In addition to being a celebrated savory seasoning, rosemary has a time-honored tradition of medicinal and therapeutic use. For centuries, it has been used to enhance memory, promote hair growth and relieve pain and tension. While none of its professed health benefits have been scientifically proven, studies confirm that rosemary is rich in antioxidants and contains natural anti-microbial properties. (See Reference 1)
Rosemary's essential oil is popularly used in aromatherapy and massage treatments since it's believed to relieve stress and improve concentration. Cold-pressing and steam distillation are common methods used to extract essential oils from herbs like rosemary. However, these techniques usually require extensive experience and the use of complex apparati. Below is a simple stovetop method that uses low-heat and a grapeseed oil base to harness the essential oil of rosemary.
Extract Rosemary Oil
If working with fresh rosemary, allow it to dry out in a warm, dark place for several hours. Make sure the herb has lost most of its moisture, otherwise the essential oil can become contaminated with mold and spoil.
Strip the leaves from the woody stalks of your dried rosemary.
If using a double-boiler, fill the bottom pot with water and add two to three ounces of rosemary leaves to the upper vessel. Cover with two cups of grapeseed oil. Simmer on low heat for three hours. If using a crockpot, combine the rosemary leaves with the grapeseed oil and heat on the lowest setting for three hours.
Strain the oil into a clean, sterilized glass jar. Seal and set aside in a cool, dark place.