All About Coffee - William H. Ukers (best novel books to read .TXT) 📗
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The last three types were received by Dr. Cramer at Bangelan from Frère Gillet in the Belgian Congo, and were still under trial in Java in 1919.
Coffea Robusta
Emil Laurent, in 1898, discovered a species of coffee growing wild in Congo. This was taken up by a horticultural firm of Brussels, and cultivated for the market. This firm gave to the coffee the name Coffea robusta, although it had already been given the name of the discoverer, being known as Coffea Laurentii. The plant differs widely from both arabica and liberica, being considerably larger than either. The tree is umbrella-shaped, due to the fact that its branches are very long and bend toward the ground.
The leaves of robusta are much thinner than those of liberica, though not as thin as those of arabica. The tree, as a whole, is a very hardy variety and even bears blossoms when it is less than a year old. It blossoms throughout the entire year, the flowers having six-parted corollas. The drupes are smaller than those of liberica; but are much thinner skinned, so that the coffee bean is actually not any smaller. The drupes 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.
Coffee Estate in the Luquillo Mountains, Porto Rico Coffee Estate in the Luquillo Mountains, Porto Rico
COFFEE UNDER THE STARS AND STRIPES
Arno Viehoever, pharmacognosist in charge of the pharmacognosy laboratory of the Bureau of Chemistry, United States Department of Agriculture, has recently announced findings confirming Hartwich which appear to permit of differentiation between robusta, arabica, and liberica.[97] These are mainly the peculiar folding of the endosperm, showing quite generally a distinct hook in the case of the robusta coffee bean. The size of the embryo, and especially the relation of the rootlet to hypercotyl, will be found useful in the differentiation of the species Coffea arabica, liberica, and robusta (see cut, page 142).
Viehoever and Lepper carried on a series of cup tests of robusta, the results as to taste and flavor being distinctly favorable. They summarized their studies and tests as follows:
The time when coffee could be limited to beans obtained from plants of Coffea arabica and Coffea liberica has passed. Other species, with qualities which make them desirable, even in preference to the well reputed named ones, have been discovered and cultivated. Among them, the species or group of Coffea robusta has attained a great economic significance, and is grown in increasing amounts. While it has, as reports seem to indicate, not as yet been possible to obtain a strain that would be as desirable in flavor as the old "standard" Coffea arabica, well known as Java or "Fancy Java" coffee, its merits have been established.
The botanical origin is not quite cleared up, and the classification of the varieties belonging to the robusta group deserves further study. Anatomical means of differentiating robusta coffee from other species or groups, may be applied as distinctly helpful....
As is usual in most of the coffee species, caffein is present. The amount appears to be, on an average, somewhat larger (even exceeding 2.0 percent) than in the South American coffee species. In no instance, however, did the amount exceed the maximum limits observed in coffee in general....
Due to its rapid growth, early and prolific yield, resistance to coffee blight, and many other desirable qualities, Coffea robusta has established "its own". In the writers' judgment, robusta coffee deserves consideration and recognition.
Among the robusta varieties, Coffea canephora is a distinct species, well characterized by growth, leaves, and berries. The branches are slender and thinner than robusta; the leaves are dark green and narrower; the flowers are often tinged with red; the unripe berries are purple, the ripe berries bright red and oblong. The produce is like robusta, only the shape of the bean, somewhat narrower and more oblong, makes it look more attractive. Coffea canephora, like C. robusta, seems better fitted to higher altitudes.
Other canephora varieties include:
Madagascar, having small, slightly striped, bright red berries and small round beans;
Quillouensis, having dark green foliage and reddish brown young leaves; and,
Stenophylla Paris, with purplish young berries.
These last two named were under test at the Bangelan gardens in 1919.
Among other allied robusta species are:
Ugandæ:, whose produce is said to possess a better flavor than robusta;
Bukobensis, different from Ugandæ in the color of its berries, which are a dark red; and
Quillou, having bright red fruit, a copper-colored silver skin, three pounds of fruit producing one pound of market coffee. Some people prefer Quillou to robusta because of the difference in the taste of the roasted bean.
Some Interesting Hybrids
The most popular hybrid belongs to a crossing of liberica and arabica. Cramer states that the beans of this hybrid make an excellent coffee combining the strong taste of the liberica with the fine flavor of the old Government Java (arabica), adding:
The hybrids are not only of value to the roaster, but also to the planter. They are vigorous trees, practically free from leaf disease; they stand drought well and also heavy rains; they are not particular in regard to shade and upkeep; never fail to give a fair and often a rather heavy crop. The fruit ripens all the year around, and does not fall so easily as in the case of arabica.
