Last Friday, Jasmine, Austin, and I were at the Green Acres Pick-Your-Own farm in Palisade evaluating the lavender plots to determine if they were ready to harvest to process for their oil. Two Lavandula angustifolia cultivars, ‘Betty Blue’ and ‘Folgate’, were in full bloom. Regrettably, they were not at the proper stage to harvest and distill for their high quality oil. We spent the rest of the morning distilling dried lavender floral stems from last year’s harvest in preparation for the 10 cultivars scheduled for distillation this year.
This lavender distillation project is designed to determine the quality of the essential oil produced in western Colorado. Several publications indicate lavender plant essences are of higher quality when grown at high elevations. This project is designed to determine if that is truly the case and will give us a baseline for the oils produced in this area. After distillation, the oils will be examined using GC/MS, gas chromatography coupled to mass spectrometry, a laboratory procedure that provides the profile of the essential oil. There are international standards for the essential oils of lavender and the hybrid lavandins based on what is grown in France. There is a minimum and maximum levels (percentages) for each of the volatile organic compounds (VOCs) found in these oils and we want to determine how our lavender and lavandin compare with the rest of the world. These oils are often sold according to the levels of these VOCs with some buyers basing their purchase on the GC/MS.
The key to producing the maximum amount of oil involves packing the distillation chamber with floral stems and buds as tight as possible and ensuring a maximum of steam is produced in the water-filled chamber below. Stems need to be included in the distillation chamber (called the ‘charge’) to ensure steam can move through and reach all the buds. Packing the charge with buds only results in a dense mass through which the steam cannot travel and much of the oil is lost in the process.
I’m using the term bud loosely as that is the term most of those in the business call the calyx where the oil glands are located. Oil and the watery distillate, called hydrosol, comes out of the condenser and accumulates in a collector. The oil floats on top of the hydrosol and thus can be decanted off, leaving the hydrosol to be used as a base for lemonade and other drinks, to make lotions, shampoo, toothpaste, and even as an all-purpose cleanser. The oil is a high price commodity with many uses. Sprigs and Sprouts and the other lavender growers in the area can provide you a more detailed description of its uses than I can in the limited space I have available in this article.
The essential oil stainless steel pot still Austin, Jasmine and I am using for our distillation project holds between two and three gallons of flowers and stems depending on how tight it is packed. The Newhouse essential oil pot still recently purchased by Sprigs and Sprouts in Palisade processes 10 gallons of buds and stems at a time. Ruth and Linda, co-owners of Sprigs and Sprouts, gave me the opportunity to work with their still on Tuesday along with Joseph Brown, a local glass blower and builder of stills. This was the first time the S&S still had been used and the essential oil it produced was clear and beautiful. With the number of people planting lavender in western Colorado and the need for distillation, the stills available in the area will be hard pressed to keep up with the demand for their use.
Rose petals, juniper needles, mint and many other plants can be distilled for their essential oils and I expect those who have a still will be experimenting with the many plants known for their essences. The harvest and distillation of hemp seed for its oil is another possibility once the growing of industrial hemp is approved in this area.
Dr. Curtis E. Swift is a retired horticulture agent with the Colorado State University Extension. Reach him at Curtis.Swift@alumni.colostate.edu or check out his blog at http://SwiftsGardeningBlog.blogspot.com. He owns Swift Horticultural Consulting and High Altitude Lavender.