The Manufacture of Chocolate and other Cacao Preparations. Paul Zipperer
wild it is generally isolated under the shadow of larger trees; when cultivated, the young plant is placed under the shelter of banana trees, and at a later period of its growth shelter is provided by the coral (called Erythrina corallodendron or Erythrina indica), further known as “Coffie-mama” among the Surinam Dutch and madre del cacao among the Spaniards. Yet this tree, like the Maniok, is said not to enjoy so long a life as the cacao plant, which sometimes reaches an age of forty years. On this account the Castilloa or also Caesalpina dashyracis have recently been recommended as a more lasting protection. The fact that it does not lose its leaves during the dry season (e.g. on Java, during the East Monsoon) is an additional advantage.
A cacao plantation requires a considerable area, in the proportion of 50 hectares for 20,000 trees. The quantity of fruit to be obtained from that number of trees, as an annual crop, would be worth from £ 1,200–1,300. In planting the seeds, they are set in rows that are from 8 to 10 m. apart, four or five seeds being planted within from 1 to 2 m, the shading trees being planted between the rows. Of each five seeds planted the greater number often fail to germinate, either in consequence of unfavourable weather or as the result of attacks by insects etc.; but if more than one plant grows, the weaker ones are pulled up. Until the plants are two or three years old, they are protected by a shed open at one side, and they are transplanted after they have attained a height of 3 ft. The chief enemies of tropical cultivation—weeds, aerial roots, insects, bacterial infection—have to be provided against continually, so as to prevent damage; accordingly if the ground be not moist enough, it should be systematically watered, and so drained if marshy, for the tree requires most careful nursing if it is to develop into a prolific fruit-bearing specimen. The seed germinates about fourteen days after being planted; but flowers are not produced till after 3 or 5 years. After the tree has once born fruit, which may occur at the end of the fourth year it often continues to do so for fifty years. The tree is most prolific when from twelve to thirty years old.
As in the case of all cultivated plants and domestic animals, the existence of which does not depend on the principal of natural selection, and among which life is not a continuous development of endurance in the face of adverse elements, the cacao tree has its peculiar diseases. Indeed, it would seem as though it were beset by all vermin extant. The reader may obtain some idea of the extent of the damage done to cacao plantations by such noxious agents, if he turns up the clear and exhaustive account published by the Imperial Biological Institute for Agriculture and Forestry (Germany).5 Unfortunately we have not space here to mention more than a few of the most frequently occurring and important diseases, such as the GUM DISEASE, which is especially destructive, gum formations in the wood tissue and bark of the tree eventually killing it. Next to be dreaded are the various fungus growths, cancers and cancer-like incrustations (“Krulloten”) and broom formations. It often happens that specii of beetle attack the tree, causing decay and rot to set in; such e.g. are the wood-borer, bark bug, and woodbeetle. Other parasites, again, do not destroy the whole tree, but are equally detrimental, as they also preclude all prospects of a harvest. Fruit rot and its like, fruit cancer, and cacao moths, are notorious in this connection. There are also several larger creatures which betray a preference for the nutritious fruit of the cacao tree, various species of rat, and the squirrel, which unite to make the planter’s life a burden.
d) Gathering and Fermentation.
The gathering of the fruit is effected by means of long rods, at the end of which is a semi-circular knife for cutting through the stalk. The fruits are then split in two, the beans separated from the surrounding pulp and spread out on screens to dry, or exposed to the sun on bamboo floors. Beans so prepared are described as unfermented.
In most lands where cacao is cultivated, another process is adopted, calculated to heighten the flavour of the fruit and develop its nutritious constituents. The newly gathered beans are first partially freed from the fruity substances always adhering, then piled up into heaps and covered with banana skins or cocoa-nut matting, in order that they may be shut off as far as possible from all atmospheric influence, and so left for some time, while the chemical processes of warming and fermentation are gradually consummating. This procedure is alternated with repeated exposures to the sun, according to the maturity and species of the cacao bean, and the prevailing weather conditions; though details as to the length of time and number of repetitions necessary to the production of a marketable article still await determination.6 It may be taken as a general rule that fermentation should proceed till the bean, or rather the cotyledon, has acquired the light brown colour characteristic of chocolate. This principle is nevertheless often violated, especially as loss of weight in the bean is often intimately connected with complete fermentation. Unsufficiently fermented varieties, but which were fully ripe when gathered, develop a violet colour during this process; it is possible for them to pass through what is known as “After fermentation” before reaching the factory. This is not so in the case of beans developing from unripe fruit, for obviously the valuable constituents of the cotyledon are here not prominent, and scarcely calculated to ferment properly. Such can be recognised by their betraying a bluish grey colour in the drying processes, and the soft and smooth structure which they then acquire. A normal progress of fermentation is indicated where the interior of the mass of beans registers, on the first morning after gathering, a temperature not exceeding 30–33° C, 35–38° on the second day, and on the third morning a temperature not exceeding 43° C. If the outer shells are marked, the heating has been too severe. In countries where the harvest season suffers from the periodical rains, drying over wooden fires7 is often resorted to. The value of many specimens is hereby greatly diminished when the roasting is carelessly managed, for the smoke must on no account be allowed to come into contact with the bean. Yet “Smoky” lots among the St. Thomas, Accra, and Kameroon sorts were formerly much more frequent in commerce than now, for the planter has learned to avoid this evil. After they have been fermented, the beans are washed, or trodden with the naked foot, in some countries, and so cleansed from the pulp remains still adhering. They are then allowed to dry in the open air, and packed into sacks; contact with metal or stone is strictly to be avoided, which as good conductors of heat and rapid cooling agents are most disadvantageous. Instead of piling the beans up in loose heaps, they may be fermented in “Tanks” made of wood, and where possible, provided with partitions. According to Kindt, cedar wood has been proved best for this purpose, because of its enormous resisting capacity. It used to be thought that in fermentation ensued a germination of the seed,8 as in the preparation of malt; but this idea has been proved erroneous. The contrary is rather the case, for the process almost kills the seed; and when the sensitiveness of the latter is taken into consideration, and also the fact that it only develops under the most favourable conditions, it must be allowed that the statement contains an obvious truth. Yet chemical change does take place in the fermentation of the seed; but as to its precise nature, owing to the lack of scientific research on the scene of operations, we are still unable to dogmatise. It would therefore be useless to discuss the manifold theories and speculations bearing on this point, and waste of time to discuss the various kinds of fermentation and the chemical processes therein involved. Yet it may almost be taken for granted, that the fresh-plucked bean contains a so-called glycoside9 which decomposes into grape sugar, into an equally amyloids colour stuff (the so-called cacao-red), and the nitrogeneous alkaloids Theobromine and Kaffein; a change probably incidental to the fermentation.10 The sugar might further split up into Alcohol and Carbonic Acid Gas, although this is by no means established.
Whilst we have lost our bearings as far as the chemical aspect of this process is concerned, we are much more firm in respect to the biological, thanks to researches which Dr. v. Preyers has conducted on the spot in Ceylon. Preyer’s11 experiments leave absolutely no room for objection, and it can safely be accepted that there are no bacteria present in fermentation, but a fungus-like growth rich in life, a kind of yeast by him called Saccharomyces Theobromae, and described in passing;12 facts which constitute the gist of his findings. He further establishes that the presence of bacteria often noticed is absolutely undesirable, and that better results are obtained when all life is energetically combated, and especially these bacteria. We should, then, be confronted with the same phenomenon in the preparation of cacao as are already met with in beer brewing, and the pressing of wine and which are still waited for in the preparing of tea and tobacco.
The kernel of the fresh bean,