Many soapmaking oils can be found in grocery store aisles, and after awhile it begins to beg the question — can you really use store bought oils in your soaps? While this may seem like an easy, convenient and inexpensive option, we did a little research to find out. What we found was sadly not surprising.
We tested 10 olive oils total, including our own Pure Olive Oil and Pomace Olive Oil. These Olive Oil were small sizes, purchased off of retail store shelves at a local grocery store and a chain grocery store (generally, 8 to 16 ounce sizes; the smallest each brand had to offer). Each recipe was comprised of 100% olive oil, made in 1 lb. batches, had no water discounting and used a 5% superfat. We soaped at the same temperature for all 10 batches and soaped all 10 batches over a 2 day period to ensure as close as the same temperature and humidity conditions as possible for gel phase and cure time. We tested store brands as well as private labels, and every kind of olive oil from ‘virgin’ to ‘extra virgin’ to ‘light’. All bottles listed “Olive Oil” as the only ingredient on their labels.
Here are the results of the tests after unmolding. As you can see, some of the tests did some interesting things. What’s more, all of the store-bought oils except one exhibited terrible DOS after only a month! DOS is a common soapmaking acronym and it stands for “Dreaded Orange Spots.” Old or unpure oils can go rancid in soap, producing the tiny orange spots that give DOS its name. They’re not harmful, but they don’t make for pretty (or good smelling) soap. This lead us to believe that while these olive oils appeared to be fresh and pure, there may have been extra additives or old oil stock in them that caused the soaps to go downhill so quickly. The most interesting example was a soap made with “light” virgin olive oil:
This had one of the most bizarre textures we have ever seen! The batter was extremely hot after pouring, and then developed a spongy, foamy texture. It also formed a thick layer of cake-y soda ash on top.
The same soap from the side. The heat caused some crazy expansion which bowed out the sides of the super-duper reinforced silicone mold.
The results of these tests speak for themselves. While you technically can make soap with small sized store-bought oils, you can see that the results can be unpredictable and in these tests, didn’t result in the highest quality soaps. In these tests, only the soaps made with Bramble Berry’s Pure and Pomace Olive Oils stood the test of time and did not behave poorly or develop DOS. If you are going to use store bought oils, always do a small test batch before doing a large batch. And if you do some test batches, I want to hear your results after a few months of curing time. I was extremely surprised by the poor showing. I have successfully (for years) used Sam’s Club, Costco, and Cash ‘n’ Carry bulk oils with success. I suspect these results from smaller grocery chains were because the lower down the chain the oils get, the more options there are for adulteration and excessive aging. After all, who knows how often a grocery store turns over its Olive Oil supply?
The soapmaking process involves many factors and variables that can cause things to go awry, and the best you can do is buy soapmaking oils from a reliable vendor who can verify their quality and purity.
Bonus: An All Olive Oil recipe
Olive oil is one of the few oils you can use up to 100% of in your soaping recipes. It produces a lush, nourishing bar of soap. Soap made with 100% olive oil is also known as Castile soap, which is named after the region in Spain where the soap first originated. Castile soap takes much longer to harden up than traditional cold process recipes, so be patient when making Castile soap. It may take up to double the wait time before you can unmold it! Bramble Berry carries several Castile soap products, including Natural Castile Liquid Soap Base and Castile Rebatch. If you’d like to try your hand at making an olive oil soap, the Buttermilk Baby Bastille Bar is a great starting point. Although it also contains coconut milk in addition to olive oil, it’s a great introduction to high olive oil content recipes.