What are Essential Oils?
What are Extracts?
There are several types of extracts.
- An infusion is made when the plant material is let to steep in water or oil for a period of time. A water-based infusion is made just like you'd make a cup of tea--boil the water and add the herbs to steep for anywhere from 5 to 30 minutes. With an oil infusion, the steeping time is much longer, from days to weeks.
- A tincture is an alcohol-based extract. The plant material is steeped in a solution of (usually) 50% alcohol. The plant material steeps for days to weeks to extract compounds from the plant.
- These are liquid extracts in glycerin.
You may see a few ingredients listed as essential oils, when in fact, they aren't truly essential oils. Take for instance vanilla. The "essence" of vanilla is difficult to extract via steam distillation, so it's typically extracted through steeping in alcohol (most commonly) or in oil. This is the traditional vanilla extract that you'd use in cooking. This is the least concentrated form of vanilla extract. But, for a more concentrated form of vanilla, there's vanilla oleoresin. (Sometimes you'll see it listed as essential oil.)
An oleoresin is created by taking an alcohol-based extract and evaporating out the alcohol. You're then left with a thick resinous material that's a more concentrated form of the aromatics that the plant provides. Two common oleoresins are vanilla and rosemary. Vanilla oleoresin is commonly used in personal care products as a scent. Rosemary oleoresin (also listed as rosemary extract) is used as an anti-oxidant in foods and personal care products, helping give oils a longer shelf life. (Do note that it is an anti-oxidant, not a preservative. It will help keep oils fresh but it does not stop bacterial growth.)
Finally, there are absolutes. This is the most potent and concentrated form of extracts. Absolutes are typically extracted with a solvent like hexane to create a waxy material called a concrete. The concrete is mixed with alcohol to further extract the aromatic compounds. Then, the alcohol is evaporated out and a highly concentrated oil known as an absolute is left behind. Sometimes people will mistakenly list an absolute or oleoresin as an essential oil, whereas they are technically not an essential oil. Plants that are typically extracted as absolutes instead of essential oils include vanilla, jasmine, tuberose, oak moss and mimosa. When it comes to roses, both steam-distilled essential oil and absolutes are made. There are actually absolutes of honey as well, that will extract the delicate fragrance notes from different types of honey.
There are some ingredients that you'll see listed as "extracts" on a product, when they're not really an extract.
- Japanese Honeysuckle Extract is not a true extract but a highly synthesized preservative.
- Grapefruit Seed Extract is not a true extract, but a quaternary ammonium compound that's also used as a preservative. (Not to be confused with grape seed extract, which is a totally different thing, extracted from grapes, not grapefruits. Grape seed extract is a true extract.)
Vegetable or Carrier oils are true oils, composed of lipids (fats). These include sunflower, jojoba, safflower, almond, olive, coconut. They are either solvent, or, preferrably, cold-pressed from the seeds, nuts, or fruit of certain plants. Some carrier oils sound like essential oils, when they are not. For instance rosehip seed oil is not an essential oil but a vegetable carrier oil. After the rose has blossomed and created a rose "hip", inside this hip are hundreds of tiny little seeds. These seeds are taken and pressed to create rosehip seed oil. It doesn't smell like roses, but has a nutty, seed-like aroma. Red raspberry seed oil is also commonly confused. It is pressed from the raspberry seeds and while it does have a mild raspberry aroma (somewhat like raspberry leaf tea) it is not an essential oil and is used for moisturizing properties, not for scent or aromatherapy.