Essential oils do best when stored tightly sealed in a cool dark place in order to preserve their quality. Essential oils are most commonly extracted by steam distillation in large copper kettles. Stored in this way, pure essential oils can last for years and retain practically all of their original chemical components and potency.
This extraction processes uses temperatures between 240 and 260 degrees (115-125C), WELL over the boiling point of water. So, by nature, essential oils are born from high temperatures and will remain stable (as long as they are capped tightly closed) even if left in a hot car. Refrain from opening your oils until they have cooled.
The three culprits that are the cause of oxidation (the breakdown of essential oils) are heat, light, and oxygen, so it is important to store your essential oils in a dark glass bottle, keep the lid on tight, and keep them cold.
Keep your oils in the smallest bottle possible with the least amount of air as oxidation is actually the biggest reason oils deteriorate. Only purchase what you will use pithing 6 months or rebottle into smaller glass bottles as you use up a large bottle.
Yes, Essential Oils may be stored in the freezer. If they freeze or form crystals that cause its appearance to become foggy, simply allow them to naturally return to room temperature before using them. The time it takes to “thaw” will depend on the oil and can range from minutes to several hours.
ANISE will freeze at temperatures below 50 degrees. So it is not unusual to have it turn a white waxy solid. Just warm it up in very hot but not boiling water to protect the glass bottle. DO NOT put it in the microwave!!! It will return to a liquid state and be perfectly fine.