The coffee-tree is native to Abyssinia, but is now grown in all tropical countries. It belongs to the genus Coffea, of which there are about twenty-two species. The seeds of berries of coffee-trees constitute the coffee of commerce. Each berry contains two seeds, with exception of maleberry, which is a single round seed. In their natural state they are almost tasteless; therefore color, shape, and size determine value. Formerly, coffee was cured by exposure to the sun; but on account of warm climate and sudden rainfalls, coffee was often injured. By the new method coffee is washed, and then dried by steam heat.
The stimulating property of coffee is due to the alkaloid caffeine, together with an essential oil. Like tea, it contains an astringent. Coffee is more stimulating than tea, although, weight for weight, tea contains about twice as much theine as coffee contains caffeine. The smaller proportion of tea used, accounts for the difference. A cup of coffee with breakfast, and a cup of tea with supper, serve as a mild stimulant for an adult, and form a valuable food adjunct, but should never be found in the dietary of a child or dyspeptic. Coffee taken in moderation quickens action of the heart, acts directly upon the nervous system, and assists gastric digestion. Fatigue of body and mind are much lessened by moderate use of coffee; severe exposure to cold can be better endured by the coffee drinker. In times of war, coffee has proved more valuable than alcoholic stimulants to keep up the enduring power of soldiers. Coffee acts as an antidote for opium and alcoholic poisoning. Tea and coffee are much more readily absorbed when taken on an empty stomach; therefore this should be avoided except when used for medicinal purposes. Coffee must be taken in moderation; its excessive use means palpitation of the heart, tremor, insomnia, and nervous prostration.
Buying of Coffee. Coffee should be bought for family use in small quantities, freshly roasted and ground; or, if one has a coffee-mill, it may be ground at home as needed. After being ground, unless kept air tight, it quickly deteriorates. If not bought in air-tight cans, with tight-fitting cover, or glass jar, it should be emptied into canister as soon as brought from grocer’s.
Coffee may be served as filtered coffee, infusion of coffee, or decoction of coffee. Commonly speaking, boiled coffee is preferred, and is more economical for the consumer. Coffee is ground fine, coarse, and medium; and the grinding depends on the way in which it is to be made. For filtered coffee have it finely ground; for boiled, coarse or medium.