For centuries, the process of creating an essential oil has been a ritual to capture the spirit of a plant. Herbs and flowers were harvested and distilled into a tiny vial of liquid: what the first perfumers considered to be the plant’s “life force.” Essential oils exist in certain plants for several reasons: to attract pollinating insects, to repel unwanted pests that can threaten a species’ survival, or to prevent other plants from growing nearby which would compete for sun and soil. Like weather, the cells within a plant that create essential oils are always changing in reaction to external factors, meaning that there will be subtle differences in an essential oil harvested from the same plant grown in different climates. Even lavender from the same farm could differ slightly if it is harvested in late June instead of early August.
Steam distillation is the most common method of extracting an essential oil from a plant, where a fresh harvest is placed into a still that is similar to the device used to distill alcohol from grain. Water and plants are combined in a pot, then heated to boiling. The vapors that are produced run through a thin copper tube and become liquefied as they cool, creating a distillate of hydrosol and essential oil. The hydrosol is then filtered out, and the delicate essential oil is bottled up.
Expression is the other method of creating an essential oil. Generally used for citrus oils like orange and grapefruit, expression is similar to the cold-pressing process common for creating juices. Fruit rinds are placed in a container where they can be punctured and squeezed, releasing the oils. The runoff is channeled into a container and is left to settle, so that the oil separates from the juice and water.
Our sense of smell is connected to the place in our brain where memory and emotion are stored, making scent a channel to connecting with our unconscious selves. Dripping a bit of essential oil on the palm or lighting a candle that scents the air in a room brings us straight into the natural world where that plant once lived, transporting us into a French lavender field on a warm July afternoon or a shadowed forest on a cool September morning.