One of the major developments in the herb industry involves improvements in extraction and concentration processes. The water is serving as a solvent in removing some of the medicinal properties from the herb. Teas often are better sources of bio-available compounds than the powdered herb, but are relatively weak in action compared to tinctures, fluid extracts, and solid extracts. This soaking period is usually from several hours to several days in length, and some herbs may be soaked for much longer periods of time. The resultant solution is then pressed out, yielding the tincture.
Fluid extracts are more concentrated than tinctures.
Commercial fluid extracts usually are made by distilling off some of the alcohol, typically by using methods that do not require elevated temperatures, such as vacuum distillation and counter-current filtration. The dry solid extract, if not already in powdered form, can be ground into coarse granules or a fine powder. A solid extract also can be diluted with alcohol and water to form a fluid extract or a tincture. The potencies, or strengths, of herbal extracts are generally expressed in one of two ways. If they contain known active principles, their strengths are commonly expressed in terms of the content of these active principles.