Widespread production of brandy began in France in the 17th century as a means to utilize poor quality wines. Brandy became the preferred form of alcohol for medicine, but in northern areas whiskey was also used due to its local availability. By the end of the 18th century tinctures were an important class of medical preparations. In the early 19th century Aeneas Coffey discovered that by using a continuous column still most impurities could be removed and 94-96% pure ethanol could be produced. To eliminate the remaining impurities this distilled alcohol could be diluted, filtered through charcoal, and then rectified, or redistilled. This type of neutral spirit then became the standard solvent in the manufacture of most cordials, liqueurs, and tinctures. Liqueurs that contain one predominant herb were developed to be used after meals as digestive aids such as Anisette, Kummel, and Creme de Menthe.
Pharmacies were known for having large bottles, called carboys, sitting in their windows. These were used for making tinctures by soaking crude herb drugs or chemical substances in alcohol, a procedure known as maceration. In the early 19th century the process of percolation was developed to help concentrate the extracts. They could then also be standardized in content to produce fluid extracts of plants. Percolation was further refined through the invention of the Lloyd extractor, or cold still, by the American John Uri Lloyd. He contributed to the standardization of cordial elixirs and developed his specific medicines as the epitome of quality in herbal medicine in the late 19th century.
After that time the popularity of alcoholic extracts of herbal medicine began to steadily decline as the production of purified active constituents and synthetic drugs took precedence. A few tinctures, fluid extracts, and elixirs are currently officially recognized, but many are only used as flavors. On the other hand public interest in herbs and their use has increased over the last several decades and continues to grow.
Differences in alcohol
Brandy and whiskey were listed as official drugs in the U. S. Pharmacopeia until the 1940's and ethanol was listed until 1975. Though brandy, whiskey, and neutral spirits can all be used as solvents, there is usually no designation on herbal extracts as to what type of alcohol is actually employed. Yet significant differences exist between them. The different congeners in each produce different flavors, aromas and effects of the distillate. These compounds vary depending upon what plant source was fermented. The main congeners are higher alcohols that make up what is called the fusel oil. These are more potent depressants and more toxic than an equal amount of ethanol. Alcohol distilled from potatoes has the highest amount of fusel oil which is almost pure amyl alcohol. Grain alcohol has more fusel oil than the alcohol distilled from grapes. The fusel oil from grains consists mostly of amyl alcohol while that from grapes has more butyl alcohol in addition to many volatile fatty acid congeners. In the production of neutral spirits potato or grain alcohol is preferred over grape alcohol because of the lower cost of production. Highly purified neutral spirits with the fusel oil and impurities removed can still be identified according to the original source of the alcohol. Whether it is from grapes, corn, rye, wheat, potatoes, sugar cane, or is produced synthetically, the concentration of isotopes of carbon, hydrogen, and oxygen gives the purified alcohol distilled from each source a unique "fingerprint."