Storage of Oils
How should one store carrier and essential oils? It is important to know the correct storage method if you want to use oils to the last remaining drop.
There’s nothing worse than having to discard a half bottle of oil, so treat them well and they should provide years of use.
Three main factors affect the long term longevity of an essential oil:
Any one of these can alter the chemical composition and evaporation rate of an oil which will impact on the efficacy of the oil for use.
When oxygen enters into the bottle and reacts with a component of the oil, it is called oxidisation. This can affect the therapeutic property of the oil, or worse, may cause sensitisation which may be hazardous to one’s health. You can tell if an oil is oxidised by the aroma (helpful only when you are already familiar with the aroma), or if you have an adverse reaction such as redness or irritation (in which case, do not use the oil for anything other than cleaning or you will increase your likelihood of future sensitisation).
Keep the Bottle Full
Giving little ‘headspace’ for oxygen to enter. If you are constantly mixing blends of a few drops, try decanting part of a larger bottle of oil into a smaller bottle. This will lessen the time the large bottle is open to the air and may help in making the oil last longer – and remember to keep the cap on when blending!
Keep it Cool
Both essential oils and carrier/vegetable oils do not handle extreme or repeated changes in temperature well. This can affect the therapeutic properties as well as longevity of the oils. Citrus oils are most prone and should be kept in the fridge where possible (or around 5-10 degrees), and vegetable oils can benefit from this storage during the summer months.
You will find some oils such as Rose, Peppermint and Jojoba will crystallise (or winterise) with the cold temperature. This is fine – they just need to be warmed up before use. You can either warm them up in your hand or stand for a few hours at ambient temperature before use (or 12 hours for carrier oil) and they will return to normal. In short, do your best to keep them away from any heat source (cars, windows or heating appliances).
Use Glass Bottles
Glass amber bottles are used widely for oils storage and for a good reason. Amber bottles are very effective at filtering out UV light, and other more interesting colours have become popular such as violet, green and blue. Regardless of the colour of the bottle, never leave your oils in the light. This will degrade them very quickly. It is also important never use plastic bottles for 100% essential oils, as it will dissolve the plastic, but carrier oils blended with essential oils are ok, as they are diluted.
We recommend oils to be stored in a dedicated aromatherapy wooden box - most importantly out of the reach of children and pets - as it will keep your oils safely in one place and will help to keep out heat and light.
How Long is the Shelf Life of an Oil?
This is the million dollar question, and is very hard to predict. Once you have purchased your oil, and endeavoured to keep it in optimum storage conditions, how long should you expect the precious contents stay usable? Generally speaking, the shelf life of an oil will depend on two things - the oil components and how old the oil is when you purchased it.
The chemical composition of oils is made from differing levels of components which oxidise or evaporate at different rates. Oils high in monoterpenes or oxides have the shortest life of around 1-2 years. Oils high in phenols can last up to 3 years, and oils high in ketones, monoterpenols and/or esters have a shelf life of 4-5 years. The longest lasting oil of up to 6 years contain sesquiterpenes and sesquiterpenols (phew!). Some oils age nicely like fine wine – and get more intense with age (like Rose, Sandalwood and Cedarwood).
Ideally buy your oils from a reputable store – known for high quality oils and who have a regular turnover. This ensures your oil will be the freshest it can be prior to purchase.
“It is hard to predict the shelf life of an oil because of packaging, storage, and shipping practices differ and you never know how old the oil is when it reached your cupboard. Your nose is the best indicator of the freshness of an oil.”
- “Making Aromatherapy Creams and Lotions” by Donna Maria