Essential Oil Quality

Essential Oil Quality – different grades, where to use them, how to identify them

One of the common questions that therapists raise concerns the quality of essential oils.  Most schools teach that only “good quality essential oils” should be used.  Very few schools attempt to clarify what is meant by the statement, although by its very nature there is an implication that “bad” oils exist.  This is an over simplification and is often related to the fact that schools are attached to a particular brand name, perhaps one that they promote.

So let’s start at the beginning.  We must remember that essential oils are a product of nature and that like wines, the aroma of the plant varies from year to year, from field to field.  The vigour of the plant, its habit, its growth is also dictated to by the vagaries of soil, agriculture, horticulture and the seasons.  The production of essential oils as an agricultural practice is like any other a chancy business.  Nature is variable not exact.  

This, then, is the context of the answer to the question.  People want natural, but natural is variable, not consistent or standard.

The first question a therapist should ask is not “what is the quality?” but rather “what do I want to use the essential oil for?”  In any practice there might be a variety of purposes

healing or medicine

psychotherapeutic or body work

environmental fragrancing for different purposes


perfuming cosmetics or perhaps as active ingredients in cosmetics

The list goes on.  It must be immediately apparent that it may not be necessary to use the same “quality” for each of the applications.  

Such matters are raised by looking at the brands retailed to the consuming public.  No brand is ever sold as poor quality yet prices vary.  The supply is not limitless.  Few if any retail brands would venture into the highest quality hand cut, high altitude lavender market.  There just isn’t enough to go around!  The worst thing any brand can do is try to sell something they can’t actually get so retail brands have to rely heavily upon materials that are regularly available, not the speciality lines sometimes desired by aromatherapists or by couturier perfumers.

We could divide essential oils into three loose categories

Synthetic or semi-synthetic.  These would mimic the fragrance of the plant using aroma chemicals either manufactured or processed from original plant material.  Sometimes these are called nature identical which is a euphemism for artificial.  They are not essential oils but are poor mimics.  To sell them as essential oils without clarification would, in my opinion, be fraudulent.  Their main use, by the way, is in the flavourings business as well as perfumery.

Industrial.  This category covers a variety of materials – the good, the bad and the ugly.  The essence of the category is about blending and standardisation.  Very few essential oils are sold direct to primary users – most growers and co-operatives sell to large companies such as Adrian, Robertet and similar.  Such companies gather together a variety of crops from different places and blend them together to achieve a certain “quality”.  The end markets for such qualities often require a reproducable product and each season’s production may be adjusted to match last year’s and so on.  At one end of the market the product may be quite good, it may be a blend of lavender from a specific co-op.  At the other end an essential oil may be added to or constructed using natural components or chemicals drawn from essential oils that did not originate from that particular species or indeed a synthetic may be added to boost say a content in one component or another.  The destiny of these industrial essential oils is very wide – many markets are served and many retail brands of aromatherapy products are drawn from this sector because of reliability and generally consistent availability.

Pure and natural.  I have borrowed this term from European continental users.  It is not strictly a technical term used in the UK, as in the UK it is applied to virtually anything and everything and has become meaningless.  It is used here in the sense that like a fine wine the origin is from a single source and certainly without additions.  The category often includes categories like organically grown or wild crafted materials and it is this group of oils that is generally considered better for aromatherapy, especially for those practitioners that there is a life force.

Once we have these basic categories in mind, we can move on to consider the many processes that will affect the aroma or the smell of the oil – when it is harvested, how it is dried, how it is distilled.  It could for example be short term high pressure or it could be long time low pressure.  Many, many factors go to make up the “quality” of the essential oil.

When discussing quality, therapists may also be concerned about the type of plant that is grown.  We can use the ever popular lavender as an example.  There is lavender grown from seed (originally from the wild).  This is population lavender and it exhibits a very fine aroma.  In its natural state it has a variety of colours from pale blue to a dark mauve.  It is lavender in its natural state.  Such fine lavender is far from common.  The most commonly grown form of true lavender is clonal lavender.  A particular colour or plant with habit is chosen and a small cutting taken and grown on from year to year.  These days even one cell from a plant can be cultivated.  Some practitioners question this form because it does not demonstrate the life force they feel they require.  Others are quite content to use such material, perhaps basing their view upon chemical analysis.  Either way, the clone Maillette represents the majority of true lavender that is sold today.  Lastly there are the hybrid lavenders or lavendins.  Large volumes of this material are sold and undoubtedly it can easily be misrepresented as true lavender.

Where does analysis stand in all this?  Often companies promote the idea that their product has been analysed and therefore must be true etc.  I once heard Dr Brian Lawrence, the world’s leading authority on the analysis of essential oils, explain that falsification is extremely difficult to detect.  Usually in aromatherapy only limited analysis is undertaken, perhaps looking for the top ten marker chemicals, seeking out obvious adulterations.  This is a good thing especially for a cheap oil and it can give some sense of security.  Those companies who know their sources, however, may view analysis not as a test for adulteration but rather to see what the componency is.  As stated above it can be variable.  

Analysis is not therefore the arbiter of quality but a verification process.  How then to assess quality?  Well, the nose says it all.  As stated at the beginning you have to identify the purpose.  A pretty smell at a dinner party is not the same thing as trying to induce sleep.  Essential oils work at many levels, not least of which is the perception by the nose.  Odour molecules are communicant molecules.  If we remember that most of what we call taste is in fact smell – taste after all is only sweet to sour so every nuance of taste after that is odour perception – this should give us some idea about judgements on essential oils.  We need to look at its impact note, we need to look at the dry out smell.  We need really to think through the spectrum of the odour – how does it make me feel?  In particular we can feel its vibrancy.  These may seem strange terms in a world where we simply look at an analytical table, often over simplified.  Would you however buy your apple juice by its analysis, would you buy wine by its analysis?  I am sure you would not.  Rather you rely upon taste and your nose.  That may mean that you have to go to school to learn about odour profiles and to make large comparisons.

My advice is to look for that simple impact.  It is not a question of whether you like or dislike but whether it moves you.  What a great detector the nose is and sometimes the unmentioned, very minor elements play a great part in the odour profile.  David Williams long ago commented upon a sulphur containing trace constituent of grapefruit oil.  He pointed out that 10 mls, if evenly distributed about the world, would overwhelm the population of the earth with its smell.  Something to think about?

There can be huge fluctuations in price.  It is only a few years ago that patchouli, quite a common oil, could not be bought for love nor money.  Like wines, the best oils could always command a high price.  There is no need to cut price for the very best oils as they are always in demand.   As with wines, there are no bargains with the best.  Expect to see high prices for good quality oil but with experience you will soon be able to discern what is moderate, normal and evidently cheap.  There are always reasons for cheap prices and a few real bargains exist.  This is a huge subject and experience is the best tutor.

I hope this short article has pointed out that defining quality in essential oils is complex.  It depends upon its end use.  Quality may also be affected by the therapist.  Storage for example.  Essential oils, whilst long lasting, do change, they do react to oxygen so my advice is to buy little and often which brings us neatly to the subject of price.