Over the years I have bought lots of essential oils, some better than others, and it can still feel a bit hit and miss with quality so I thought it might be useful to explain what I look for when I’m purchasing them so you can feel more confident in purchasing your own good quality essential oil products.
If you want to use your oils for aromatherapy purposes you will be looking for oils that are 100% pure, natural and authentic. This means they’re not adulterated with another oil or substance, that they don’t contain anything synthetic and they are in as full and complete a state as possible after the extraction process.
Regardless of your brand preferences, there are a few key things to look for. I look for labeling that clearly shows:
- Botanical name
- Part of the plant used to make the oil
- Country of origin
- Extraction method
The botanical name of an essential oil is really important. I promise it’s not just me showing off my Latin vocabulary. These names are often in italics. Sure the common name for is a good start, but there are lots of varieties of plants and they have different chemical compositions, and therefore different therapeutic actions.
Take German Chamomile and Roman Chamomile for example. Both are both from the Asteraceae family, but they are chemically different. They also have different therapeutic actions, and they smell different too.
In general terms, Roman chamomile is great for use in PMT/mood management and has anti-inflammatory properties but is sometimes a skin sensitiser. German Chamomile has greater anti-inflammatory properties, especially for skin care and is not known as a skin sensitizer.
If your oil bottle just says ‘Chamomile’, how do you know it will have the effect that you’re after?
(Handy hint – German Chamomile is usually blue in colour)
The part of the plant used to make the oil can be very important. For example cinnamon oil can be from the bark or from the leaf. Cinnamon bark oil has a high cinnamic aldehyde content, which is a skin irritant. Cinnamon leaf oil doesn’t have the high cinnamic aldehyde content, but doesn’t smell as ‘full’ as the bark oil.
When I’m making a massage oil blend I prefer to use the leaf oil. (You could use cinnamon bark on your skin, but it should be strongly diluted, and I wouldn’t recommend it for kids or anyone with any history of skin sensitivity)
The bitter orange tree produces neroli oil, petitgrain oil and the bitter orange oil. One tree, three oils. They’re all citrus aurantium var. amara but the part of the plant used to make these is what differentiates them.
Country of origin is important because growing conditions can vary so much, and the chemical composition of plants can be markedly different from country to country.
Basil is grown in many countries, but the basil sourced from Comoro Islands has a high level of the constituent methyl chavicol, which is a skin irritant. Better to use the basil sourced from France, which has a much lower level of methyl chavicol and is therefore more suitable for aromatherapy uses.
(Handy hint – even Basil from France can be a skin irritant, avoid use during pregnancy too)
Extraction methods also have an impact on the chemical composition of oils, and their therapeutic action.
Extraction methods most commonly used are:
- Cold pressing
- Distillation (including fractional distillation)
- CO2 extraction
- Solvent extraction
- Enfleurage
Cold pressing is used to obtain citrus essential oils and involves manually extracting the oil from the fruit peel, with no application of heat or chemicals. The oils are usually separated from other parts of the fruit by centrifugal force.
Distillation is a more complex process that involves the application of heat to the raw plant matter.
I’ll keep it simple (because I didn’t go past year 10 science with Mr Board) but steam or water distillation helps release the oil molecules from the plant matter and when the steam vapor cools and condenses, the oil molecules are also liberated and are referred to as ‘distillate’.
In the case of Ylang Ylang oil, this is often collected by fractional distillation. This is like normal distillation but the distillate is collected in batches. Sometimes these batches are mixed back together, and sometimes they are sold separately (they should be labeled as ‘extra’, No. 1, No. 2 or No. 3 to identify them properly)
CO2 extraction is well outside the realms of my year 10 science knowledge, however what I do know is that it uses very low heat levels to obtain the essential oils, the CO2 is inert so it has no chemical reactions with the essential oils, it is quick, and there is no solvent residue that remains after the process is complete.
The only catch is that it requires very specialized equipment, so if you see an oil that is CO2 extracted it will be more expensive than the same oil obtained via other extraction methods.
Solvent extraction is a gentler process than distillation, but still has a distillation component. This process produces oils known as ‘absolutes’.
The plant matter has the solvent passed through it under pressure, and the aromatic compounds are released. Both the compounds and the solvent are then released into a distillation vessel. The distillation in this case is to recover the solvent and separate it from the aromatic compounds.
The compounds obtained from this process are called a ‘concrete’ (unless it’s a resin, then it’s called ‘resinoid’). The concrete is then warmed with some alcohol at a low temperature, where the essential oil will dissolve into the alcohol. The alcohol mix is chilled, then filtered, and the alcohol is removed by further distillation.
There is a small amount of solvent residue left in the absolute, however there are government regulations in Australia about the maximum amount allowable.
Enfleurage is a manual, time intensive process and these days it isn’t used often for obtaining essential oils (other than some jasmine or tuberose). Basically long sheets of glass are covered with a layer of highly purified and odourless fat or oil and then the glass sheets are stacked like shelves in a wooden frame.
Fresh flowers are gathered very early in the morning before the heat of the day releases their scent. The flowers are placed on the sheets of glass. Over the course of a day or two the original flowers are replaced with new, fresh flowers. Eventually the scent of the flowers is absorbed into the fat, and then this is ‘washed’ with alcohol (like solvent extraction of an absolute)
Other tips
Care of your oil collection
I look for amber glass packaging, with a good fitting lid. Essential oils are quite fragile and don’t last well if they’re exposed to light, heat or open air. If the packaging is clear, or plastic then I wouldn’t be buying the product.
Keeping your oils in a cool dark place will help them last longer, and make sure you’ve put the lid back on tightly so they don’t oxidise.
As a general rule, citrus oils tend to oxidise more quickly than other oils. If they still smell ok, they can still be used in a diffuser, but if they have oxidized the chances of skin reactions increase so steer clear of them in massage blends or other direct skin application.
Cost
The cost of essential oils are influenced by the type of extraction method used, the amount of raw material required to make the oil, availability of the raw material, importation costs, packaging, advertising costs etc and even things like wars, natural disasters and general climate change can have an impact. That said, you can’t always judge an oil by it’s price. Do your research and look for reputable suppliers.
Sustainability and ethics
Issues of environmental sustainability and ethics are important to me too. Essential oils and their raw materials are sourced from all over the world so it’s important to know where your oils come from. I don’t want my oils produced using child labour, or by exploiting locals, or to be the cause of forest destruction. Reputable suppliers should be able to tell you where their oils come from, what sustainability policies they have, and should be able to explain their business model.
Soooooo, I hope you’ve found this post useful, and I hope it assists you in your search for good quality essential oils!
Take care.
x Zoe
References
The Complete Guide to Aromatherapy – Salvatore Battaglia
Published by Perfect Potion (Aust) Pty Ltd 1995
The Encyclopedia of Essential Oils – Julia Lawless
Published by Thorsons in 1992
