Hands down…the seminar I enjoyed most at the 2011 Handcrafted Soapmakers Seminar was The Secret Life of Soap by Kevin Dunn.
Kevin Dunn is the Elliott Professor of Chemistry at Hampden-Sydney College. Professor Dunn has undertaken a series of research projects on the chemistry of handcrafted soap.
It was refreshing and exhilarating to hear a seminar on soap making that involved deeper explanations of the chemistry of soap making that was not only entertaining but easy to understand!
One of my favorite things about Professor Dunn is his ability to make us non-chemist types understand the findings from his research. In his seminar he used an entertaining story of cheerleaders and nerds (which I thought was brilliant) to compare the reaction of oils and water. You didn’t have to have a chemistry background or even the knowledge of chemistry jargon to follow along.
Some of the interesting topics he discussed:
Soda ash (commonly referred to as ash) is a pesky little problem that just about every soap maker has encountered at one time or another. You put your soap to bed…wake up in the morning and there is a powdery layer of “something” blanketing the surface of your soap.
What is that “something?” Professor Dunn explained to us that it is sodium carbonate. Sodium carbonate forms where lye meets air. We know it is sodium carbonate if it is soluble in water (you can rinse it off) and it completely covers the surface of the soap that is exposed to air. If you have white dots or streaks, especially below the surface of your soap, these are usually something else and not ash.
How do we prevent it?
Cover your soaps with wax paper or plastic wrap to keep the air from “touching” your soap surface as it saponifies.
Do not uncover or unmold your soap until it is “tongue neutral.” This is especially important to remember when you are doing un-gelled soap. In my experience un-gelled soap takes longer to complete the process of saponification than gelled soap and can sometimes remain “zappy” 12-24 hours (sometimes more) longer than the same recipe when gelled. Once saponification if complete (no zap) you are usually safe from the ash monster.
If we get it, how do we remove it?
Since ash is just an aesthetic issue we can remove it from the bar of soap to “fix” the problem. You can do this by rinsing off with water either by putting it under running water or by rubbing it off with a cloth. If my soap bars have a flat enough surface I like using a vegetable peeler to remove the ashy surface.
Another exciting thing we learned? Cetyl alcohol is a great substitute for jojoba oil. Jojoba prices have been sky rocketing lately and it’s hard to even find jojoba from some of our favorite suppliers. He sought out a replacement at the urging from Mike from Columbus Foods. His result was cetyl alcohol (+ other fatty alcohols and waxes).
He also shared that during his research (actually making soap with cetyl alcohol) he found that soap made with cetyl alcohol helped to sustain the soap’s lather. Of course I immediately thought of a shaving soap! So this is definitely on my list of things to try. (If you want to try it out…start with 5% and go from there. Cetyl alcohol does not have a sap value so add it as you do beeswax and other general additives.)
What is cetyl alcohol?
Cetyl alcohol is a saturated, fatty alcohol with similar properties to those of stearic acid. Even though it’s called an alcohol…its physical characteristics resemble that of a wax. Cetyl alcohol is generally derived from petroleum or vegetable oils (coconut or palm). Your supplier should be able to tell you if their cetyl alcohol is derived from petroleum or vegetable oils. Since cetyl alcohol is saturated…it has a stable shelf life (something we consider when choosing ingredients for making soap).
He covered many more topics in the seminar. If you missed it…don’t fret. You can always get his book Scientific Soapmaking. I ordered this book when it first came out and it has proved to be a wonderful resource providing answers to my soap making chemistry questions. It also gets me to think outside of the traditional soap making box. You can find more information about Kevin Dunn and his book at www.scientificsoapmaking.com.
I’m not sure why Kevin Dunn has chosen the topic of handcrafted soap to focus a bit of his research and time on. I wonder if it has anything to do with the swarm of women he had flocking around him at the conference! 🙂 Whatever the reason…I’m so happy he has done the research and generously shared the results with the soaping community.
And yep…I got to give him one of my shirts I have printed! Thanks for a wonderful seminar,
Amanda…I am also curious about using the cetyl; alcohol in my soaps. Would I add it at trace or in the lye water?
Hi Ingrid! You would add it to your oils and melt with them.
Hi Amanda! I just just talking with Mike from Columbus Foods about my geeky preoccupation with all things chemistry, and he recommended I get Kevin Dunn’s book- I googled it, and got your blog instead! Thank you so much for posting about Kevin’s findings on soap ash. I’ve looked for an authoritative answer to the “what’s that white stuff” question for a while, and this was just what I needed. Can’t wait to read more of your posts!
Hi Erin! Kevin Dunn rocks! The soapmaking community is very fortunate to have his support and curiosity. Hi book, Scientific Soapmaking, is excellent.