or by any other suitable means. The chocolate mass is fed into the
cylindrical hopper =a=, at the base of which occurs an archimedian
screw =b=, which is propelled by the shaft and cog-wheel system =c d
e= in the direction indicated by the arrow. Thus the chocolate mass is
forced into the box =f=, leaving which in cylindrical form, it succeeds
to the travelling band =h=. It is now almost entirely freed from air.
As the material is pushed forward on the band, it is cut off either by
a knife =g= fixed to the box =f=, or divided as far as possible into
equal parts by a double knife with adjustable blades corresponding
to the weight required for a chocolate square. This manipulation
presupposes a fair amount of skill on the part of the machinist, but
this once attained, the division ensues as precisely and simply as can
be desired.
Air-extracting machines of recent construction, although still
partially built on the above principle, are at the same time generally
developed as automatic dividing machines.
[Illustration: Fig. 49.]
[Illustration: Fig. 50.]
Fig. 50 shows such a machine for solid and semi-liquid chocolates. By
means of this, the material is next conducted along a vertical screw
path in even mass to the horizontal screw, and so a second filling with
the hand is rendered unnecessary. After it has been freed from air in
this, it enters a revolverlike cutter, which discharges the divided
portions on a travelling belt. On the latter it is conducted to a table
standing near, where it is laid into moulds. The machine is of very
strong make, and puts out from 15-250 gr, divided into approximately
10-25000 squares, within a space of ten hours.
[Illustration: Fig. 51 a.]
Figs. 51 a and b give finally two of the best known types which have
a very extensive application, protected by patent imperial (Germany),
and built by J. M. Lehmann, Herm. Baumeister, J. S. Petzholdt in
Döhlen, G, near Dresden and others. With this patent dividing machine
of J. M. Lehmann, solid and semi-liquid chocolate material, as also
nut and almond chocolates are divided exactly, in any weight from 18
to 250 grammes, and then conducted in strips of equal size to the
mould previously mentioned. As far as cleanliness, purity, and easy
management are concerned, it fulfills all the demands which can be
expected of the most modern machine.
[Illustration: Fig. 51 b.]
IV. Moulding of the Chocolate.
[Illustration: Fig. 52.]
11. ~Transference to the Moulds.~
The pieces of chocolate, on emerging from the dividing processes, are
placed separately in iron moulds, that is to say, as far as this has
not already been done in the dividing machine. It is important that
these should have the same temperature as the chocolate mass, in order
to prevent the formation of spots on the surface of the cakes, and to
obtain a good and non-greyish fracture. The temperature for moulding
smaller objects can be fixed at between 27° and 32° C. and for the
larger may be considerably lower. In summer also, moulding may be
proceeded with at a lower temperature than in winter. According to a
note in the Gordian (1895, No. 4) the moulding may be carried out in
summer, when the atmospheric temperature is;
from 25-31° C, at 26-27·5° C
" 18·5-25° C, at 28·5-30° C
" 12·5-18·5° C, at 31-32·5° C
In cold weather, the cakes may be moulded at a temperature of from
32·5-35° C., according to their thickness. When not manufactured in
the automatic machine shown in fig. 48, the mass should be otherwise
controlled as regards temperature, which should be registered by a
thermometer introduced therein. The moulds are for the most part
filled with plastic and liquid chocolates, and their depths determined
and modified by the weight of material which they are destined to
receive.
Fig. 52 shows a machine which conducts the semi-fluid mass to the
moulds in the following manner. The moulds are automatically introduced
under the apparatus, and filled from the small stirrer above. They then
succeed to the shaking table and are finally transported to the cooling
room. On this machine moulds of from 75-350 mm long and 75-225 mm broad
can safely be employed.
* * * * *
There are two different forms in which chocolate is sold, namely, that
intended for domestic purposes, and that which is to be consumed as an
article of luxury. The kinds known as cake, rock and roll chocolate
belong to the first class, the several pieces weighing 50, 100, 200,
250, 500 up to 5000 grammes. Tin-plate is the only material of which
moulds are made; and these generally have a capacity rather greater
than is necessary for holding the particular quantities to be moulded.
