They should be stored in a cool, dry place away from direct sunlight and should be kept in amber, or any dark-colored, bottles with tight lid. This prevents oxidation as well as contamination from taking place thus, preventing oil deterioration. These oils should not be stored in plastic bottles or be capped with rubber lids as pure essential oils can dissolve plastic. Just like any other type of oil, they are affected, or degraded, by extreme temperatures. Keep in mind also that essential oils are highly flammable so it is a good idea to store them away from other materials that could easily catch fire as well as from children.
Citrus oils should not be kept more than 6 months. They have a tendency to go rancid over time. Patchouli oils and sandalwood, on the other hand, get better as time passes by. Once your essential oils have become cloudy, the consistency has thickened or they started giving off a rancid smell, you have to dispose it.
Tags: aroma, carrier oils, Essential Oils, grape seed, hydrophobic liquids, jojoba, olive oil, organic, organic aroma, skin, sweet almond