From cosmetics to cooking, massage to health supplements, oils are an essential part of everyday life. But how much do you really know about them? Their origins, methods of extraction and processing techniques can be confusing and leave you unsure of the quality of the oil you are using. When selecting your oils, the quality level should suit your intended use of the product.
Oils for CosmeticsOil is a broad term for 3 types of compounds, all of which are used in cosmetics due to their emollient and moisturising properties.
1. Oils (including butters and waxes) such as Sweet Almond, Shea Nut Butter and Jojoba are organic compounds containing carbon, hydrogen and oxygen. The carbon and hydrogen combinations create a fatty acid that is linked in threes by glycerine to for a triglyceride. The oil's fatty acid profile determines its unique characteristics and specialty skin benefits.
2. Esters are chemical compounds that contain alcohols and acids. They usually have a scent and are found naturally in essential oils. For example Linalyl acetate found in Lavender oil and Geranyl acetate found in Geranium oil.
3. Waxes have the highest molecular weight and are typically solid at room temperature. Often made from chemical combinations of fatty acids, fatty alcohols and saturated hydrocarbons, they can be derived from plant, animal and petroleum. A plant-derived example is carnauba wax, an animal is Beeswax and a petroleum is paraffin wax.
Each of these 3 groups occur in nature, but they are also produced synthetically. While natural oils offer important nutrient benefits, synthetic oils can offer stability. Choosing between them comes down to the compatibility with your application for the product. Here at Sage we are all about natural so in this blog we are focusing on natural carrier oils.
Natural carrier oilsDerived from seeds, nuts, pulp and fruits, natural carrier oils are non-volatile and suitable to be applied neat to the skin. Common uses include therapeutic massage or as ingredients in natural cosmetics such as cream emulsions or balms.
Varying plant species, origins and extraction methods create distinctive characteristics within each oil and influence their performance on the skin. Sunflower oil, for example, is fast penetrating and offers skin softening properties, whereas Castor oil is highly protective and thicker in consistency.
Extractions methodsCommon methods of extracting natural carrier oils:
1. Mechanical extraction, incorporates Cold Pressing and Expeller Pressing. Both utilise the same physical technique to extract the oil. However, the key difference is the variation in temperature throughout the extraction process.Cold Pressing employs a mechanical screw press to extract oil from plant material. There are no chemical substances used and a low temperature (max 50°C) is maintained throughout the whole process to ensure the delicate properties of the oil are preserved.Expeller Pressing also works with a mechanical press but the temperature is not capped. Thus, it may reach up to 85°C during the extraction, depending on the specific nut or seed being pressed. The level of heat is a direct result of the physical friction of the metal press. Both the heat and pressure force the oil from the plant material.
2. Solvent extraction utilises solvents such as hexane or heptane to dissolve the oil from the finely ground seed meal. Evaporation of the solvent occurs after extraction and leaves behind the final pure oil. Economical benefits of this method are seen in quicker production time and higher yields, plus solvents can also extract residual oil from plant matter that has already passed through expeller press.
Differences between Unrefined and RefinedUnrefined oils, also known as Virgin or Crude oil, remain closest to their natural state. They are high in beneficial nutrients and retain characteristic colour and odours. This grade of oil is typically filtered after extraction to remove residues and unnecessary particles, but no further treatment is undertaken.
Refined oils are processed further to remove excessive colour, odour and other impurities. Refining increases the stability of oil and encourages a longer shelf life.
Refined oils still retain key characteristics and cosmetic benefits and can appeal to manufacturers who require product consistency. They need oils with balanced and stable fatty acid profiles for their regular cosmetic production. Whereas, massage practitioners often seek unrefined oils to enhance the benefits of the oils the use for their treatments.
If you want to learn more about how to use Carrier Oils and make your own natural skincare products, why not join us at one of our upcoming workshops? We hope to see you at our studio soon!