The Herbal Medicine-Maker's Handbook_ A Home Manual - James Green [48]
There is a universal disadvantage, however, in using water by itself as a solvent. As one can affirm from experiencing the forces of nature, the conservation of status quo is not the work of water on the surface of this dynamic planet. Water is not one to preserve a static condition of any substance or being; and this salient characteristic is reflected by an herbal preparation when using water as a sole menstruum. Except in its own frozen state or glacial form, water is not at all a preservative. On the contrary, its presence stimulates change and is a prime mover in the perpetual transmutation of forms (and aqueous solutions). Therein, true to its fine nature, the greatest disadvantage in the use of water as a menstruum is that it is not a preservative. In fact, water in its passionate promotion of change is a near antithesis to a preservative. Its remarkable solvency extracts large amounts of diverse substances, while its tissue penetration excites plant enzymes (although these organic catalysts are usually destroyed by high temperature), and the resulting solution of plant constituents makes up a fertile soup that can be an excellent media for enzymatic action and the growth of molds, yeast, and bacteria. These opportunistic organisms, in their spontaneous feeding frenzies, radically alter the state of the extract, and this alteration is usually not on the side of sensory aesthetics or palatability. So one is required to either consume a water extract within a day or two, freeze it, or add another substance that can interfere with destructive enzymatic fervor and insidious multiplication of microorganisms; and that is what some of the following liquids do.
ETHYL ALCOHOL
Alcohol is more selective in its extraction action, and therefore does not have as wide a solubility range as water. Ethyl alcohol is a good general solvent for extracting resins, balsams, camphors (most of these three are thrown out of solution by diluting them with water), essential oils, alkaloids and natural alkaloidal salts, glycosides, organic acids, chlorophyll, most coloring matter, nearly all the acrid and bitter constituents of a plant, un-crystallized, amorphous vegetable sugars, and one fixed oil: castor oil. Some sugars, proteins, gums, mucilaginous substances, and albuminous bodies are, however, capable of being mixed with dilute alcohol (a mixture of 50 percent water, 50 percent ethyl alcohol).
Alcohol refuses, however, to abstract gums, mucilaginous substances, starch, albuminous materials, or many mineral compounds, and it does not dissolve any appreciable amount of crystallized cane sugar.
In addition to its selective solvent properties, alcohol paralyzes enzymes, and at the same time prevents the growth of yeast, molds, other fungi, and most bacteria; so alcohol solutions seldom if ever ferment or putrefy. As a consequence of these reliable preservative properties, alcohol more or less diluted has long been employed as a solvent in the making of tinctures, fluid extracts (which are merely concentrated tinctures), and solid extracts. Though not preferred by some people, alcohol as a preservative is efficient and often necessary for the following reasons:
1. To eliminate microbial activity and preserve preparations almost indefinitely
2. To inactivate enzymes which are destructive to alkaloids and glycosides
3. To control destructive chemical decomposition of glycosides and saponins due to the presence of water
Alcohol mixes well with water (and glycerin) in all proportions. As you will find in your medicine-making experiences, alcohol equals water in importance as a solvent for many active plant substances, many that water, especially cold water, does not readily dissolve. It is also a uniquely important agent for the very fact that (for manipulative pharmacy) it adamantly excludes many other plant substances which water does dissolve,