Up to the end of the eighteenth century the manufacture of chocolate was carried on entirely by hand, a method at once laborious and inefficient. The workman used to kneel down on the ground, and crush the beans in iron mortars. It was not until 1732105that Buisson introduced the use of a bench and so rendered that inconvenient and unwholesome practice unnecessary. Even to-day, the Chinese cooks on the Philippine islands carry their chocolate “Factory” about with them, in which the trestle is essential. It further comprises a small marble mortar and warmed pestle, and by means of these utensils and implements the hulled beans are pounded, and the triturated mass so obtained spread out. It is then flavoured with sugar and spices. With that exception, hand labour in the chocolate manufacture has since the year 1778 been entirely displaced by machinery, when Doret exhibited the first specimen before the medical faculty of Paris. According to Belfort de la Roque,106a Genoese named Bozelly had already constructed a mill by means of which he was able to prepare from six to seven hundred pounds of chocolate daily, comparing favourably with the thirty pound output yielded by hand labour.Pelletier107, in 1819, describes a machine for the mechanical preparation of chocolate of his own construction, capable of doing the work of seven men. The machines used in the chocolate manufacture have since that time been repeatedly improved and re-constructed, although always with this one end in view, namely to obtain a fine even cacao mass, and afterwards mix it as thoroughly as possible with the other ingredients employed.
The first machines of the modern type were constructed by the Parisian mechanic George Hermann (1801-1883) in the year 1830, to which inventor we are indebted for the principle of fine grinding with varying velocities, on which manufacture of chocolate is based to-day. There is at the present time a rather large circle of manufacturers engaged in the putting together of special machines for the preparation of cacao and cacao products, chocolate apart.
Whether chocolate manufacture be carried out on a large or small scale, it always involves the subjecting of the cacao bean to a regularly succeeding series of operations, before the resulting product known as “Chocolate” (in the strict commercial sense of the term) can be obtained.
The respective operations succeed each other as follows:
I.Preparation of the Beans.
1.Storing,cleansingandsortingof raw beans.2.Roastingthe cleansed beans.3.Crushing,shellingandcleansingthe roasted bean (removing the radicles etc.)4.Mixingdifferent kinds of beans.
1.Storing,cleansingandsortingof raw beans.
2.Roastingthe cleansed beans.
3.Crushing,shellingandcleansingthe roasted bean (removing the radicles etc.)
4.Mixingdifferent kinds of beans.
II.Production of the Cacao Mass.
5.Grindingthe beans till they yield a homogenous paste on heating.6.Mixtureof the liquefied cacao mass with sugar, spices, etc.7.Triturationby rollers.
5.Grindingthe beans till they yield a homogenous paste on heating.
6.Mixtureof the liquefied cacao mass with sugar, spices, etc.
7.Triturationby rollers.
III.Preparationof the resultingChocolate.
8.Extractionofair,divisionandmoulding.9.Cooling.10.Packingandstoring.
8.Extractionofair,divisionandmoulding.
9.Cooling.
10.Packingandstoring.
This represents the general course of manufacture, which we will now proceed to describe in more detail, following the headings given above.
Right up to the moment when they are to be used in the manufacture, the raw cacao beans must be kept as originally packed, and stored in an airy sun-lit room; although if they have accumulated moisture during transport or sustained any manner of damage in harvesting, they should then be emptied out of the sacks, spread out over the floor of such a room as above described, and dried as effectively as possible. It has also been recommended that such beans be washed with a dilute solution of caustic potash (1 in 5000), and afterwards dried rapidly.
Unfermented beans, those damaged in the harvest, and those which have received no proper fermentation, develop a greyish white colour with occasional tints of violet and an unpleasant, bitter herbal flavour, properties which unfortunately penetrate to the resulting cacao products. Attempts have been made to meet this evil with a so-called “Secondary Fermenting Gordian108proposes in this connection that the beans be filled in water-butts, and steeped in warm water for at least 48 hours (so that obviously the butts must be kept in a warm room), at the expiration of which time it can be poured off, and the beans dried in a chamber heated to a temperature of between forty and fifty degrees centigrade. There is said to ensue an appreciable improvement as to flavour and colour, when this process is carried out.
