英文科學(xué)讀本 第五冊(cè)·Lesson 13 Coffee

Lesson 13 Coffee

Coffee stands next to tea as a favorite and refreshing hot drink. It has a pleasant aroma and flavor of its own, and, when taken in moderation, is a most wholesome beverage. Its refreshing powers are best felt when one is weary and drowsy with sleep. It then acts as a slight stimulant, rousing to fresh activity, and overcoming the desire to sleep, as if by magic.

Like tea, the beverage is an infusion. It is made by pouring boiling water on the reddish-brown powdered coffee supplied by the grocer. The powder itself is obtained by grinding coffee-berries in a mill. These coffee-berries are found, on examination, to resemble small, oval beans, or kernels. They are of a darkbrown color, hard and somewhat brittle, for they break easily, and they have the same peculiar aroma and flavor as the powder and the prepared beverage itself. They are the fruit of a pretty evergreen tree which grows in the tropics.

The tree very much resembles the laurel, and, like it, has oblong, pointed leaves, of a bright, deep, glossy green. Being an evergreen, it keeps this bright, glossy foliage all through the year. In its natural or wild state it grows from 15 to 20 feet high, but under cultivation it is kept well cut, and is rarely allowed to exceed 8 feet in height.

It bears pretty white and rose-tinted flowers, not unlike those of the jessamine, which cluster in profusion round the branches, especially between the joints of the young twigs. Most of the flowers burst out at one time, and so thick and close are they, that the tree appears as though covered with snow, while the air for a considerable distance around is laden with their delicious fragrance.

When the flower falls off, which it does as rapidly as it comes, it leaves the fruit—a small, dark-red berry, not unlike a cherry. It consists of a soft, pulpy, or fleshy part outside, with two hard, oval bodies or kernels in the centre. These kernels are the coffee-berries which we use.

If we examine some specimens of the berries, we find that one side is rounded or convex, the other flat. In the fruit itself the two flat sides lie together, and each kernel is enclosed separately in a tough membrane or skin.

The coffee tree is a native of Abyssinia, where it may still be seen growing wild. As far back as the year 1454 it was introduced into Arabia, and it is now cultivated in nearly all the tropical countries of the world. It is grown most extensively in Brazil and in the East and West Indies.

The culture of the coffee tree is very simple, and, as a rule, it will flourish in high lands, which are unsuited to most other crops. It is a curious fact that plants grown in low damp situations give a greater yield, but the berries are of inferior quality; while those grown in hilly districts produce less, but the quality is better.

The trees do not begin to yield till they are two years old, and, as a rule, the crop is only a moderate one for the next two or three years. After this, however, they continue to bear for about eighteen or twenty years. Two pounds of berries is a good average yield for one tree annually.

As the berries ripen, the outer skin begins to shrivel up, and it is then time to gather them. In Arabia the berries are not plucked, but shaken from the tree. Of course only the ripe ones fall, and as they fall they are caught on cloths spread on the ground below. They are then laid in the sun and dried, after which they are placed in a trough, and made to pass between large revolving rollers. The pressure of the rollers breaks the husk into small pieces, which are winnowed away, and the berries, after being once more exposed to the drying action of the sun, are packed for exportation.

There are several, almost distinct varieties of the coffee-berry. The Arabian product is smaller than the rest, and more round than oval in shape. Its color, too (a sort of dark yellow), is peculiarly its own. The East Indian variety is larger than these, and also of a light color. The Brazil berries are the largest of all, and their color is a sort of greenish-gray.

It will be well at this point to carry our minds back for a moment to our lesson on tea. In it we learned that the raw leaves of the tea-plant possess neither aroma nor flavor, and that these properties are brought out by the roasting process.

It is just so with the coffee-berries. The raw berries have none of the fragrant odor and peculiar flavor with which we are familiar in coffee. These are only acquired after roasting.

The roasting process is a very delicate one, as the flavor and fragrance of the coffee depend wholly upon the care with which it is done. The berries are placed in a close iron cylinder, something like a barrel, which is fixed over a slow gentle fire, in such a way as to enable it to revolve constantly on a sort of pivot, the continual turning of the cylinder bringing all the berries in succession under the influence of the heat.