Essential oils don’t last forever. In fact, they have distinct shelf lives that range dramatically from variety to variety, and even batch to batch! Certain oils, such as sandalwood and patchouli, last a very long time. Others, such as citrus oils, slide over the hill relatively quickly.
It’s not that pure essential oils go rancid; instead, they oxidize over time and lose their therapeutic value. How long your oils remain effective depends upon a multitude of factors, including:
- When and how the plants producing the oils were harvested;
- How and when the oil was distilled; and
- How carefully the oil was stored and packaged after distillation.
Storage and packaging can make a huge difference in your oils’ longevity. If a seller keeps his or her high-quality oils sealed in a cold room or nitrogen blanketed and refrigerated, those pristinely made and preserved oils are going to oxidize far, far later on down the road than oils kept in brightly lit, warm settings. In general, colored bottles are better containers for storing essential oils, as clear glass will allow light to oxidize the therapeutic compounds in the oils. If you’re storing large quantities of essential oils, downsize your bottle size as quantities diminish, to keep air from damaging the oils. Another tip: Do yourself a favor and note the date of purchase on the lid of each essential oil you buy.
Here’s a rough guide to essential oil shelf life (assuming they are kept sealed in dark, cool spaces):
1-2 Years: Neroli, Citrus, Lemongrass, Frankincense, Tea Tree, Pine, and Spruce Oils. These oils contain monoterpenes, particularly limonene, so are more apt to oxidize. Most citrus-peel essential oils consist of 90% or more monoterpenes and therefore have the briefest shelf lives. Other oils that are more than 80% monoterpene include Angelica Root, Cypress, and Frankincense, as well as Pine and Spruce.
2-3 Years: Most other essential oils.
4-8 Years: Vetiver, Patchouli, Sandalwood. Oils containing a significant percentage of sesquiterpenes and/or sesquiterpenols boast the longest shelf life. *N.B.: Although the aromatic quality of these oils may improve over time, their therapeutic quality can still diminish.*
For more information on storing your essential oils optimally, check out the web page “Lemon on the Rocks” by Robert Tisserand.
How can you tell if an essential oil has lost its therapeutic mojo? Three primary signs:
- The oil’s scent has changed
- The oil is cloudy (if a citrus oil grows cloudy, try letting the cloudy sediment settle and then use a pipette to remove the still-clear oil to a smaller, fresh bottle)
- The oil has thickened
However carefully we may store our essential oils, though, they do eventually go south. What to do? It seems a shame to waste them, even if the aroma has faded or shifted slightly and the aromatherapy benefits are diminished or gone. Here are some ideas for putting those oils to work even after they’re past their prime:
Freshen drains and toilets.
It only takes a couple of drops to make things smell better down there, and possibly kill germs (depending on which oils you use). That small amount roughly equates to the quantity of oil you’ll find in a scented bathing product. Do use discretion, however: because essential oils are volatile (i.e., flammable) and can cause harm if ingested in large doses, you don’t want to dump large amounts down the drain where they can leach into the water supply.
Drop a few drops in your shower pan or on the shower head to scent the bathroom while you bathe.
Remember: just a few drops! Citrus essential are ideal for this purpose, as are scents like lavender and eucalyptus. Be careful with any scent you may find overpowering or to which someone in the house may be allergic.
Create an impromptu room diffuser.
Place a few drops of oil (or a blend) on a saucer or in a custard cup. Old oils may not be as potent as new oils, but they can still make the air smell better.
Place a few drops of essential oil on a rag, throw a cotton ball with essential oil drops into a vacuum cleaner, place some on cedar shavings and put among clean towels, add some to a pumice bar and nestle in your drawer, and so on.
This is a great way to keep clothing and linens—in fact, your entire household!—smelling fresh throughout the cleaning cycle.
Freshen your trashcan.
Drop a bit in there to ward off stink.
Put a few drops in with the fabric softener or detergent.
Just don’t put the undiluted oil in direct contact with clothing, as it can leave stains.
Keep bugs at bay.
Even if your oils aren’t so fresh, they’ll still repel critters—as long as the oils still smell strongly. Citronella, eucalyptus, tea tree oil, and other essential oils can be added to candles (unlit!), dripped into potpourri, or placed in a small saucer or tea light holder to repel pests. Allergic to bees? They dislike peppermint and other strongly fragrant menthol or astringent oils.
There you have it! Thrifty ways to use up those aging oils, even long after they’ve passed their prime.