The magazines in which cacao beans are stored have sometimes an unwelcome visitor, to wit, a grub which according to W. Hauswaldt109happens to attack just the best kinds of Caracas and Trinidad. As eggs of the grub have on several occasions been found on the interior of the still unshelled bean, we may assume that they were deposited by a butterfly (species unknown, but possibly Ephestia cahiriteller, cf. von Faber loc. cit. page 335) either before or immediately after fermentation, and no later. Sometimes these grubs appear on the surface of the sacks, which they overspread in a few days. Removal of the infected packages, opening the sacks, and exposure to the sun, as well as a thorough cleansing of the storehouses, is attended with a qualified amount of success.The best plan is to destroy the moths during their period of activity in the summer months June, July, and August.
According to Hauswaldt, Stollwerck110and G. Reinhardt111, this can be effected by placing in the store rooms large, shallow basins of water, near which burning petroleum lamps are introduced on the approach of dusk, favourably placed on a pile of bricks and stone, so that they clearly illuminate the reflecting water. The moths assemble round the light en masse and either perish in the water or flame, a fate which sometimes overtakes even the larvae, for they display the same fatal attraction for any light, real or apparent. The water must be changed every day, as otherwise the wing-dust collecting on its surface affords a means of escape to the insects coming later. As the weather becomes cooler, the doors and windows of the store-rooms should be left open, so that when frost sets in, the rest of the maggots may be destroyed.
The cleansing and sorting of the raw cacao bean is the most important factor in the manufacture of chocolate, and yield a manifold return, for inferior and cheaper kinds of bean which have passed through these processes can be advantageously mixed with finer varieties. The chief object of cleansing and sorting is the removal of foreign bodies and such chance admixtures as sand, pebbles, and fragments of sacking, which are liable to damage the stones used in grinding at a later stage of the preparation, or communicate an unnatural and disagreeable smell to the subsequent roast products. These admixtures are so multiform and various that they cannot be removed solely by the aid of machinery, but must be finally picked out by hand. Mechanical appliances are limited to the removal of pebbles, dust, and possible fragments of iron, after which preliminary cleaning the beans are thrown on straps, where they can be picked by hand. The collector of these foreign bodies would find himself with a rather interesting stock at the end of a few years, as Wilhelm Schütte-Felsche points out.
The cleansing of the raw beans was formerly carried out in so-called roller casks, placed horizontally, and revolving round an axle fitted in the floor, whence it passed upward, cutting them slantwise. In this apparatus the beans were rolled and vigorously rubbed together, and afterwards the hand-picking succeeded. More recently,the roller casks have been displaced by rotary cylindrical sieves, driven by motor power.
Such a machine is illustrated in fig. 12. The beans are lifted to a rotatory cylindrical sieve by means of an elevator, where they are freed from dust and dirt; in other sections of the sieve fragments of blossom, sacking, or cloth are isolated, whilst occasional splinters of iron are removed by a large magnet. So prepared, the beans are cast on running belts, and here the hand-picking above-mentioned is carried out.
Fig. 13 shows a cleansing machine for the same purpose, which has recently become rather popular. Here the dust passing from the sieve is sucked up into a dust chamber, by means of an exhauster, whilst pebbles, blossom fragments, and small beans are separately isolated. The cleansed beans pass likewise under magnetic influence, which removes traces of iron, and finally succeed to the running belting.
Often the beans are introduced into an extensive brushing machine before roasting, to cleanse them from dirt etc. These are generally found in such factories as have circular and cylinder roasters with direct heating apparatus. Fig. 13 a shows such a brushing machine for cacao beans.
The cleansed and sorted beans are now subjected to a high temperature, that is to say, they are now roasted. This roasting answers many purposes;
1. The aroma and flavour of the bean is so developed.2. The starch granules are gelatinised.3. The herbal constituents are so transformed that the flavour of the beans becomes milder; a distinct improvement.4. In the consequent drying, the shells are rendered brittle, and more easily removeable.5. The beans themselves can afterwards be better ground.
1. The aroma and flavour of the bean is so developed.
2. The starch granules are gelatinised.
3. The herbal constituents are so transformed that the flavour of the beans becomes milder; a distinct improvement.
4. In the consequent drying, the shells are rendered brittle, and more easily removeable.
5. The beans themselves can afterwards be better ground.
The roasting of the cacao bean does not demand so high a temperature as that of coffee, to effect the above chemical and physical changes. Experience has shown that the best temperature lies between 130-140 ° C., though deviations from this standard have recently become frequent and considerable, according to the uses for which the cacaos are intended, and roasting has sometimes taken place at a temperature even as low as 100 ° C.
