The chemistry behind essential oils is relatively complex. In the plant form, the properties change at different stages of the day (for example, according to sunlight) and year, also depending on the part of the plant from which the substances are distilled (root, wood, bark, leaves, stem, flower, seed) soil, and even climate. Oils are composed mainly of terpenes, sesquiterpenes, esters, alcohols, phenols, aldehydes, ketones and organic acids.
Essential oils contain vitamins, hormones, antibiotics and antiseptics. The yield from essential oils is between 0.005 and 10 percent of the plant’s weight. For example, 50 kg of plants are required to produce 1 kg of eucalyptus oil, and up to 150 kg of plants in the case of lavender oil. For sage, thyme or rosemary, the ratio is even higher – 500 kg of plants per 1 kg of oil. And, for example, rose oil can require up to 3,000 kg per kg of pure oil.