This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
The vanilla plant is indigenous to the hot and moist woods of eastern Mexico, and is cultivated by fastening shoots to trees just near the ground. The shoots soon strike root, begin to produce fruit in about three years, and bear for about thirty years. From Mexico the plant has been transported to the West Indies, several of the East Indian islands, Bourbon and Madagascar. It is a long, dark, shining bean, not smooth, but corrugated. When the green color of the fruit begins to change, and before it has become ripe, the beans or pods are gathered and prepared for the market. Sometimes they are steeped in hot water, or partly sun-dried, and then wrapped up in blankets until moisture exudes, when the process is repeated. This is supposed to cause fermentation in some portions of the fruit, and develop the aroma.
After treatment, the pods are packed into bundles of fifty, the bundles being sometimes enveloped in tin foil, and they are then ready for exportation. When the Spanish conquerors went to Mexico they found that vanilla was in common use by the natives for flavoring chocolate, and this alliance has met the approval of all succeeding years. One suggests the other. Bottlers have long used it to impart a rich yet delicate flavor to many of their gased beverages. When intelligently handled it vastly improves the finer grade of drinks. It is also used for other purposes in the factory, and is much esteemed for its general good qualities.
Although there are the Bourbon, Costa Rican and Venezuelan vanillas, as well as those of Brazil, Peru and Spain, the Mexican vanilla still ranks as the best. The Venezuelan has a flavor of the tonka bean. The odor of the tonka bean just referred to, as well as that of the mylilotus, or sweet clover, resembles vanilla somewhat, and is owing to the presence of coumarin, which these plants contain.
The vanilla beans are distinguished and assorted according to their size, and the thickness of their integuments. The finest quality attains a length of twelve inches, has a thin pericarp, and is rarely seen in the market. The varieties usually met with are from six to ten inches long, about one-third inch thick, and somewhat triangular but flattened. Vanilla is of dark-brown color, glossy, longitudinally wrinkled. The integuments of the fruit are leathery, of a brown color; the interior is filled with a blackish brown fragrant pulp, in which very numerous minute, black, flattish, ovate seeds are imbedded. The vanilla bean contains extractive, fixed oil, and crystals of vanillin; besides resin, sugar and gum, etc. The odor of vanilla is not due to a volatile oil, but to a cry stallizable principle called vanillin.
Now, as in the earlier period of its employment, it is used as a condiment or flavoring material, while in Europe it is frequently prescribed by physicians as an aromatic stimulant for nervous disorders, and for hysteria, diminution of the vital forces, etc. In flavoring chocolate it is ground up with the seed, but for beverages, confectionery and cookery, it is most generally employed in the form of an extract. Much of the extract is adulterated with tonka bean (a description of which appears on another page), and the cheaper kinds are made solely from that. One familiar with the peculiar and delicate odor of vanilla can detect any admixture of this kind by the smell.