Fig. 12.
Fig. 12.
The process of roasting can be carried out in the roasting drum or machine in a variety of ways, as:
1. Direct roasting over a coal fire,
2. Passing of a hot-air stream over the beans,
Fig. 13.
Fig. 13.
3. Roasting by means of gas, with compressed air, as far assources of heatare concerned; and as regardsshape of the drum, it is to be noted that the cylindrical are most in use.The separation of the shells from the kernel was still effected at the beginning of the present century by stirring the beans in water and so detaching the inner coating of the seeds, the method adopted by Weisched (Mitscherlich page 112). Not till this stage had been reached were they subjected to a strong heat, causing the shells to spring off.
This method has at the present time only historical interest, for the so-called roasting drums, as used in the preparation of coffee, are now universal.
Fig. 13a.
Fig. 13a.
Roasting must be attended with the greatest care, in order that it may neither be too thorough nor insufficient. It is a great mistake to think that the roasting machine can be handed over to the care of any apprentice. That nicety of roasting which corresponds to the variety and its subsequent utilisation constitutes the qualitative basis of the chocolate manufactured later. It is impossible for even the best chocolate maker to retrieve what has been spoilt in this important preliminary operation, wherefore a skilled workman, endowed with a keen sense of taste and smell, is always to be seen at the roasting machine.
It has already been attempted to provide a means of security against over-burning by the construction of the so-called safety-roaster, about which will be spoken later.
Overroasting is immediately indicated by a disagreeable empyreumatic odour (resembling that of roasted coffee); the huskschar and the kernels crumble, also betraying a charring on the outside. There is a correspondingly increasing keenness of flavour, and a transference of theobromine from the kernel to the husks (cf. page 65). From the destructive distillation of the cacao fat arises that volatile and pungent acroleine which is the principal cause of the empyreuma of the over-roasted bean.
Fig. 14.
Fig. 14.
The following general precautions in roasting cacao are worthy of note; 1. the beans should not remain too long in the roasting drum; 2. they should be kept on the stir, for which reason the apparatus is made revolvable on its axles; 3. the heat applied should be carefully regulated; and 4. to guard against a loss of aroma, the roasted beans should be cooled as rapidly as possible.
As the cacao must be more or less roasted according to its quality and ultimate destination, which entails the acquisition of considerable empirical knowledge on the part of the workman entrustedwith this process, it would be neither advisable nor practicable to annex definite instructions as to time and temperature requirements.
In the following we describe a machine which is to be found in most factories and which corresponds to all the demands of technique. From its heating system, it belongs to the class of hot-air current roasters—direct coal fire assisting—and in shape to the cylindrical roasters.
Fig. 14 a.
Fig. 14 a.
This machine is illustrated in fig. 14 and shown in section in figs. 14 a and 14 b. To prevent loss of heat by radiation, to save fuel, and preclude possibilities of danger from fire, the whole installation is walled in. Driving shafts occur at the back of the machine, and the charging apparatus is introduced in front. A furnace lies directly under the drum, whilst on either side are chambers accessible to currents of fresh air, which are provided with heating tubes and which admit of a regulation of the air supply. They are shut off from connection with the gases from the fire, so that only the fresh air heated here can penetrate to the roasting products in the chargeddrum. There are winnowing shovels fitted in this, calculated to keep the beans in motion and facilitate the access of air. When the hopper is closed, the gases arising from the roast product can be led off by an annexed outlet pipe, and thereupon condensed and the resulting liquid drained off at the foot of the machine. For the attainment of the proper degree of roasting, as well as for controlling the whole process, there is a sampler to every machine. The drum is emptied whilst in motion, its door-like front being turned aside and the roasted beans transferred by the winnowing shovels before mentioned to trolleys wheeled underneath.
Fig. 14 b.
Fig. 14 b.
The loss of heat by radiation is very insignificant, as the machine is completely walled in. Any kind of fuel may be used. Since the stoking as well as the removal of soot takes place at the front, several of these roasters can be set up side by side. It is a great advantage of this installation, that by removal of the front of the drum its interior is laid quite open, admitting of a thorough overhaulingwhich is attended with every disadvantage for the flavour of subsequent roasting lots.
The machine here described is constructed in varying sizes, with an outside capacity of four hundred kilograms.
