Bad soap happens. To clarify, I'm not talking about ugly or misshapen soap, or fragrances that don't smell good. I'm talking about soap that is spoiling.
Soap gone bad will do one of two things:
When using foods in soap, we use fine purees that allows the natural pH of the soap to preserve the small molecules of food matter. No big chunks allowed!
To preserve oils, we may add ROE (Rosemary Oleoresin) to our oils before soapmaking to prevent oxidation, or we may add EDTA or citric acid during the soapmaking process, which helps prevent rancidity. Some soapmakers, and I am in this group, chose to reduce the amount of free oils available for spoilage in the soap.
These free oils are called "superfat". A percentage of oils intentionally left out of the lye calculation that prevents them from turning into soap. Superfat is what makes handcrafted soap better than your average supermarket soap.
So how do you tell if your soap oils are spoiling? Your soap may develop raised portions that are slimy and... well... gross, like in the picture above. [side note just in case you're curious: I was given this soap a few years ago for Christmas. I found it just this weekend when I was cleaning out my soap stash. It is a goats milk soap, so I suspect that the soapmaker uses a high superfat in addition to the natural fats in the milk. This left a lot of room for spoilage. Lesson: Don't be like me, use your soap in a timely manner.]
If the soap is covered in a white ash that is not orange or green mold looking, that is a natural occurrence in soap called soda ash. It is not spoilage! I just wanted to clarify that, because soda ash does sometimes show up on my soaps. The EucaMint Coconut Milk soap is a popular soap that shows this phenomenon. It's safe to use and won't hurt you. (I'll talk about it in a future post.)
In the picture below, you'll see that this soap has orange discoloration, most noticeably surrounding the heart design. Soapmakers call this DOS, or dreaded orange spots. This soap was an experimental recipe that I made in the beginning of this year using sunflower oil. Unfortunately, I did put this soap into the store, but a few months later noticed that my stock had started to turn dossy, so I removed this soap and all the soaps that used that recipe. (I've gone back to my policy that all new recipes need to pass the 9-12 month life cycle test.) These orange spots are a sign that the free oils in the soap have started to turn rancid. These soaps will also begin to smell "off" or unpleasant.
Are dossy soaps safe to use? Yes, if you're comfortable using it, go ahead (and do it quickly because DOS will get worse the longer it sits)... but I don't want you to. If you ever find an AMD Soap that has developed DOS, please contact me. I'll send you a replacement soap.
What can you do to prevent soap spoilage? Use soaps in a timely manner. Even though I test my recipes 9-12 months before I make changes, I suggest never keeping more soap than you can use in a year. And yes, you can shame me because I don't follow my own advice. We'll talk about that in another post... Store unused soaps in a cool dry place, such as a hallway closet or linen drawer. Bonus! Your linens will smell awesome! Don't store them in a bathroom. Also, don't store soaps in a plastic tote. Shoe boxes or other cardboard boxes work great if you need to keep them bundled together. Plastic totes or bags invite and trap moisture, making your soap unhappy.
Life is too short to use bad soap.
Stay Soapy, Friends!