Julia Lawless, in her book The Illustrated Encyclopedia of Essential Oils states, “When we peel and orange, walk through a rose garden or run a sprig of lavender between our fingers, we are all aware of the special scent of that plant. But what exactly is it that we can smell? Generally speaking, it is essential oils that give spices and herbs their specific scent and flavour, flowers and fruit their perfume.”
That about sums it up. Essential oils are natural oils that contain the “essence” of a plant. They are the liquid or resin that is distilled, pressed or extracted from different parts of the plant – leaves, flowers, bark, berries, root, needles, seeds, beans, peel, cones, wood, stalks etc. Essential oils are generally extracted by distillation, though some oils are gotten through other processes like expression or solvent extraction.
Sometimes the oil can come from different parts of the plant – a few plants (like an orange tree) contain several different essential oils in different parts. Orange essential oil is derived from the fruit, neroli from the flower blossoms and petitgrain from the leaves.
It takes many, usually hundreds of, pounds of plant material to make a pound of essential oil. It takes about 200 pounds of lavender to make a pound of lavender essential oil. It takes over 2000 pounds of rose petals to make a pound of rose essential oil. (That's why it's SO expensive!)
Essential oils can be used in making soap and making candles – as well as in making many other fragrant items like room sprays, lotions, bath salts and oils, balms etc. They are also, of course, the foundation for the whole practice of aromatherapy.
For the most part, they can be used in about the same concentrations, and used in the same ways as fragrance oils. Remember, many fragrance oils contain essential oils as part of their blends.
Some people may be concerned about the safety of essential oils - and rightly so. Essential oils are powerful organic chemicals. But the same care should be taken whether using fragrance or essential oils in your candles and soap. Chemicals are chemicals whether they're created in a lab, or created in nature. Just because something is natural doesn't mean it's safe to put in or on your body.
So which is better?
I love essential oils. I also love fragrance oils. I use both of them in my soaps and candles. I do not believe that either one is inherently better than the other. They both have their proper uses, cautions and advantages. Like with all things, it is up to us candle makers and soap makers to learn all we can so that we can make educated choices about the products we make.