As already mentioned the so-called safety-roaster offers a certain security against the burning of the beans as the roasting boiler is lifted out of the fire by means of an automatically working safety regulator. Figs. 15 a and b show a spherical roaster open and closed.
Fig. 15 a.
Fig. 15 a.
The principal of construction is founded on the fact that each roasting is connected with a loss of weight and it is logical that the same quality of beans always yields the same loss of weight at a certain degree of roasting. On an average cacao yields a loss of 6-7 %. According to this, the loss of weight which can at first be empirically ascertained, for example by a new kind of bean, can be calculated and can be indicated on a regulator, on the principle of the Roman scale. When the beans have lost the weight in question thecounterpoise of the regulator raises the axle of the roasting sphere by means of which the working of the whole machine is set in motion.
There is no exception to the rule that only beans of one and the same kind should be roasted and broken up together, as thickness or thinness of the shells determines to a large extent the time required for roasting, and also an even size of bean is necessary to the smooth operation of the breaking machine. The husks of the roasted cacao bean are hygroscopic, and consequently the roasted unshelled beans contain more moisture after having been kept for a time, than they do in the raw state; but the drier the bean is, the easier it shells. The cacao is therefore to be worked up as quickly as possible, or at least kept in well covered metal boxes till further treatment can be proceeded with.
Fig. 15 b.
Fig. 15 b.
As sources of heat we find direct and indirect stoking with house coal and coal gas, and besides these, for the installations of larger factories Dowson gas is especially suitable, as it does notinvolve too high a temperature, and the outlay is not so great as when coal-gas is used.
Fig. 16.
Fig. 16.
The roasting machine in fig. 16 for Dowson or coal gas belongs to the class of roasters with direct firing. It corresponds to the one diagrammed in Fig. 15 as regards charging and emptying. Here also the front wall of the drum can be removed, and the interior consequently laid completely open. The transmission of gas is effected at an air pressure of one atmosphere, for the attainment of which an air pump is fitted up in the vicinity, capable of feeding four machines at the same time. The drum holds about 150 kilos.It goes without saying that the regulating of the requisite heat is in this instance of the utmost ease and nicety. Another preponderating advantage of this machine as compared with those heated with coke or ordinary coal is its clean operation and the extraordinary speed with which it can be both started and stopped. Form 3-4 cbm. of coal gas are needed for 100 kilos of beans, whilst for Dowson gas, which has not such a high heating value, much larger quantities are required, and consequently a stronger framework becomes necessary, though here no air pumps need be put in operation.
Fig. 17.
Fig. 17.
Steam roasting apparatus have not proved particularly successful, as has been evident in all experiments hitherto made with them, and steam agency does not appear to be suitable for the cacao bean, it admitting of no thorough and at the same time even roasting.
Yet on the other hand the hot air-current roasters described enjoy an ever increasing popularity, partly because they are heated indirectly, and again because they appreciably diminish the time taken up in the actual process, which in other cases approaches to as much as thirty or forty minutes, without exposing the beans to the danger of burning or getting charred.
As just stated, the beans should be passed on to the next process as speedily as possible, yet on the other hand be completelycooled off, so as to loosen their shells before they arrive in the breaking machine. There are also special constructions for this cooling. If the roasting drums are fitted up directly on the ground, it is effected by disposing the beans issuing from these machines in wide baskets or sieves, and letting them cool there before bringing them to the next process. Should they be situated at a sufficient height, the beans can be slowly transferred down a shoot connected with the rooms below, where crushing mills await them, and cooled on the journey by a play of fresh air currents.
Very much to the purpose and well adapted as regards most of the requisite conditions, are the cooling trucks with exhaust apparatus shown in fig. 17.
These trucks are fitted with perforated false bottoms and with sliding shutters at the side. After the contents of the roasting machine have been discharged into the trucks, these are wheeled over to the exhaust apparatus easily recognisable in the diagram, where the cacao is so far cooled that subsequent “after-roasting” is impossible, whilst the gases given off are conducted by the ventilator. This exhaust chamber can be made to work from both sides.
