Chapter 12

Essential and Carrier Oil Basics

Most plants produce essential oils in small quantities, but the plants commonly called “aromatics” (because of their strong scents) create enough for us to harvest and enjoy. Essential oils can cause irritation and other problems if applied directly to the skin and must be diluted with another oil commonly called a carrier oil. The carrier oils covered in this chapter can be used with essential oils as well as the herbal remedies that require an oil.

Essential Oils

Our sense of smell is intimately linked with memory and emotion. This is because the olfactory cortex of the brain is an area closely tied to the limbic (emotional and visceral) system. There are thousands of olfactory receptors in a small area at the top of each nasal cavity, and as we breathe in, air passes over these receptors and information is carried along a nerve into the brain. Essential oils provide immediate access to this rich storehouse of memory and emotion, which is why aromatherapy can be a powerful treatment. However, the term “aromatherapy” is a limited description of essential oil uses. They can be used topically to fight infection, heal skin problems, soothe sore muscles, and ease joint pain. In steam inhalations they can relieve congestion.

Plants produce essential oils for various functions such as aiding growth, attracting insects for pollination, and protecting against fungi or bacteria. Essential oils are obtained from various plant parts, and some plants may produce separate oils from different parts. For example, lavender essential oil is produced from the combination of leaves and flowers, whereas, angelica yields two separate oils from its seeds and roots. Essential oils are obtained from:

• leaves, stems, twigs

• flowers, flower buds

• fruit or the peel

• wood, bark

• resin, oleoresin, gum

• roots, rhizomes, bulbs

• seeds, kernels, nuts

Most of us have an idea of what an essential oil is, but the term is often mistakenly applied to a broad range of aromatic products from almost any natural source. Two key aspects to essential oils are that they dissolve in alcohol or oil but not in water, and that they evaporate when exposed to the air, which is why they are also called volatile oils. Most essential oils are liquid, but some, such as rose oil, may become a semisolid depending on the temperature. Some oils are solids. However, the defining factor is the method used to extract the oil from plant material. Essential oils are obtained through the processes of distillation and expression. Anything else is an aromatic extract, which is most often obtained by solvent extraction. The products created by solvent extraction contain both volatile and nonvolatile components.

The oldest and easiest method of oil extraction is called expression, or cold pressing. Cold pressed may be a familiar term for those who enjoy cooking with olive oil. For essential oils, this extraction process works only with citrus fruits because they hold high quantities of oil near the surface of their rinds. Depending on the plant, the whole fruit or just the peel is crushed and then the volatile oil is separated out using a centrifuge. This simple mechanical method does not require heat or chemicals.

The most prevalent process for extracting essential oils is through distillation, which can be accomplished using steam or water. In the distillation process, the water-soluble and water-insoluble parts of plants are separated, allowing the essential oil to be collected. Sometimes products are distilled a second time to further purify the oil and rid it of any nonvolatile material that may have been left behind the first time.

When steam is used in the distillation process, it is pumped into a vessel from underneath the plant material. Heat and pressure within the vessel, produced by the steam, causes the plant material to break down and release its volatile oil. The oil becomes vaporized and is transported with the steam through the still into a condenser, where it is cooled. This returns the oil and water to their liquid states. Depending on the density of the oil, it will either float to the top or sink to the bottom of the water. Either way, it is easily separated out. Different plants, as well as various parts of plants, require different amounts of time and temperatures for distillation.

In the water distillation process, plant material is completely immersed in hot water. This process uses less pressure and slightly lower temperatures than steam distillation. Nevertheless, for some plants, such as clary and lavender, steam distillation works better.

After the essential oil is separated from the water in these distillation processes, the water itself is an aromatic by-product called a hydrosol. Traditionally these have been called floral waters (i.e., rosewater) and contain the water-soluble molecules of aromatic plants. Hydrosols are also called hydroflorates and hydrolats. Hydrosols should never be used in place of flower essence remedies as they are not prepared under the same conditions required for consumable products.

The term “flower essence” may cause some confusion because this product is not fragrant and it is not an essential oil. A flower essence is an infusion of flowers in water, which is then mixed in a 50 percent brandy solution. Whereas the brandy acts as a preservative for flower essences, hydrosols being mostly water, can go bad. Just because flower essences contain alcohol, they should not be confused with tinctures, which are made with much higher concentrations of herbs. We will learn more about tinctures in Chapter 13.

