Coffee merchandising

The coffee tree, scientifically known as Coffea arabica, belongs to the two-leaved class of a large sub-kingdom of vegetable plants known as the Angiospermæ. Because it bears a flower arranged with its corolla all in one piece, forming a tube-shaped arrangement, it is further classified as Sympetalæ or Metachlamydeæ, which means that its petals are united.

Pursuing its classification still further, botanists place it in the order Rubiales and in the family Rubiaceæ or madder family, which also includes various herbs, and a few American plants, like the familiar bluets or Quaker ladies, and partridge berries. Quinine and ipecac are also members of this family.

Botany divides all families into smaller sections known as genera, and the coffee plant belongs to the genus Coffea. Under this genus are several sub-genera, and to the sub-genus Eucoffea belongs the common coffee, which the trade and the general public know best, Coffea arabica.

Coffea arabica is the original species indigenous to Abyssinia and Arabia, and for many years it was known as “Java” when it came from Java and “Mocha” when it came from Arabia. The Arabica seed transplanted to different soils and climates takes on local characteristics, and this gives us Bourbon, Mexican, Coban, Blue Mountain, Bogota, Bourbon Santos, etc., as the case may be.

There are many other species of coffee besides Arabica. They haven’t been described frequently, because, with one or two exceptions, they are commercially unimportant. Indeed, all botanists do not agree in their classification of the species and varieties of the Coffea genus. The systematic division of this interesting genus is far from finished; in fact, it may be said hardly to be begun.

Coffea arabica we know best because of the important role it plays in commerce.

Complete Classification of Coffee

The coffee plant most cultivated for its berries is, as already stated, Coffea arabica, which is found in tropical regions, although it can grow in temperate climates. Unlike most plants that grow best in the Tropics, it can stand low temperatures. It requires shade when it grows in hot, low-lying districts; but, when it grows on elevated land, it thrives without such protection. There are about eight recognized species of Coffea.

Coffea arabica is a shrub with evergreen leaves, and reaches a height of fourteen to twenty feet when fully grown. The shrub produces branches of two forms, known as uprights and laterals. When young, the plants have a main stem, the upright; which, however, eventually sends out side shoots, the laterals. The laterals may send out other laterals, known as secondary laterals, but no lateral can ever produce an upright. The laterals are produced in pairs and are opposite, the pairs being borne in whorls around the stem. The laterals are produced only when the joint of the upright, to which they are attached, is young; and, if they are broken off at that point, the upright has no power to reproduce them. The upright can produce new uprights also; but, if an upright is cut off, the laterals at that position tend to thicken up. This is very desirable, as the laterals produce the flowers, which seldom appear on the uprights. This fact is utilized in pruning the coffee tree, the uprights being cut back, the laterals then becoming more productive. Planters generally keep their trees pruned down to six to twelve feet.

The leaves are lanceolate, or lance-shaped, being borne in pairs opposite each other. They are three to six inches in length, thin, but of firm texture. They are very dark green on the upper surface, but much lighter underneath. The margin of the leaf is entire and wavy. In some tropical countries, the natives brew a coffee tea from the leaves of the coffee tree.

The coffee flowers are small, white, and very fragrant, having a delicate characteristic odor. They are borne in the axils of the leaves in clusters, and several crops are produced in one season, depending on the conditions of heat and moisture that prevail in the particular season. The different blossomings are classed as main blossoming and smaller blossomings. In semi-dry, high districts, as in Costa Rica or Guatemala, there is one blossoming season, about March, and flowers and fruit are not found together, as a rule, on the trees; but in lowland plantations, where rain is perennial, blooming and fruiting continue practically all the year, and ripe fruits, green fruits, open flowers, and flower buds are to be found at the same time on the same branchlet, not mixed together, but in the order indicated.

The flowers are tubular, the tube of the corolla dividing into five white segments. The number of petals is not at all constant, not even for flowers of the same tree.

While the usual color of the coffee flower is white, the fresh stamens and pistils may have a greenish tinge, and in some cultivated species the corolla is pale pink.

The size and condition of the flowers are entirely dependent on the weather. The flowers are sometimes very small, very fragrant, and very numerous; while at other times, when the weather is not hot and dry, they are very large, but not so numerous. Both these kinds “set fruit,” as it is called; but at times, especially in a very dry season, the trees bear flowers that are few in number, small, and imperfectly formed, the petals frequently being green instead of white. These flowers do not set fruit. The flowers that open on a dry sunny day show a greater yield of fruit than those which open on a wet day, as the first mentioned have a better chance of being pollinated by the insects and the wind.