Up to ten years ago, the crushing and shelling of cacao beans had not been so far perfected as to effect the complete separation of husk and radicle from all particles of kernel, or to prevent loss by isolating and collecting the minute particles of kernel, which are drawn up through the exhaust apparatus in conjunction with the lightest of the cacao shells. Yet the requirements demanded of a satisfactory machine advanced to such an extent that not only cacao nibs free from shell were postulated—an end scarcely hard to attain—but shells free from cacao nibs were made a further essential. A machine which performs both these objects not only works excellently, but is also economical. For a solution of this problem the Association of German Chocolate Manufacturers, which is specially interested in all that concerns the chocolate industry, offered a prize years ago; the firm of J. M. Lehmann were the first to construct a machine answering every call made on it to perfection.
Fig. 18 illustrates a crushing and cleansing machine averaging an output of 2500-3000 kilos, of the latest and most modern type.
Fig. 18.
Fig. 18.
The beans are first broken into smaller pieces in all machines now employed as crushing, shelling or cleansing apparatus,and the one at present under consideration provides no exception. An air-current is made to play on these fragments, which finally isolates and transfers the loosened shells to another part of the apparatus. The cacao next succeeds to a crusher of regular capacity lodged in the upper part of the machine, being despatched on an elevator. The fragments fall into a cylindrical sieve, dust being detached in the first compartment, whilst the meshes of subsequent compartments gradually increase in size and sort the products therein transmitted in corresponding sizes. There is a groove traversed by air-currents—proceeding from a ventilator—immediately under each compartment. This current of air can be regulated, i. e. made weaker for lighter and stronger for heavier fragments, and there is a ventilator for every compartment to make this regulation of the easiest, and in this way shells of equal size but specifically lighter than, the cacao fragments are most efficaciously separated. Contrasting with the older type of machine, it works almost noiselessly, all shakings of grooves and sieves being entirely avoided; in addition to which there is a perfect exclusion of dust, when the shells are transferred into the dust-removing chamber. A further advantage is that there is no wearing out of the machine, except as regards the direct crushing apparatus, which occasionally need renewing.
The dust particles before mentioned, which possibly comprise as much as one half of the cacao fragments, require a special kind of working up, ondifferent machines, before the cacao still contained therein can be obtained. It is a fact obvious and apparent, that the smaller the fragments of shell mixed with this crushed cacao, the more difficult will be their separation, a fact of equal importance to technical and analytical science, and the more scrupulously this process is to be carried out, the greater the lavishment on sieves and ventilating compartments entailed.
To effect this operation on the breaking machine is seriously to overtask the latter, and defeats its own end, as experiments carried out in the Chocolate factory of Schütte-Felsche have proved, inasmuch as it leads very easily to mixing of the products which are to be kept separate.
Fig. 19 shows such a machine for the cleansing of this so-called cacao “dust
The particles are raised to a large flat sieve by means of an elevator, again sorted in different sizes, and submitted to air currents of corresponding strength. The quantity obtained variesaccording to the variety of cacao, though in some cases it may amount to 50 or 54 percent. What remains after this process is absolutely worthless and can only be considered as refuse, at least as far as the chocolate manufacturer is concerned.
Fig. 19.
Fig. 19.
It has become necessary in modern manufacture that iron fragments occurring in the machine not only be separated by distinct magnetic fields in the respective machines, but that this also be effected in a machine specially constructed for the purpose. Fig. 20 illustrates such an electromagnetic apparatus. The advantages of this system are that it avoids magnets limited in strength,and by the functioning of strong electro-magnets perfect cleansing even in the case of the largest output, as well as machines of the most simple construction, can be guaranteed.
We submit the following description of the machine and its method of working.
Fig. 20.
Fig. 20.
The machine contains a hopper with sloping groove to obtain an even introduction of the beans to be cleansed. At the end of this there is an electro-magnet roller, consisting of a non-magnetised mantle and a magnetic compartment round which it turns.
After traversing the sloping groove, the beans succeed to the roller, meeting it at a tangent. As soon as they reach the field of magnetism, all iron fragments are appropriated by the revolving mantle, whilst the beans themselves do not come into contact with this, but pass directly underneath. The iron fragments are disposed of separately, and outside the magnetising area.
It is of prime importance in the preparation of chocolate and more particularly of cocoa powder (easily soluble cacao), that the crushed material proceeding from the crushing machine should undergo a further purification, with a view to separating, and removing the hard radicles. These constitute the gritty sediment of insufficiently prepared cacao powder, when dissolved. J. M. Lehmann effects the complete removal of the radicle by means of his machine D. R. G. M. No. 24,989 (Fig. 21).
