Absolute Oils, CO2 Extracts, Essential Oils... Know Your Oils!
So as you know, oil is an essential part of soap. You use vegetable oils with your main mixture in order to give your soap certain properties, and you use plant and flower oils to add scent to your products. Now, up until this point, we have only discussed essential oils and fragrance oils for adding scent to your soaps. But the truth is that there are a few other oil options out there if what you want to do is make sure your soap smells great.
Let's talk about absolute oils, CO2 extracts, and essential oils.
Starting with something familiar, essential oils are oils taken from flowers and plants. Produced via steam distillation, it is more potent than any alcohol based fragrance oil and must be used with caution. There are two types of essential oils, conventional and organic. Conventional essential oils are produced in high quantity and are cheaper because of the way they are farmed. Organic essential oils, on the other hand are more expensive, are produced in smaller quantities, but are healthier, safer, and are 100% chemical free.
Now, most people use essential oils because they are great for soap. However, there are some oils that are even better. Absolute oils are an example. Also extracted from botanicals, absolute oils are made from flowers that are too delicate for steam distillation, meaning the heat will destroy them a little. They contain a very high concentration of fragrance, and are more expensive than essential oils because of the process of production.
To produce absolute oils, you first have to follow a method of solvent extraction or enfleurage.
Solvent extraction involves putting the botanicals in a drum with a solvent mixture, like hexane, benzene, or petroleum. This mixture absorbs the extracts in the botanicals, and a process of vacuum distillation removes the solvent, leaving behind a resin. (There is a downside to this method, and that is that the resin can have impurities in it, and these have been known to cause allergies.)
Enfleurage, on the other hand, involves putting the botanicals upon fats. The fragrance of the flowers will be absorbed by the fats. This is done over the course of several days, changing flowers everyday. Once the fat is saturated with fragrance, it is called a pomade.
Either the pomade or resin is then washed with alcohol in order to extract the aromatic compounds, then it is distilled to leave behind the absolute oil. Since no heat is used, no damage is done to the flowers, which supposedly yields a better oil. Some common absolute oils include jasmine, lavender, mimosa, oakmoss, and rose.
Carbon Dioxide Extracts
Regarded as better than both essential oils and absolute oils are CO2 extracts. These oils are extracted using carbon dioxide that has been put under pressure (about 33ºC) until it turns to liquid. The liquid CO2 acts as a solvent, which almost immediately extracts oils from the botanicals. After the right amount of time, the pressure is released and the CO2 becomes gas once again. What is left behind is the oil.
What makes CO2 extracts ideal is that there is no trace of the solvent, as is sometimes found in absolutes, and no part of the flower is damaged, as often happens in essential oils. Plus, it is closest in aroma to the natural herb. Because of this, it is the most expensive type of oil you can use for making soap or any other cosmetic product!
The type of oil you use for your soap is dependent on how high you want the quality of your soap to be. If you are using high quality materials, then CO2 extracts are the most ideal. However, both absolutes and essential oils should also work just fine. The best way to learn about ‘different soap making oils’ is through experimentation, actually trying out the different oils.
To store your oils, be sure to keep them in air-tight glass bottles that are stored in a cool, dark environment, only taken out when needed. If kept properly, they can last up to five years!