

    1. You’re absolutely correct, Emma! I’ll add “fathers” right away. I’m surprised that I said that as my son is one of the best parents I know. Thanks for pointing out my booboo.

  5. I am making homemade laundry detergent, loving it, (great for the front loader as it got all gummed up and hubby had to fix it long story but I had no desire to buy another washer when mine was only 3 yrs old.) I use
    baking soda boraz, oxy clean (not brand) aram and hammer washig crystals, and I can throw is some essential or scented oil) but my question is what kind of soap bar that I would grate and can I use, the recipe calls for fells nappa or zote. I cannot find these, and I have used sunlight bar soap I found in the detergent isle of walmart. I have hard water, I would like to use something with a vanilla smell or almond etc. or ivory bar soap, are the soaps in the toiletry isles fatty or will be oily on the clothes? Are they saponated? I just made my second batch with the second bar of the 2 pack of sunlight soap. So I have time till I make the next batch would love to know what is the best bar soap to use with this recipie Thanking you in advance, lisa

    1. Hi Lisa:

      I use my own castile soap (it’s 100% natural; I wouldn’t use any store-bought soap) which you can find right here on my website: http://www.smallbones.ca/product-category/smallbonessoap/.

      This is the recipe I use: http://whynotsew.blogspot.ca/2010/08/how-to-make-homemade-laundry-detergent.html
      One bar of soap makes a lot of liquid laundry soap! I have hard water as well. This soap doesn’t suds up much, but it cleans the clothes!

      1. Teresa Peralta says: Reply

        I’m curious that you say you would only use your own castile soap because it’s 100% natural, which seems to imply there are no natural store-bought products available. There are several, in fact, that are. No disregard to your method, ethics and wonderful products (per feedback comments). And your pricing is similar to these products available locally. Just seems a bit misleading to dismiss all store bought products as impure and ‘nasty’ when so many stores are making a point of carrying well-made products such as yours.

        1. Thanks for your comment and interest in things natural, Teresa. More and more people are joining people like you and that can only make the world a better place!

          I’m glad that there are several good soaps available where you live. In my area there aren’t, except those made and available only from other independent soap-makers. Have you checked all ingredients in the ones you reference?

          Dr. Bronner’s is very popular, I know, but it’s available in only one specialty store in my greater area (and costs more). Some of their products also contain ingredients that aren’t natural according to the EWG website. I’m happy if there are many more – I’m not trying to push mine only. It’s true that I wouldn’t use any store-bought Castile soap for my laundry as I know that it’s natural, sustainable, and contains only olive oil.

    2. Use the ” laundry ball ” ! View at http://www.smartkleancanada.com . No soap at all!

      1. Mark, I prefer to use no plastic when possible, and I’m very happy with my own frugal washing powder. I have very hard water, so I add baking soda and no-name oxygen cleaner directly to my laundry soap recipe. Two tablespoons per load and for about $40CAD, I have lovely clean laundry for at least a year! I read about the SmartKlean ball & if I used it I’d have to add those things to it so it would save me no time and I’d be using a plastic ball.

        1. Hi Jane, have you tried soap nuts for your laundry cleaning? My son introduced them to me. They work wonderfully for all my laundry as well as for my son’s family. Just putting it out there.

          1. Hi Jane! Yes, I’ve tried them & they were okay, but it’s less expensive and easy for me to make my own detergent. I encourage others to try them, though. Thank-you!

  6. you say that (the real thing is made only with ” saponified” olive oil, no other oils. what about saponified virgin coconut oil?

    1. I was speaking only of castile soap. Castile is a region in Spain where they grow olives, so Castile soap is made with olive oil. Virgin coconut oil is great stuff, too! I use it in my Hemp Oil Soap & Shampoo Bar.

      1. Hi there!
        Wonderful article!

        May I ask, is there a difference between the functionality of saponified oil (Soap form) and unsaponified oil?

        For example, coconut oil has lauric capric and caprylic acid that provides anti-microbial, anti-fungal and anti-viral properties. Once saponification with lye occurs, does the soap attain the same mentioned properties?

        Thanks a lot! Very appreciate it.

        1. I’ve never found any scientific evidence either way, Bob. Just from general experience, I’d say that at least some of the properties of various oils are retained or all soap would be the same presumably.

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