Soap making oils!

Why are certain oils not ideal for soap making? Have you ever wondered why soapers choose the oils that they do? How do we create our formulas?

First, the best point to remember of all is this: just because an oil is good in a lotion or leave-on product, does not make it a good candidate for converting it into soap. In large enough quantities, some saponified (soaped) oils can feel like taking a shower with lotion - no lather, greasy after feel! Some can go rancid too quickly (and who wants a rancid soap??). Some are just plain too expensive for use in a wash-off product. Others have components that the lye does not react with and therefore it does not saponify (turn into soap via a lye reaction) at all. Mineral oil is one such example. Jojoba oil is a close second in that category as it does saponify, but only a small part of it does - making it unsuitable for use in soap, except in minute quantities (it is also generally too expensive for many to put into a wash-off product).

Our soaping formula in action! Testing an essential oil blend out - rough life!

Without getting too in-depth about my formula, I will say that I (along with most other soapers) am always looking for that balance of cleansing, bubbles, lather with conditioning, moisturizing, and long-lasting bars. Bars that are too conditioning, with too much oil left behind can leave you feeling like you didn't get completely clean, and it can also mean little-to-no lather. Bars with too much lather and a very low superfat (superfat = a calculated excess of soaping oils that are left over in the bar and do not turn into soap) can make for a very drying soap that strips the skin. Balance is key.

Soap hardness and durability are another factor. We are always looking to create a harder, longer-lasting soap. Handmade soap cannot sit in water for any length of time and it should be allowed to dry completely between uses. We cure our soaps for 6 weeks in order to help produce a hard bar. Shea butter and coconut oil also helps achieve the same goal. Over a long enough period of time, olive oil also produces a very hard bar. We have started to include sodium lactate as well - this is a naturally derived salt from fermented corn or sugar beets, often used in the dairy industry (yogurt!).

Without getting too technical, the fatty acids included in every oil and butter we use are analyzed for the properties it will bring to the final soap. This is why we choose some oils and butters over others. Shea butter, for example, has a high level of unsaponifiables (components that will not turn into soap) which means that as a soap making ingredient, it is highly moisturizing. It is a butter with one of the highest levels of unsaponifiables, more so than cocoa butter, mango butter, avocado and kokum. It is also saponifiable enough to create an actual bar of soap instead of an oily mess, unlike high levels of jojoba oil. You could say that it's in the "sweet spot" for soap making! It also contains a healthy dose of stearic acid as part of its fatty acid profile - which makes for a very hard soap with stable, moisturizing lather. Is shea expensive? Yes. It is by far the most expensive soaping fat that we use. And we use a good chunk of it to boot (well over 20% of our soaping formula).



A bar of soap gone rancid. This one came from another soapmaker and contained soybean oil. It lived in my bathroom drawer for less than a year before I noticed the brown/oily spots. 
What about rancidity? Is this an issue? There are many soaping oils that have a tendency to go rancid rather quickly: grapeseed oil, soybean oil, peanut oil, cottonseed oil, rapeseed (canola) oil, sunflower oil and I'm sure some others that I'm leaving out. Some of these are very cheap to soap with, which makes them popular to use. If not protected with vitamin E or rosemary oil extract, I'd expect to try to use soaps with high amounts of these ingredients quickly (within 3-6 months) before the dreaded orange/brown oily spots occur (which means the bar turns rancid). Rancidity will make soap greasy, soft, and start to smell bad. It's a shame since soap generally is supposed to get better as it ages! Some of my favorite bars are ones I've hoarded for a year or more to use.

One final word. Any soaping formula is subjective. There are many different types of soaps out there, many different formulas (we use three here at OHTC!), and everyone feels soap differently. What might be "just right" for a mechanic's greasy hands is likely far too drying for my winter skin! And while many folks enjoy shea butter in their soaps, not everyone will. There's also something to be said for additives and essential oils when it comes to what they bring to soaps. Honey, milks, colloidal oatmeal, silk, clay, and even essential oils can all alter the skin feel of the final soap. We use these to our advantage here - it's not all about the scent or the color that these ingredients can give. It is, however, a happy side benefit!

I hope that this has helped you to understand the limitations of soap making and the reasons why we soap makers love the oils and butters that we do!