Liquid extracts or granules? Now that many Chinese herbalists are moving away from using raw, bulk herbs when prescribing for their patients, the question often arises as to what other forms of herb administration are available and how they compare. There are many factors to consider including potency, patient compliance, convenience, taste, product availability and shelf life. Practitioners that use granules/powders seem to be pleased with the results they get with their patients, but so do those using liquid extracts. Dave Ehrlichman gives an overview of Chinese herb liquid extracts, how they are processed differently than traditional Western herb tinctures, and how to think about dosaging and conversions.
We asked Dave Ehrlichman, owner of Golden Lotus Botanicals, to educate us about the extract process. The following is his summary of the processing and use of liquid tea concentrates / fluid extracts:
At Golden Lotus Botanicals, Chinese fluid extracts are typically concentrated to a 2:1 end ratio. This means that the equivalent raw herb conversion is 2 kg raw herb to 1 liter of end product, or 1 ml is equiv. to 2 gr (2000 mg) of crude raw herb. In this scenario, 1 teaspoon of liquid extract would be comparable to 1 cup of bulk herb tea, in which 16 grams of ground up, crude herb is made soluble and absorbable.
In terms of pounds to gallons, this translates to 16 pounds of raw herb, concentrated thru hot water decoction, yielding 1 gallon of end fluid extract. This ratio creates a substantially more concentrated product than a typical tincture commonly employed in western herbal practice.
Historically, Western herb tinctures are made from fresh or dry herbs that undergo a cold maceration of water and alcohol. Less water is needed for fresh plant material, more for dry material. There are differing traditions that prefer using fresh over dry herbs in order to more effectively extract the "vital force" from the herb material, whereas others prefer dry material because it offers greater concentration with less water weight.
Similar to the difference between TCM and Japanese Kampo acupuncture needling techniques, herbal medicine also employs different approaches depending on the tradition. In the Kampo tradition, very fine, thin needles are used for acupuncture, and herbs are generally prescribed in relatively low doses for a gentle, more subtle approach. In contrast, the TCM the tendency is towards the use of larger needles with strong stimulation, and herbs are prescribed in relatively large doses.
Despite the apparent contradictions and differences in approach, both systems work well. Similarly, in herbalism in general, we see opposite polarities of concentration, dosage, and dilution reflected in fresh plant tinctures, homeopathy, and concentrated / standardized TCM herbal medicines. All work well depending on the patient, the practitioner, and constitutional considerations, despite their differing methodology.
Commercial herb tinctures are commonly made at a 1:5 ratio, meaning that 1 part herb is used to 5 parts menstruum. The menstruum, or liquid used to extract the constituents of the herbs, typically consists of 30-60% pure grain alcohol content and a good amount of water. The end product is relatively dilute. The average potency strength of the typical tinctures at Golden Lotus Botanicals is closer to 1:2, which yields a more concentrated extract than a 1:5. However a 1:2 is very different than a 2:1. A 2:1 potency indicates 2 parts herb to 1 part menstruum of finished product. So, the higher the number on the left of the ":", the more concentrated the end product, whereas, when the number on the right of the ":" is higher, a greater dilution is indicated.
Generally, a tincture is concentrated by way of "dual" or "triple" maceration. This means that additional raw herb material is added to the ending menstruum yield of the prior batch. Additional water and alcohol are added as needed to cover all the dry material. This "cold processing" maceration, also known as "dual extraction", usually takes several weeks to run its extraction course, depending on the number of concentrations involved. This is in contrast to hot water "cooking" methods that usually take a few hours.
For example: A typical homeopathic mother tincture is a 1:10 concentration, which is quite dilute. Whereas a 10:1 extract would basically be a concentrated powder extract of solids only, with no water or alcohol remaining. Of course, in homeopathy, toxic herbs are often used and thus the high dilution factor is very important. For example, one would not take fresh aconite in full concentrated potency without moderating its toxicity through a lengthy cooking time (as in TCM) or without substantial dilution (as in homeopathy).
Dilution does not necessarily means less potency. For example in the case of homeopathy, less is more! As the extract is repeatedly diluted, it becomes "potentized" through succession. This is considered "vibrational" as it actually becomes more potent with dilution, despite the virtually undetectable amount of any physical solid materials remaining. The principle at play here has to do with the Vital Force of the qi of the herbs, by way of stripping away all the physical/ material properties. In a sense, it clears the physical matter to get to the immense potency of the qi or spirit essence of the plant.
However in Chinese herbology, the tradition has been towards strong physical / biochemical doses, where concentrations are high, serving sizes are large, and the "spirit" of the herb is not so focused on as in the way of homeopathy.
In the processing of concentrated Chinese herbs, tradition guides us to uses hot water extraction methods, even though modern herbalists have explored using extractions of both water and alcohol, and hot and cold. TCM traditions are concerned with the heating properties of alcohol, thus many prefer to use it only in the realm of tonics and wines for rheumatic and topical use. However it should be noted that alcohol does act as a very effective carrier for the herbs and can extract the "essence" of the plants and deliver them quickly into the system, making it particularly effective for certain formulas and patterns.
In Chinese herb fluid extractions, we use a low temperature (below 105 degrees) water extraction to prevent the breakdown of the delicate constituents such as volatile oils and aromatics. Then adding sufficient water to cover the very absorbent dry material, the process is repeated several times by adding new herb material to the obtained liquid yield of the prior batch. This is continued until the desired end concentration is reached. After this cooking process is complete, we add alcohol to the cooked but unfiltered herb mass and let is macerate for some time as the hot decoction cools down. This allows any beneficial alcohol soluble compounds to be extracted, without overly affecting any "cooling" nature of the herbs.
Once maceration is complete, the herb matter is pressed and filtered, yielding a concentrated end product with a 20% alcohol content, rich in vital potency and flavorful aromatics. This alcohol content is important for not only enhancing the absorption of the herbs, but more importantly for a reasonably good shelf life of 1 - 2 years. This would not be possible with water only extracts unless some other preservative was employed. For dosage guidelines and considerations, and a table of conversions for mixing tincture formulas, click here.
I hope that this quick summary provides some useful insight into this aspect of herbology and its relevant in the area of fluid extractions.
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