Use opaque glass bottles to avoid light and heat.
1. Direct light and high temperature will affect the quality of plant essential oils and base oils.
2. The most sensitive are lemon oil and European juniper oil. These two oils can be stored in a sealed bottle for about one year. To ensure the quality of the essential oils remains unchanged, they can be placed in the refrigerator.
3. Peppermint oil, fennel oil, and essential oils extracted from plant wood and flowers are quite stable and not easy to deteriorate.
4. The properties of some essential oils are similar to those of wine, that is, the longer the storage years, the better the quality of the oil. Such oils include sandalwood oil, rose and jasmine oil.
5. Usually, unopened base oils can be stored for more than two years. But once opened, air will enter and produce oxidation, causing the oil to deteriorate.
6. To delay deterioration, wheat germ oil or vitamin E capsules can be added to the base oil.
7. Base oils basically have almost no taste except for a slight nutty taste. If the expired base oil contains a distinct odor, it can be easily smelled.
8. Usually, unused base oil can be stored in a sealed container in the refrigerator to slow down its oxidation.
