Essential oils are especially precious because of the benefits they bring to our lives and those around us. An impressive amount of raw material is used to obtain each magic drop. Thus, it is important to pay more attention to how we store them, in order to maintain their maximum potential for as long as possible.
The average shelf life of essential oils is about three years, but some oils retain their properties for four to eight years, such as Vetiver, Sandalwood or Patchouli essential oil; citrus oils can be used within a year after opening the bottle because it oxidizes very quickly.
How do we know if an oil is no longer valid? First of all, smell is the most relevant clue. If it is different from what we knew it would be a specific smell or if the original aroma is altered or rancid, it means that the oil has "passed its time". Also, if the consistency, color or clarity of the oil changes over time, it's time to put it aside. Freshly expired oils can be used in household cleaning products, some nice ideas on this topic can be found here. Avoid using them on the skin or inhaling directly.
The external factors that determine the degradation of essential oils are:
1. Oxygen: frequent and prolonged exposure of oils to air leads to their oxidation and thus to their deterioration and evaporation.
2. Heat: high temperatures can change the chemical structure of essential oils, losing their original properties. They are flammable and each oil has its own temperature at which it will ignite.
3. Light: Exposure of oils to direct sunlight can affect their color and, consequently, their composition.
How do we store essential oils?
~ Keep oils in dark bottles, such as brown or blue, as they filter out ultraviolet light, which otherwise affects the composition of the essential oil.
~ Do not store oils in plastic containers under any circumstances, as they are corrosive and will attack the packaging.
~ Make sure the bottle has a sealed cap. Screw caps have this form of plugging, which prevents air from entering the glass and oxidizing the oil, nor does it allow the oil to escape through evaporation. Remember to tighten the lid immediately after use.
~ It is recommended to keep essential oils in a cool and dry place, to avoid heat and light. You can keep them in a closet in the bathroom, kitchen or on a bookshelf, where direct sunlight does not reach. Even if the dark glass filters UV, the natural heat will speed up the oxidation process.
~ Storage temperature is important, but even more important is the prevention of temperature fluctuations. In this sense, the fridge can be a suitable place to store essential oils, set between 5-10 degrees Celsius. Some oils may solidify, but their quality will not be affected and the oil should return to its liquid state after being brought to room temperature. Remove the oils from the refrigerator about 12 hours before using. Do not store in the freezer, as freezing can damage the oil and reduce its quality.
~ Essential oils stain easily, so be careful with the surface on which they are stored. Contact of oils with certain materials, such as paper, plastic, or painted / polished surfaces, could damage these spaces.
~ Essential oils are flammable. Do not leave them near a fire, candle, stove or any other heat source.
~ Keep essential oils out of the reach of children!