Can different distillation practices change the oil quality? Yes!
Commercial distilleries push process pressure over 5 pounds and up to 300 degrees Fahrenheit, which fractures the molecules. This speeds up the extraction process, and yet they are still able to capture the top notes for the perfume industry. Their distilling time can be no more than 40 minutes.
Our distillation of lavender essential oil takes a minimum of 1 hour. When the commercial distilleries extract only for the purpose of the aroma such as for the perfumers, once the larger molecules come out, which are generally the fragrance compounds, the boiler is shut off because it burns 25 to 38 gallons of diesel fuel per hour at 5.50 Euros, which equals $7.36 a gallon, to retrieve maybe 1 or 2 percent more oil.
I have found after distilling oils on five continents around the world, above and below the equator, that most of the time the therapeutic molecules are some of the last molecules to come out, which may take 1½ to 3 hours more. For example, in our distillery in Spain, we use full-agitation to distill frankincense essential oil for 12 hours minimum. In Salalah, we use partial agitation and distill frankincense for 16 hours.
Agitation is a process that grinds the resin into coarse powder. It is similar to the agitation of the old-time washing machine, where the paddles move back and forth, beating the clothes. In this case, the paddles break down the resin, which is very gummy and will easily stick together, impeding the release of the oil. For this reason, the constant agitation is important to keep the powder from clumping at the bottom of the cooker. This agitation also ensures greater steam saturation for greater essential oil extraction as the steam travels up through the powdered resin.
Incensole acetate, which is a very important compound found in frankincense resin, only shows up after 11 hours of distilling with agitation and 15 hours without agitation. Incensole acetate is considered a major constituent, which is sought after to support many body functions. It works well as a companion to the boswellic acids in its medicinal attributes.
To be continued . . .