Fig. 21.
Fig. 21.
Here the finer siftings from the crusher are transferred to the controlling feeder, under which a small ventilator occurs, which provides for the removal of any still remaining portions of husk. Cacao and radicle descend to a shaking sieve, the finer particles passing through its meshes, whilst the larger grains fall into a pocket attached to the end, as cleansed product. The former fragments now succeed to a cylinder, having its inner surface punched with small cavities (fig. 22) and while the cacao particles remain in thosecavities during the rotation of the cylinder, the radicles of more elongated form are caught up by a special separator (1) and so prevented from being carried round with the rest. The cacao particles are then made to fall into a trough (3) by a brush (2) working against the cylinder, and subsequently urged forward by a conveyor (4). That process is enacted all along the cylinder, so that finally cacao and radicle issue from the machine completely separated.
Fig. 22.
Fig. 22.
The advantages, economical and otherwise, attending the use of the above breaking and cleansing machines become apparent when the following figures, registering results obtained in several experiments, are considered. Formerly the loss experienced in sorting, roasting, crushing and hulling averaged about 30 % of the total beans, but now the employment of the above machines shows the following satisfactory improvements.
The loss of 823 kg Machala beans, unroasted, amounted to a total:
a) in picking3·6kgb) " roasting63·5"c) " shelling61"d) " dust34"162·1 kg or 20%,
without taking into account the application of the waste; 2267 kg of St. Thomé raw cacao lost:
a) in picking5kgb) " roasting170"c) " shelling152"d) " dust79"406 kg or 20%.
According to these data the use of these machines admits of a saving of about 10 percent more material than in former work.
In connection with these particulars it is also of interest to consider the qualitative and quantitative composition of the various waste products of the manufacture. Filsinger112has at the instance of the Association of German Chocolate manufacturers, examined a mixture of 50 pounds of large Machala beans with an equal quantity of small beans, after passing it through a shelling machine of the most modern construction, and he thus obtained:
70poundsoflarge kernels,9·2""medium kernels,0·8""radicles,10""husk (outer woody shell),4""cacao waste,6""other loss,
The 4 pounds of cacao waste yielded by further sifting:
a) kernelI.sort250grammes,II."50"III."220"IV."25"b) huskI."185"II."55"III."370"IV."80"c) cacao dust725"d) waste30"e) loss10"2000 grammes.
Chemical analysis of these portions gave the following results:
PercentagesAshSandFatFibre1131. Husk 10% of the raw cacao11·151·904·5021·362. Cacao waste 4% of the raw cacao4·800·3515·4016·313. Seed shells I. sort ;0·37% of the raw cacao6·70—21·6410·294. Seed shells II. sort 0·11% of the raw cacao7·10—18·398·755. Seed shells III. sort 0·74% of the raw cacao7·20—15·7612·166. Seed shells IV. sort 0·16% of the raw cacao7·80—16·4012·747. Cacao dust 1·45% of the raw cacao11·75—22·068·408. Waste 0·06% of the raw cacao7·05—20·449·81
From these data it is evident that there is a great difference between the chemical composition of the so called cacao waste and that of the exterior ligneous shells. From the large amount of fat present in the former material it might be regarded, in the full sense of the term, as a cacao constituent and, for that reason, its presence in cacao preparations should not be objected to, while the husk containing as much as 20 percent of woody fibre cannot be considered a cacao constituent in the same sense.
Stress has already been laid on the variations in taste incidental to different species of bean. It has further to be noted that they develop a milder and more aromatic flavour according as they have been more properly fermented, and in contrary instances possess an astringent and even acid taste. It therefore becomes an aim of the manufacturer so to improve the flavour of inferior varieties by mixing with the finer as to produce a resultant cacao giving perfect satisfaction to every taste. Nevertheless the general rule still holds good that for the preparation of the finest qualities of chocolate only the better sorts of bean (as Caracas, Ariba, Puerto Cabello etc.) should be employed. For inferior and less expensive ware other varieties of bean suffice, the mixture being obviously regulated by the prevailing market prices.
In many instances the proportions of such mixtures are kept secret by the manufacturer as matters of importance, and every individual manufacturer has his own method and specialities as regards such blends.