The chocolate is therefore, as described above, divided into given
weights, and generally deposited direct in the moulds by the dividing
machine. The divided portions of chocolate are pressed down in the
moulds by hand, equally distributed in the latter, and then transferred
in the moulds to the shaking table or combination of shaking tables
to be described later. On the shaking table the soft chocolate soon
penetrates completely into all the corners and impressions of the
stamped tin moulds. The removal of the cooled cakes from the moulds is
easily effected by pressing.
These moulds are generally provided with from four to ten ridges or
indentations, so that the chocolate can be conveniently divided, and as
required for use. Others again have a similar number of compartments.
The compartments may be impressed with any kind of inscription, so that
such information as the name of a firm can always be reproduced on the
cakes.
Broken chocolate is generally of inferior quality, brought on the
market without any protective covering.
In those kinds of chocolate which are known as articles of luxury a
distinction is to be made between;
1. Those moulds which are in one piece and completely filled with
chocolate, so that the superfluous mass can be removed by a knife. In
such cases the weight of the cakes is exactly regulated by the capacity
of the moulds.
2. Those intended for moulding various figures of fruit etc. in which
two or three parts make a closed space which is of the form desired.
Among the moulds of the first type must be numbered those used in the
preparation of small tablets and sticks, and the sweetmeats known as
Napolitains and Croquettes.
The second class comprises moulds for making chocolate cigars and
chocolate eggs, and also the double moulds.
The moulds for the smaller tablets, cream sticks, napolitains and
croquettes are also made exclusively from tin-plate, and the separate
parts are enclosed in a stout iron frame, the top of which is ground
down smooth, so that any superfluous portion of the filling can easily
be scraped away. In that way from six to thirty pieces can be cast in
one mould at the same time: the cooled chocolate can be released from
the moulds by gently tapping one corner against a table. In napolitain
moulds protecting hooks are attached, to avoid their sustaining any
injury in this operation.
Examples of the more frequent moulds.
1. ~Chocolate Cigars.~
These are made either by introducing the chocolate mass between the
two halves of a double mould, of which each corresponds to a half of
the cigar shape to be moulded and which each fit exactly one on the
other; or else by pouring it into hollow moulds stamped out of one
complete piece. Moulding presses[117] are utilised in the manufacture
of material ~en masse~. In these the cigars are filled into
iron moulds, afterwards held together by means of iron combs, and so
introduced in to the press. For each size and shape special moulds
and plates are essential. Neither barium sulphate nor zinc white may
be employed to produce an imitation of the ash on ordinary cigars, as
both are objected to by health inspectors; nor are they necessary, for
in phosphate of lime (tricalcium carbonate) we possess a perfectly
harmless and at the same time efficient substitute, when it is mixed up
with starch syrup.
Other figures, such as fish etc., may also be produced in chocolate, by
means of the moulding press, when it is furnished with stamped moulds,
corresponding to the forms required.
2. ~Chocolate eggs.~
These are generally made hollow, unless they are very small, by
pressing chocolate in two halves of an egg-shaped mould and then
uniting the two parts. Another method patented by Th. Berger of
Hamburg[118] seems less practical. A mould is made of soft sheet
caoutchouc blown out; this is dipped into liquid chocolate and, after
the adhering coating has hardened, the air is let out of the mould. The
use of caoutchouc moulds would render this method too costly, since the
alternation of temperature soon makes the caoutchouc unserviceable.
3. ~Various figures, fruits, animals, and other small objects.~
Double moulds are used for making these objects in chocolate,
consisting sometimes of three or four parts; they are made either of
sheet iron, tinned, or, for more complicated forms, the moulds are cast
in tin, but these latter are not so durable as those of tinned sheet
iron with strong iron frames.