After the flowers droop, there appear what are commercially known as coffee berries. Botanically speaking, “berry” is a misnomer. These little fruits are not berries, such as are well represented by the grape; but are drupes, which are better exemplified by the cherry and the peach. In the course of six or seven months, these coffee drupes develop into little red balls about the size of an ordinary cherry; but, instead of being round, they are somewhat ellipsoidal, having at the outer end a small umbilicus. The drupe of the coffee usually has two locules, each containing a little “stone” (the seed and its parchment covering), from which the coffee bean (seed) is obtained. Actually, then, the coffee berry is not a berry but a “drupe”; also, the coffee bean is not a “bean” but a seed.

Some few drupes contain three beans, while others, at the outer ends of the branches, contain only one round bean, known as the peaberry. The number of pickings corresponds to the different blossomings in the same season; and one tree of the species Arabica may yield from one to twelve pounds a year.

In countries like India and Africa, the birds and monkeys eat the ripe coffee berries. The so-called “monkey coffee” of India, according to Arnold, is the undigested coffee beans that passed through the alimentary canal of the animal.

The outer fleshy part or pulp surrounding the coffee beans is at present of no commercial importance. From the human standpoint, the pulp, or pericarp, as it is scientifically called, is rather an annoyance, as it must be removed in order to procure the beans. This is done in one of two ways. The first is known as the dry method, in which the entire fruit is allowed to dry, and is then cracked open. The second is called the wet method; the pericarp is removed by machine, and two wet, slimy seed packets are obtained. These packets, which look for all the world like seeds, are allowed to dry in such a way that fermentation takes place. This rids them of all the slime; and, after they are thoroughly dry, the endocarp, the so-called parchment covering, is easily cracked open and removed. At the same time that the parchment is removed, a thin silvery membrane, known scientifically as the spermoderm (which means seed skin), referred to in the trade as the silver skin, beneath the parchment, comes off too. There are always small fragments of this silver skin to be found in the groove of the coffee bean contained within the parchment packet.

We have said that the coffee tree yields from one to twelve pounds a year, but of course this varies with the individual tree and also with the region. In some countries the whole year’s yield is less than 200 pounds an acre, while there is on record a patch in Brazil which yields about seventeen pounds a tree, bringing the acre yield much higher.

The beans do not retain their vitality for planting for any considerable time; and, if they are thoroughly dried, or are kept for longer than three or four months, they are useless for that purpose. It takes the seed about six weeks to germinate and to appear above ground. Trees raised from seed begin to blossom in about three years, but a good crop cannot be expected of them for the first five or six years. Their usefulness, save in exceptional cases, is ended in about thirty years.

The coffee tree can be propagated other than by seeds. The upright branches may be used as slips, which, after taking root, will produce seed-bearing laterals. The laterals themselves cannot be used as slips. In Central America, the natives sometimes use coffee uprights for fences, and it is no uncommon sight to see the fence posts “growing.”

Thus far there are 12 recognized varieties of Arabica, as follows: Laurina, Murta, Menosperma, Mokka, Purpurescens, Variegata, Amarella, Bullata, Angustifolia, Erecta, Maragogipe, and Columnaris.

Two other species of coffee that have become better known in the trade are Liberica and Robusta. Liberica is a much larger and sturdier tree than Arabica, and sometimes reaches a height of thirty feet. Its leaves are twice as long, and the flowers are larger and borne in dense clusters. At any time during the season, the same tree may bear flowers, white or pinkish, and fragrant, or even green, together with fruits, some green, some ripe and of a brilliant red. The corolla has been known to have seven segments, though as a rule it has five. The fruits are large, round, and dull red; the pulps are not juicy, and are somewhat bitter. Unlike Coffea arabica, the ripened berries do not fall from the trees, and so the picking may be delayed at the planter’s convenience. The Liberica bean produces a drink which is classed as inferior to Arabica by trade experts.

The Robusta plant is larger than either Arabica or Liberica. The leaves of Robusta are much thinner than those of Liberica, though not so thin as those of Arabica. The tree, as a whole, is a very hardy variety, and bears blossoms even when it is less than a year old. It blossoms throughout the entire year, the flowers having six-parted corollas. The berries are smaller than those of Liberica, but are much thinner skinned; so that the coffee bean is actually not any smaller. They mature in ten months. Although the plants bear as early as the first year, the yield for the first two years is of no account, but by the fourth year the crop is large. Recently cup tests have established high merits in certain strains of Robusta. A variety of Robusta called Canephora has flowers tinged with red, its unripe berries are purple, and the bean narrower and more oblong than Robusta. It grows well in high altitudes. Among the allied Robusta species are Ugandæ and Quillou.

Experiments in coffee culture are constantly being made by well-known botanists, and some interesting hybrids have been produced, the most popular belonging to a crossing of Liberica and Arabica. Excelsa, an allied Liberica species, has also given much promise.

A species of coffee growing wild in the Comoro Islands and Madagascar has been found practically caffein-free. Certain Porto Rico coffees are also very low in caffein content.