Our basic concept is to harvest wind damaged Douglas Fir branches from local city parks. This is an environmentally conscious project. Harvesting downed branches helps with parks clean up and reduces fire hazard. Our waste material then goes forward to be used as mulch. During our first distillation of this Douglas Fir we had a somewhat disappointing yield of only 0.4% The oil is quite lovely however. This problem is not insurmountable.
First we brought the branches back to our distillery. We then chipped the branches in our small electric chipper. This proved to be very cumbersome and time-consuming.
The purpose for chipping the branches is to reduce the size of the material we are distilling, this enables us to get as much raw material into our still as possible. The more raw material, the merrier!
Our 100 gallon stainless steel steam distiller was then filled with chipped Douglas Fir branches. The steam was slowly brought into the retort at low pressure. After breakthrough (when distillate begins to flow from the condenser), we distilled for 1.5 hours. Upon opening the still we discovered that the plant material had been totally exhausted. Although the yield was somewhat disappointing.
I am not discouraged. I feel that if we wait a few more weeks, when the Douglas Fir buds begins to open, there will be more oil present in the plant for distillation. Although we can certainly distill during the winter months, it looks like spring and fall will offer the best yields.
Logistics must be worked out. The way we processed the material was time-consuming, and in the long run not financially feasible. Next time, we will use our large chipper to expedite the process of reducing the particle size. We are actually distilling the needles of the Douglas Fir, and we are not removing the needles from the branches.
Enough raw material needs to be brought to the distillery for at least two batches. As our distillery grows, we will be adding additional capacity.
This project can serve as a model to others who wish to help out their local environment, while manufacturing a product free from harmful chemicals and sprays (providing of course that your local parks administrators don't spray their trees) Fortunately the Douglas Fir trees in Portland parks are not sprayed.
Douglas Fir is a native species that does well here in Oregon, and in most cases the trees in our parks are adults, and simply have no need for spraying.
Along with making some beautiful oil, we also made lots of hydrosols. One of our staff members has taken the hydrosol home to be used in cleaning floors.