We compare here a few verified blends:
1.2.Caracas}of each 1 partCaracas= 1 partGuayaquilBahia= 5 parts3.4.Maracaibo}each 1 partTrinidad}equal partsMaragnonMaragnon5.6.Caracas= 1 part1 part AribaMaragnon= 2 parts1 part Surinam1 part Trinidad7.8.1 part Ariba3 parts Ariba1 part Trinidad1 part Trinidad1 part Surinam1 part Surinam1 part Caracas1 part Caracas9.1 part Machala1 part St. Thomas
Ceylon cacaos are not used so much as mixing varieties, but almost exclusively as covering agents, to make other cacaos lighter coloured (sometimes almost approaching yellow).
The beans are weighed off in these proportions on a sensitive scale, and then passed on to be ground and triturated into cacao paste.
Formerly the roasted, crushed, and decorticated beans were frequently ground before being transferred to the “Melangeur”,—a machine that will be described later—, in which they were then reduced to a finer state of sub-division and lastly mixed with sugar. For this grinding, mills of various construction were employed (as Weldon, Pintus etc.). But as time rolled on the Melangeur took the place of these preliminary grinding mills, and in this it was endeavoured to effect that fine division of the cacao mass which is essential to the production of a homogeneous cacao and sugar intermixture, but without complete success. Cylinder rolling machines (French method) were the first to attain this result.
At the present time, the roasted and cleansed kernels are ground so fine as to become a semi-liquid when subjected to heat, and that is done whatever the ultimate destiny of the cacao, whether itbe intended for chocolate or cocoa powder. This object is obtained by means of special mills, constructed with “Over-runners
Fig. 23.
Fig. 23.
Fig. 24 a.
Fig. 24 a.
These cacao mills, which were formerly but seldom met with in chocolate factories, have now become indispensable necessaries, since they have the advantage:
1. of rendering the cacao mass in this semi-glucose form more easily miscible with sugar, a factor of the highest importance for the commoner and cheaper qualities of chocolate;
2. of grinding the cacao as fine as possible in one operation and the simplest manner.
Fig. 24 b.
Fig. 24 b.
Fig. 24 b.
Fig. 24 b.
Fig. 24 c.
Fig. 24 c.
But side by side with the appreciation which these mills met with, there arose a corresponding increase in the demands made on them, such as the utmost nicety, greatest possible output, and least possible necessity of after-heating, and these have been successively answered by twin, triple and at the present time even quadruple mills. fig. 23 shows a simple grinding mill which can only come intoconsideration in connection with the smallest of branches, whilst Fig. 24 a and b illustrates another with three successive stones arranged one above the other, such as will be found in all the larger factories of to-day. Also a triple mill but with grindstones of increasing size pictured in fig. 24 c. A mill possessing four pairs of grinding stones is given in fig. 25, and is calculated to meet each and every conceivable demand.
Whilst simple, double and triple mills are brought on the market in different sizes, corresponding to the outputs required, these quadruple mills are only constructed in the largest sizes. They grind perfectly, and without detriment to the flavour, deliver quantities of cacao figuring at from 1000 to 1200 kilos daily. There is naturally a larger output if the fatty contents of the cacao are considerable, a thorough roasting being always presupposed.
The axles occurring on these quadruple grinding mills are connected with one another by means of spur-wheels, and the axles themselves run in ball-bearings, which not only permits a perfectly noiseless operation of the machine, but also makes the action very easy, that is to say, dependent on only very little motor power. The cacao is raised to the hopper by means of an elevator, where the quantity introduced into the machine is regulated, and then passes between crushers occurring in the middle of the first pair of grinding stones, which it subsequently leaves as a pasty mass. It is then conducted along a groove into the second mill, and here undergoes further grinding, and so to the third and fourth, where the process can be described as trituration, for the cacao leaves the machine in liquid form. Only in this manner is it possible to obtain the finest ground product, without any disastrous accompaniment of excessive heating.
Cacao mills with one stone suffice for the production of chocolate mass on a small scale, but for the manufacture of cocoa powder, twin or triple grinders must be employed.
All these are of the “Over-runner” type, act by their own weight, and consequently do not involve the disastrous consequences which were entailed by the “Under-runners” tried formerly.
About the middle of the nineties of the last century, experiments were made with a view to superseding these types with mills having stones of varying sizes, and first larger upper stones of a grinding pair were tried, then larger under stones, but neither have been able to maintain themselves in the workshop, and the grinders of equal size still hold good as the fittest and most popular.