COFFEE. The Coffee-Tree or Coffea Ara biro is an evergreen shrub, with oblong pulpy berries, which are at first of a bright red, but afterwards become purple. It is stated by Niebuhr to have been brought from Abyssinia to Yemen by the Arabs, from a country similar to their own plains and mountains. By that people it has for ages been cultivated in the hilly range of Jabal, in a healthy temperate climate, watered by frequent rains, and abound ing in wells and water-tanks. A combination of circumstances seems to favour the cultiva • tion of coffee in Arabia, which can hardly be attained elsewhere. Frequent rains, and a pure and cloudless sky causing an almost un interrupted flood of light, communicate an ex cessive stimulus to all the functions of vegeta tion, and are causes of the perfect elaboration of those delicate principles on which the aroma of the coffee is dependent.
The seed consists of much horny albumen and a peculiar principle or alkaloid, termed cafeine, which is identical with the active prin ciple of tea, theine, as well as with paraguaine, the alkaloid of the Paraguay Tea. The seed is used in a raw state in medicine ; but when roasted, it forms the well-known coffee of com merce. The coffee-plant begins to produce fruit when two or two and a half years old ; hut the quality of the seeds from young stems is not so good as that from stems four or five years old. The size and colour of the bean (as the inner part of the seed is called) vary considerably, those from the West Indies being larger than those from the East.
Much more depends upon the manner of roasting and making the coffee than upon the quality of the bean. The superiority of French coffee, in the preparation of which little or no Mocha coffee is used, proves this position. The taste of raw coffee is somewhat sweetish ; but the application of heat in the process of roasting produces important changes. The bean increases to nearly twice the original size, while it loses about a third of its weight : a powerful and agreeable odour is evolved, and a large quantity of empyreumatic oil, which appears in small drops on the surface, is formed along with a bitter principle, proba bly by an alteration in the cafeine and of the saccharine matter. The roasting should take place in a close revolving iron cylinder, over a clear but moderate fire, and should not be carried too far : when the beans have acquired a light chestnut colour, the roasting should be discontinued. The beans are then to be cooled quickly by being tossed up into the air, and the grinding, or rather rough pounding, should be performed in a covered mortar or mill. The drink should be prepared
from it as soon as possible, by infusion, which is preferable, unless some apparatus be em ployed by which a kind of decoction is made in a close vessel. About half an ounce of coffee powder should be used for every eight ounces (half a pint) of water. In Britain the roasting is generally carried too far; and the subsequent parts of the process, instead of being performed immediately, are often post poned for days or even weeks, by which the aroma is dissipated: when made, the liquid is generally deficient in strength and clearness. The employment of white of egg or fish-skin to clarify is decidedly objectionable: clearness is thus purchased, hut at the expense of the strength.
It ivas an endeavour to establish an improved mode of roasting coffee that led to the death of Mr. Dakin, of St. Paul's Churchyard, in 1848. His plan consisted in placing the coffee in a cylinder lined with silver, and in enclosing this cylinder within a cellular steam oven, or cylinder, patented by other parties. The heat attained within the oven was very great, and the metal of the oven was not sound enough to resist its action : an explo sion ensued, with a fatal result. The silver or silvered cylinder was an intended means of retaining the fine qualities of the coffee, with out acquiring any defective qualities during the roasting.
The addition of milk (which should always he hot) and of sugar heighten the nourishing qualities of coffee, and in the morning render it a more substantial article for breakfast. When taken after dinner to promote digestion, it should be without milk, and, where the pa late can be reconciled to it, without sugar.
The coffee-trade has been wholly created since the beginning of the eighteenth century. Nearly all the coffee which now comes to Eu rope is the produce of trees propagated from a single plant, which, having been raised from seed procured from Mocha in Arabia, by Van Hoorn, governor of Batavia, was sent by him to the Botanical Garden at Amsterdam, and the progeny of which was, in the year 1718, twentyyears after its reception from Java, sent to Surinam.
The coffee imported in 1849 amounted to the following quantities :— Of this quantity nearly 87,000,000 lbs. were brought from Ceylon alone.
The use of chicory in coffee has already been adverted to. [Cureouv.]