This is an ultrasonic. An ultrasonic is an invaluable tool in a Natural Botanical Perfumers' arsenal of nifty thingamabobs.
This is a relatively small ultrasonic, about a 2L capacity. For home use, you can get big ones -- 7 gallons, 10 gallons, way bigger than you need. For me, though, this little baby does just fine. It has provided me immeasurable hours of aromatic bliss. And just so you know, not only do my children tell everyone that my perfume studio is a meth lab, they also tell them that my ultrasonic is a vibrator, so . . .
How does one use an ultrasonic in perfumery manufacture? It's easy, really. Ridiculously easy considering the end result.
A Primer in Evulsions ~
In Steffen Arctander’s textbook “Perfume and Flavor Materials of Natural Origin”, he writes:
"A tincture is a prepared perfumery material, flavor material or pharmaceutical product. Tinctures can be considered alcoholic extracts of natural raw materials; the solvent is left in the extract as a diluent. Consequently, tinctures are not exposed to heat during preparation. There is no general rule governing the strength of perfumery or flavor tinctures."
Of ultrasonic extraction, he writes:
"Ultrasonic extracts are prepared flavor materials, or in a few cases, perfume materials. Several methods of extracting natural raw materials with the aid of supersonic sound vibrations have been described in scientific literature, and many extractors have been patented. A few European flavor and perfume material suppliers specialize in such extracts, e.g. Camilli, Albert et Laloue in Grasse, France. It is claimed that this method:
1) gives higher yields,
2) reduces the amount of solvent needed,
3) greatly improves the flavor or odor in the sense that they become more true to nature,
4) reduces the extraction time considerably,
5) makes possible an extraction with water or low-proof alcohol where this is otherwise not too effective.
. . . The finely ground raw material is suspended in the menstruum (solvent/alcohol) in the extractor. High-frequency vibration is applied, and in an amazingly short time, the drug is exhausted. Due to the better yield given by this method in comparison to ordinary extraction, the ultrasonic extracts are often cheaper in use than the old types of extracts. This method is particularly useful for extraction of flavors from sensitive (heat-sensitive) raw materials, e.g. coffee, spices, etc., but flowers and herbs are also treated by this method now, e.g., mimosa, thyme, etc."
Because the end-product of a tincture differs from a supersonic or ultrasonic tincture, the terms have been redefined to more accurately describe the procedures used to obtain the final raw material.
Tinctures are made by combining raw materials (herbs, seeds, grasses, resins, woods, etc.) with high proof grain or grape alcohol and allowing them to steep. Succussion, banging the container in which the tincture is held against one’s hand can be used, though this cannot be, and is not considered in any way similar to using an ultrasonic.
Evulsions are made by combining raw materials as described in the tincturing process with high proof grain or grape alcohol, and then placing the container holding these materials into an ultrasonic unit for a length of time as to extract, or pull, scent (or flavor) from the raw material into the menstruum (alcohol). By definition, evulsion means to forcibly extract, or to pull out.
Many natural perfumers have used this method of extracting high quality perfumery ingredients from evulsing raw materials at home using ultrasonic devices, such as jewelry cleaners or tattoo equipment cleaners, to achieve evulsions which rival the quality of expensive absolutes. Smaller devices can be utilized in producing small batches of evulsions; larger capacities, in the 2L or higher range, are much more desirable. There are not, as yet, any standards for ratios of raw material to solvent in the production of evulsions for the natural and botanical perfumer; however, the following information will help in solidifying a basic understanding of the techniques which produce high quality perfume materials.
For sample test batch sizes, try the following - the first numbers are the ratios, the second the number of grams of raw materials, the third the number of grams of alcohol, and the fourth how many hours the test should be put in the ultrasonic (my charts wouldn't work here, so I'm fudging).
1-1 50 grams 50 grams Six hours
2-1 66 grams 33 grams Six hours
3-1 75 grams 25 grams Six hours
3-2 60 grams 40 grams Six hours
Experiment with the ratios using the same raw materials to obtain the results you desire; for example, run a small test batch of powdered basil at the 1-1 ratio, another at the 2-1 ratio, and so on and so forth, and then perform evaluations for each resultant evulsion. You will find that certain raw materials will need a longer extraction time (many hours; 40+) to obtain a useable end product. Roots and resins may require a longer extraction time, while delicate fresh flowers and leaves need less extraction time. Experiment, experiment, experiment! Don't be afraid of your ultrasonic, love it.
Be sure to follow the operating instructions for your ultrasonic device to keep it in good working order and to avoid accidents. Fill the cavity *with distilled water so that the water level rises to the top of the cavity when you place the container of material into the ultrasonic, or use the minimum fill line as a gauge and adjust if the water level rises up and out of the cavity. Never run the ultrasonic with the water level lower than the minimum fill line (thanks Lisa!). Utilizing the chart above, determine the ratio of your experimental evulsion, pour the solvent into the bottle or jar (jars are preferred as the opening is much wider, which is helpful when using bulky raw materials) add in the raw material, close the jar tightly and place it in the water bath in the ultrasonic device. For the best results, allow the materials intended for evulsing to dry out or wilt, unless you're using delicate flowers, like hyacinth, jasmine, mimosa -- these you need to toss right into the alcohol after plucking. Just remember that too much water in the plant material can ruin an evulsion. Plug in the device and turn it on to the highest time allowed. Some devices can become hot when used for long periods of time. It is a good idea to allow it to cool down between sessions.
When your evulsion reaches the four hour mark (for the purpose of this experiment), remove the jar from the water bath, unplug the ultrasonic and pour out the water. Strain the raw materials from the jar using a mesh strainer, straining the fluid portion of the evulsion into a clean glass jar or bottle (use a funnel if necessary). Label the bottle of finished evulsion with the amount of raw materials to solvent, date of extraction, number of hours (or minutes) needed to finish evulsing, and then conduct an evaluation of the finished product. If you discover your evulsion is weak, you can begin the process over using the first extraction results into which you would add another batch of raw materials and conduct the experiment again. This would be a 2X (or two times) extraction.
For larger batches of evulsions, simply increase the number of grams to ounces and proceed as instructed above. You can also create infusions in the ultrasonic device if it has a heating element. Using either oil or alcohol, create an evulsion blend as instructed and place the bottle into the water bath of the ultrasonic device and turn on the heat. Experiment with time limits and test the evulsion every few hours for strength of scent.
Please see the previous post for instructions on how to get your hands on an ounce of my fresh hyacinth evulsion.