Carrier Oils for Essential Oils and Herbal Remedies

Carrier oils are also called “base” or “fixed” oils because they do not evaporate when exposed to air as essential oils do. Essential oils are very lipophilic, which means they are readily absorbed by fatty oils and waxes. Because most carrier oils are produced from the fatty portions of plants—such as seeds, kernels, or nuts—they absorb essential oils, which become diluted as they are dispersed throughout the carrier oil.

Carrier oils come from fatty plant matter, so they can go rancid if not stored properly. Like essential oils, they should be kept in dark, airtight bottles away from sun and artificial light. The shelf life of carrier oils depends on the type of oil. Storing them in the refrigerator can help keep them fresh and extend their shelf life slightly. However, like anything else we keep in the fridge, it can eventually go bad. If an oil does not look or smell right, throw it away.

Most carrier oils have their own smell, which can be sweet, nutty, herbaceous, or spicy. These are not as strong as the aromatic oils and generally do not interfere with the fragrance of essential oils. At this point, you may be thinking that the standard vegetable oil from the supermarket doesn’t have any smell. This is true because chemical solvents are used to bleach and deodorize them as well as kill bacteria. While this extends the shelf life of the oil, it also means that we are putting chemicals into and onto our bodies when we use them.

When choosing an oil for making remedies, or cooking oil for that matter, select one that is unrefined and, if possible, organic. Refined oils are produced as cheaply as possible with the aid of solvents, and more and more often they are being produced from genetically modified plants. Refined oils are produced to have no odor and very little to no color. As a result, these have little nutritional or healing value. In addition, some of the plant material harvested to make these oils is often stored for a year or more before being processed. When it is finally hauled out, the raw material is washed with chemicals to remove any mold that may have grown on it while in storage.

A cycle of processes is used because after one process adds something to get rid of the oil’s natural odor or color, it is followed by another process to remove whatever was put in to do the job. After wringing most of the nutrients out of the oil, it is subjected to one last process called winterizing, which keeps it from turning cloudy at lower temperatures. Unrefined oils may appear cloudy when stored in the fridge, but this does not change their chemical compositions or harm them. I prefer the clouds and shorter shelf life for my oils.

There are a number of terms applied to oils. Partially refined means that the oil was subjected to some of the chemical processes, which most often includes bleaching, deodorizing, and winterization. The word pure just means that it was not mixed with any other type of oil. The word natural on the label means that it was not diluted with a synthetic oil.

An unrefined oil may be labeled “cold pressed” or “expeller pressed,” which means that it was not subjected to high temperatures. Plant material is usually put through a press more than once in order to squeeze out as much oil as possible. Oil that is extracted from the first pressing is called “virgin.”

Commonly Used Unrefined Carrier Oils
Oil	Shelf Life	Description	Attributes
Almond	12 months	Light texture; medium viscosity	Softens, soothes, and nourishes the skin; absorbs well
Apricot kernel	6–12 months	Light texture; medium viscosity	Heals dry, sensitive, inflamed, or irritated skin; easily absorbed
Avocado	12 months	Heavy texture; thick viscosity	Heals and nourishes the skin; usually mixed with a lighter oil for use
Borage seed	6 months; refrigerate	Light texture; medium viscosity	Heals and rejuvenates the skin; usually mixed with another oil for use
Coconut	1–2 years	Light texture; medium viscosity	Moisturizes and protects the skin; easily absorbed; solidifies at cool temperatures
Hemp seed	6–12 months; refrigerate	Light texture; medium viscosity	Nourishes the skin; easily absorbed
Jojoba	Up to 5 years	Heavy texture; medium viscosity when warmed; actually a wax	Excellent moisturizer, good for inflamed or irritated skin, resembles the skin’s natural oil; solid at room temperature
Olive	1–2 years	Heavy texture; thick viscosity	Good for dehydrated or irritated skin; usually mixed with a lighter oil for use
Sunflower	12 months	Light texture; light viscosity	Especially good for delicate skin
Wheat germ	12 months	Heavy texture; thick viscosity	Soothes and regenerates the skin; usually mixed with a lighter oil for use

[contents]