Coffee, as ordinarily prepared for beverage, contains only two-sevenths of the nitrogenous or nutritive matter of the fresh bean, but two-thirds of the roasted, and the mineral ingredients are all present.
M. Lebreton (“Agriculteur praticien”) has estimated the loss of weight of coffee in roasting at 18 to 20 per cent. in Porto Rico, Rio, and Martinique coffee; and at 16 to 18 per cent. in Malabar, Bourbon, Ceylon, and Guadaloupe coffees; while in Mocha coffee it amounts to only 14 or 16. The loss of weight depends upon the time of roasting and the degree of heat. Damp or damaged coffee loses more than dry sound coffee. He considers that these substances have the capability of rendering the individual insensible of a certain deficiency of food, in virtue of their retardation of the assimilative process. He thinks it probable, likewise, that these substances have a direct nutritive value, especially coffee as drank by the Turks and Arabs with the grounds.
Professor Lehmann considers that the singular preference for one or other of these beverages by particular nations, as well as the Eastern custom of drinking coffee with the grounds, are not accidental, but have some deeper reason. This reason, he thinks, is to be found in the different effects of the coffee, tea, &c., and the various requirements of the nations by whom they are used, and instances the use of tea by the English, and of coffee by the Germans and French, as in accordance with this view. The diet of the former affords a larger supply of plastic material than that of the latter people; and while, consequently, the retardation of the assimilative process is an important influence for the German, the proportionately greater nervous stimulus caused by tea is more desirable for the former. The use of coffee with its grounds has its analogue in the use of tea mixed with meal, milk, and butter among the Mongols, and other inhabitants of the Central Asiatic steppes.
M. Payen, from elaborate experiments, shows that coffee slightly roasted is that which contains the maximum of aroma, weight, and nutrition. He declares coffee to be very nourishing, as it contains a large quantity of nitrogen, three times as much nutriment as tea, and more than twice the nourishment of soup. Chicory contains only half the nutriment of coffee.
SECTION VI.
COFFEE-LEAF TEA, &c.
Attention was some time ago drawn to the subject of coffee-leaf tea, which is used in Sumatra and other parts of the East, and a good deal of discussion ensued upon the matter, after the leaves were shown for the purpose at the International Exhibition of 1851. An infusion of roasted coffee-leaves is pronounced by those who have had an opportunity of tasting it, as superior to Bohea, and by some enthusiastic admirers is said to rival the flavour of the most delicate Pekoe. That an infusion of roasted coffee-leaves should imitate the flavour of tea is not to be wondered at, as the leaves of both shrubs contain in the main the same leading principles, more particularly theine or caffeine. There is no doubt that coffee-leaf tea would command a sale in England, but the question is how much could be collected to make it profitable, and it involves the necessity of apparatus and skilled labour for parching the leaves.
Coffee-leaves are not quite so thick as those of Vallambrosa, and a Malabar coolie would not in one day collect enough to pay the expense of picking, drying, packing, cartage, warehouse rent, freight, and other charges.
Moreover, no planter of any experience would think of stripping his trees of their breathing organs, and the quantity that might be collected from the suckers and prunings, &c., would never give more than a few bales, even on large plantations. Even were the fallen leaves supposed to be available, their removal would be as detrimental as the practice of raking away withered leaves in plantations, or the application of the sugar-cane trash to the purposes of fuel.
The husks, pulp, and parchment in South America, the West Indies, Ceylon, and the other Indian islands, are regarded as mere waste, and thrown away. In Arabia and some parts of the East, however, this refuse is utilised, as the “miserables,” or husks of the cocoa-seed (Theobroma cacao), are in Ireland and the Continent. With it is prepared the famous kisher, or “Café à la Sultane,” a light-coloured, bright infusion, which has all the agreeable flavour of coffee, with little of its strength and none of its bitterness; this is partaken of by the humbler classes in incredible quantities.
When quite dry and ripe these husks are bruised, and roasted in an earthen vessel over a charcoal fire, not as coffee usually is, but only until it assumes a light-brown colour. While hot it is thrown into a pot of boiling water, with a small proportion of the pellicle or parchment skin; all is boiled together for a few minutes, and then served hot and strong, but without sugar. Sometimes a drop of essence of amber is put into each cup; or cloves, aniseed, or cardamoms are boiled with it.