How Essential Oils Are Produced

All plant aromas can be attributed to the presence of essential oils, which perform vital functions in the life cycle of plants. Some aromas produced by essential oils serve to attract pollinators. Some aromas repel pests or discourage grazing animals from eating the plant. Others protect plants against infection by bacteria, viruses, and fungi.

For commercial use, huge amounts of plant material are needed to produce small quantities of essential oils, which explains why some essential oils are so costly to buy. For example,  3 to 6 pounds of eucalyptus leaves are used to make 1 ounce of its essential oil. Ten to 20 pounds of lavender flowers are used to make 1 ounce of its essential oil. Production of 1 ounce of jasmine oil requires 160 to 280 pounds of flowers. And, 2,000 rose petals are needed to make a single drop of rose oil.

Several different techniques can be used to extract essential oil, depending on the plant.

Steam Distillation: 

Approximately 80 percent of plant essential oils are obtained by steam distillation – a process that uses steam, heat, and condensation to separate a plant’s essential oils from its solid and water components. This technology uses no solvents, so the product is very pure. Essential oils produced this way include lavender, rosemary, peppermint, and eucalyptus.

Solvent Extraction:

For very delicate plants easily damaged by heat, other extraction techniques are available. Solvent extraction uses liquid solvents to dissolve and extract essential oils from the plant; the solvent is then evaporated under pressure. The initial product, called a concrete, is a sticky substance that contains plant waxes and pigments in addition to essential oils. The concrete can be sold as is or further refined to create a product called an absolute. This process is expensive, so it’s generally used only to extract desirable and costly fragrances {like jasmine} that can’t be produced through distillation. Solvent – extracted concretes and absolutes can contain traces of the solvents used to make them; so they aren’t appropriate for therapeutic use but are fine to use as perfumes.

Supercritical Carbon Dioxide {CO2} Extractions:

This newer technology uses carbon dioxide gas under low heat conditions to extract essential oils. Because less heat is used, the aroma of the essential oil is very close to that of the original plant. The final product is also free of solvent residues and is considered very pure. But the equipment needed for CO2 extraction is expensive, as are the oils produced.

Two types of essential oils are produced through CO2 extraction using slightly different technologies. One, called a selective extract, is a liquid composed mainly of volatile compounds. Oils produced this way include frankincense and myrrh. The other type, called type, called a total extract, contains volatile components as well as fats, waxes, and pigments with medicinal properties. This technology is used to produce essential oil extracts of carrot seed, calendula, chamomile, and vanilla. It’s also used to manufacture high-quality herbal extracts.

Cold Expression:

The essential oils of citrus fruits such as lemons, grapefruits, oranges, and limes are found in special oil glands in the rinds of these fruits. These oils are often extracted through a process called cold expression, which involves crushing the rinds to press out the oil, much like the way olive oil is produced. Citrus oils can be also be produced through distillation.


The oldest method for producing essential oils, rarely used today, is called enfleurage. The procedure involves placing fragrant blossoms on solid sheets of animal or vegetable fat and allowing the scent of the flowers to permeate the oil. When the fragrances in the blossoms are exhausted – having been absorbed by the fat – they are removed and replaced with fresh flowers. This process is repeated until the fat is saturated with volatile oils. A solvent can be used to extract the oils from the fat, or the fat can be used as is, in the form of an enfleurage pomade. Before the advent of solvent extraction, enfleurage was the only method available for extracting essential oils from delicate flowers such as rose, jasmine, and tuberose. This is a very old system of extraction that traces its origins to ancient Egypt, where fragrant flowers were extracted in animal fat and used to perfume the body.

essential oil room sprayHydrosols:

Hydrosols – true “flower waters” – are by-products of the steam distillation of essential oils. A hydrosol is the water component left behind when a plant’s essential oil is separated out in the distillation process. Hydrosols contain water-soluble compounds that make them fragrant and soothing to the skin.

Two of the best known and most popular hydrosols are orange water and rose water. Both have traditionally been used in cosmetics and for culinary flavorings. Hydrosols also make refreshing, aromatic body mists and skin toners, and these are sold in spray bottles. Some commercially available hydrosols include lavender, geranium, chamomile, rose, neroli {or orange blossom}, and rosemary. When purchasing a hydrosol, look carefully at the label to be sure it is a true hydrosol and not aromatic water, which is a blend of water and essential oils.


Dilutions for Common Use of Essential Oils:

Essential oils are extremely concentrated. You can benefit from just a few drops diluted in water or a carrier oil, lotion, or cream. Good carrier oils include sweet almond, grapeseed, and olive oils.

Use and Dilution

  • Use: Aromatic water {body mist} – Dilution: 10 drops per 1 oz. water
  • Use: Bathwater – Dilution: 3-6 drops per tub
  • Use: Body or facial oil – Dilution: 6-8 drops per 1 oz. carrier oil
  • Use: Footbath – Dilution: 5 drops per basin of water
  • Use: Massage oil – Dilution: 6-8 drops per 1 oz. carrier oil
  • Use: Room spray – Dilution: 15-20 drops per 1 oz. water
  • Use: Skin cream or lotion – Dilution: 6-8 drops per 1 oz. lotion or cream
  • Use: Steam inhalation – Dilution: 3-5 drops per 1 quart steaming water