Among other hybrids (many were still under trial in 1919) may be mentioned: Coffea excelsia x liberica; C. Abeokutæ x liberica; C. Dybowskii x excelsa; C. stenophylla x Abeokutæ; C. congensis x Ugandæ; C. Ugandæ x congensis; and C. robusta x Maragogipe.
There are many species of Coffea that stand quite apart from the main groups, arabica, robusta and liberica; but while some are of commercial value, most of them are interesting only from the scientific point of view. Among the latter may be mentioned: Coffea bengalensis, C. Perieri, C. mauritiana, C. macrocarpa, C. madagascariensis, and C. schumanniana.
M. Teyssonnier, of the experimental garden at Camayenne, French Guinea, West Africa, has produced a promising species of coffee known as affinis. It is a hybrid of C. stenophylla with a species of liberica.
Among other promising species recognized by Dr. Cramer are:
Coffea congensis, whose berry resembles that of C. arabica, when well prepared for the market being green or bluish; and
Coffea congensis var. Chalotii, probably a hybrid of C. congensis with C. canephora.
Caffein-free Coffee
Certain trees growing wild in the Comoro Islands and Madagascar are known as caffein-free coffee trees. Just whether they are entitled to this classification or not is a question. Some of the French and German investigators have reported coffee from these regions that was absolutely devoid of caffein. It was thought at first that they must represent an entirely new genus; but upon investigation, it was found that they belonged to the genus Coffea, to which all our common coffees belong. Professor Dubard, of the French National Museum and Colonial Garden, studied these trees botanically and classified them as C. Gallienii, C. Bonnieri, C. Mogeneti, and C. Augagneuri. The beans of berries from these trees were analyzed by Professor Bertrand and pronounced caffein-free; but Labroy, in writing of the same coffee, states that, while the bean is caffein-free, it contains a very bitter substance, cafamarine, which makes the infusion unfit for use. Dr. O.W. Willcox[98], in examining some specimens of wild coffee from Madagascar, found that the bean was not caffein-free; and though the caffein content was low, it was no lower than in some of the Porto Rican varieties.
Hartwich[99] reports that Hanausek found no caffein in C. mauritiana, C. humboltiana, C. Gallienii, C. Bonnerii, and C. Mogeneti.
Fungoid Disease of Coffee
The coffee tree, like every other living thing, has specific diseases and enemies, the most common of which are certain fungoid diseases where the mycelium of the fungus grows into the tissue and spots the leaves, eventually causing them to fall, thus robbing the plant of its only means of elaborating food. Its most deadly enemy in the insect world is a small insect of the lepidopterous variety, which is known as the coffee-leaf miner. It is closely related to the clothes moth and, like the moth, bores in its larval stage, feeding on the mesophyl of the leaves. This gives the leaves an appearance of being shriveled or dried by heat.
There are three principal diseases, due to fungi, from which the coffee plants suffer. The most common is known as the leaf-blight fungus, Pellicularia tokeroga, which is a slow-spreading disease, but one that causes great loss. Although the fungus does not produce spores, the leaves die and dry, and are blown away, carrying with them the dried mycelium of the fungus. This mycelium will start to grow as soon as it is supplied with a new moist coffee leaf to nourish it. The method of getting rid of this disease is to spray the trees in seasons of drought.
It was a fungoid disease known as the Hemileia vastatrix that attacked Ceylon's coffee industry in 1869, and eventually destroyed it. It is a microscopic fungus whose spores, carried by the wind, adhere to and germinate upon the leaves of the coffee tree[100].
Another common disease is known as the root disease, which eventually kills the tree by girdling it below the soil. It spreads slowly, but seems to be favored by collections of decaying matter around the base of the tree. Sometimes the digging of ditches around the roots is sufficient to protect it. The other common disease is due to Stilbium flavidum, and is found only in regions of great humidity. It affects both the leaf and the fruit and is known as the spot of leaf and fruit.
How the beans may be examined under the microscope, and what is revealed—Structure of the berry, the green, and the roasted bean—The coffee leaf disease under the microscope—Value of microscopic analysis in detecting adulteration
The microscopy of coffee is, on the whole, more important to the planter than to the consumer and the dealer; while, on the other hand, the microscopy is of paramount importance to the consumer and the dealer as furnishing the best means of determining whether the product offered is adulterated or not. Also, from this standpoint, the microscopy of the plant is less important than that of the bean.
Fig. 331. Coffee (Coffea arabica). I—Cross-section of berry, natural size; Pk, outer pericarp; Mk, endocarp; Ek, spermoderm; Sa, hard endosperm; Sp, soft endosperm. II—Longitudinal section of berry, natural size; Dis, bordered disk; Se, remains of sepals; Em, embryo. III—Embryo, enlarged; cot, cotyledon; rad, radicle. (Tschirch and Oesterle.)
The Fruit and the Bean
The fruit, as stated in chapter XV, consists of two parts, each one
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