Investment Protection - Caring for Essential Oils

by Geoff Lyth

How long do essential oils keep before they lose their healing qualities?

That’s a very good question, and one that crops up a lot on our Helpdesk. Unfortunately, like so many questions in life it’s not as straightforward to answer as you might think . . .

Having invested hard-earned money in your essential oils, it certainly makes sense to look after them properly to ensure their therapeutic properties are not weakened or lost unnecessarily. Following a few simple guidelines will help to keep your oils in prime condition without any real effort or hassle on your part. Here are the facts.

First, the bad news

Despite what you may have been told or read in books, the so-called ’shelf life’ of essential oils is extremely difficult to predict once they are taken out of storage and put to use. There is no fixed length of time after you have bought them that your essential oils will keep before they begin to deteriorate and eventually become unusable.

With all natural products, it can be extremely difficult to predict with any kind of certainty how long they will keep because there are too many variables. Essential oils are not the same as simple commodities such as milk or bread which follow a predictable and rapid path toward spoiling over a known period of time.

Chain reaction

The shelf life of an essential oil is governed by its chemical stability, and anything that interferes with this stability will cause the oil to start the slow, but inexorable process of deterioration known as oxidation. And once this process has begun, there is no way to reverse or stop it; it is inescapable and inevitable.

Heat, sunlight and air can all have a detrimental effect on the chemistry of all the oils that are used in aromatherapy, and this also includes carrier oils and mixtures of both such as massage oil blends. In addition, the complex and varying chemistry of natural essential oils means that the rate of deterioration will be different for every individual botanical species of oil, even when kept under ideal conditions.

This means that some oils will last far beyond what many books report, whilst others may deteriorate much earlier than they claim. Either way, it is the combination of heat, air, the chemistry of the oil and the way they are stored that will ultimately dictate how long your oils remain in good condition. I did say it was not straightforward!

Now the good news

Despite all of this, the easiest way to extend the life of your essential oils is to simply store them away properly after using them. Essential oils do not like extreme or repeated changes in temperature, and ideally they should be stored in a cool dark place away from direct sunlight and other sources of variation in temperature.

Providing the oils were fresh when you purchased them from your supplier, this is by far the best way to keep them in good condition. This one simple tip could almost double the life of your essential oils.

Never leave essential oils in a place where the sun will shine directly on them such as on a window shelf in the bathroom, for example. Over a period of weeks this will dramatically speed up the natural process of deterioration due to them continually heating up and cooling down. Leaving your oils out in the sun like this can halve their life expectancy.

Stay cool

To avoid this type of temperature variation you may want to store your most expensive essential oils and absolutes in the refrigerator providing you have some space. Avoid placing them too near the freezer section and don’t have the refrigerator setting too cold; somewhere around 5 - 10 degrees Celsius should be fine.

You will find that Rose Otto and most absolutes will solidify at this cooler temperature, so you will need to allow them to warm up for a while in advance of using them. The ambient temperature of a room is usually enough to dissolve the natural waxes in Rose Otto, and if not, holding the bottle produces just enough warmth to liquefy the oil again.

One final point regarding storage of essential oils; because they are quite volatile, essential oils will evaporate fairly quickly so be sure to always replace the cap tightly when you have finished using them. You don’t want your precious oils evaporating upwards towards the heavens!

Buyer beware

It almost (but not quite!) goes without saying these basic guidelines assume that the products are fresh when you originally purchase them. Bear in mind that many oils can originate on the other side of the world and may have already taken 3 months to reach a distributor. Such oils may well have passed through the hands of several traders before finally arriving at your suppliers premises. The storage conditions used by everyone in the supply chain will have a major influence upon the condition of the oil before you have even purchased it.

Specialist aromatherapy suppliers should have quite regular deliveries of oils, so this should not (in theory) be a problem. However, if you usually buy your oils from retail outlets be sure to avoid bottles that are displayed on shelves under hot lighting or in direct sunlight. One final telling sign to watch out for is products on shelves that have accumulated a visible layer of dust!

Choose your source of supply carefully and then take good care of your oils. In turn, they will serve you faithfully and bring you the results that you deserve.