The Nature of a Good Blend
Essential oils in good aromatherapy blends should be all-natural, pure, contribute a benefit, and work synergistically to support and enhance one another for the desired effects. Before blending, it is a good idea to have an overall understanding of aromatherapy essential oils, individual oil characteristics, and aroma profiles.
 
The Nature of Oils
Aromatherapy essential oils are very volatile, meaning they change easily from a liquid to a vapor. The three major changes that take place when an essential oil vaporizes are known as the top note stage, middle stage, and dryout stage. Their corresponding aroma profiles are known as top notes, middle notes, and base notes. The top notes contain the first most volatile and unstable aroma compounds that are subtle and last for only seconds. The aromatic body is more developed and balanced in the middle stage as some top notes may still linger and base notes develop. Compounds in the base notes become more apparent due to a slower volatility. A slight, thin dryout note is detectable after evaporation that is at times powdery and bittersweet. This dryout note can be referred to as the matrix or skeleton of the oil.

Some oils with certain characteristics are classified into these profiles. For example, bergamot oil, a delicate, volatile oil is referred to as a top note oil. Clary sage which is a balanced, moderately retentive oil, is referred to as a middle note oil, while a deep, rich tenacious oil such as patchouli oil is regarded as a base note oil.

Although aroma characteristics may change during a scent’s existence, a well balanced oil balances top, middle, and base notes, keeping the aromatherapy benefits throughout the stages.

Ways to Learn from Essential Oils
Experiment with oils before blending, placing a drop of oil on blotter paper or unscented tissue. Inhale and write down notes on what the scents are reminiscent of, how the aroma changes during the stages, and benefits of the experience. In this way, the notes can be referred to in the future. Think of how the specific oils in a blend work, what parts of the oils to enhance, and what aspects to tone down. Learn to match aromas with benefits and experiment with amounts and combinations, keeping notes so successes can be repeated.