The several parts of the moulds, after having soft chocolate mass
pressed into them, are put together and excess of material is removed
by requisite pressure by the use of a press of the kind made by A.
Reiche in Dresden, which will admit of a large number of moulds
being placed in it at a time. By the use of such a press the moulds
are protected from injury, and the objects moulded have a better
appearance, as a result of the uniform as well as strong pressure
exerted.
After cooling, the moulded objects are readily detached from the moulds
and they only require to be scraped clean, or further ornamented as may
be desired. That is done in various ways, for example by painting with
coloured cacao butter.
4. ~Crumb Chocolate.~
This term is applied to the small pieces of chocolate of truncated
conical shape, with from 4 to 5 smooth surfaces. They are made by
a machine specially constructed for the purpose by A. Reiche (No.
1550); it consists of a four-cornered box with a removable bottom.
Inside the box there is a false bottom, from 1 to 2 cm above the other
bottom, which is fitted with a removable sheet iron plate, in which
pentagonal holes are stamped. A knife can be introduced at one corner
of the bottom of the box. After sufficient chocolate has been made to
penetrate through the pentagonal holes by agitating the box on the
table, the knife is rapidly drawn across the bottom and the box raised
up. The sheet iron plate is then taken out, and by gently tapping one
corner the small pieces of chocolate are shaken out.
5. ~Small tablets, sticks, fruits or figures filled with cream.~
These are prepared by pouring the cream contents in either wooden or
iron moulds, previously dusted with a little flour, and then moulding
round them chocolate in whatever form is required, always taking care
that this is kept as soft and plastic as possible, a suitable addition
of cacao butter proving invaluable for the purpose.
In former times chocolate moulds were manufactured exclusively in
France, where the firm Létang of Paris enjoyed what was to all
intents and purposes a world monopoly. But since the year 1870 the
oft-mentioned firm of Reiche in Dresden-Plauen has taken up the
manufacture, and has succeeded in conquering the market in a remarkably
short time. The moulds of this firm satisfy each and every possible
requirement, although it would be no disadvantage if the old type of
pattern mould were cleared away at one and the same time with the old
routine, to make room for a little artistic skill and embellishment.
Recently Reiche has brought out a special machine intended as an easy
and practical cleanser of his many moulds, which include bonbon cutters
and cutting rollers, numbering stamps, chocolate slicers, roller
machine boxes etc. He has lately brought on to the market a special
machine for quickly and efficiently cleaning the moulds, which is
illustrated in fig. 53.
In one end, a circular brush is introduced, and against this the moulds
to be cleaned are firmly pressed. In consequence of the large number of
revolutions which this brush passes through, the moulds are cleansed
of still adhering masses of chocolate in a half or third of the time
occupied when hand labour is employed. At the other end of the shaft
occurs a duster, sprinkled with Vienna white (a lime), which polishes
off the moulds previously and thoroughly cleaned by the circular brush.
The great advantage of this machine is that the daily expenditure on
polishing is considerably reduced One girl can do the work of two hand
workers, when this machine is employed. In addition, it makes possible
a continual touching up of the material used in the making of the
moulds, a ventilating apparatus removing all traces of dust.
[Illustration: Fig. 53.]
12. ~The Shaking Table.~
The pasty chocolate mass fills itself into the chocolate moulds
spontaneously, in consequence of its soft consistency. Yet to share it
evenly throughout the mould, so that it adapts itself to every bend
and hollow there occurring, and further to bring to the surface any
possible bubbles of air evident in the mass, the chocolate is whilst
still in the moulds subjected to brisk shaking.
This is effected by placing the chocolate on trays and transferring
these to the shaking table, of which types and construction are at the
present time manifold and various, the best and oldest being given in
front elevation below (Fig. 54).
[Illustration: Fig. 54.]
The movable slab =a=, fitted with an upright rim at its edges, has
underneath two projecting pieces =d=, working against deeply toothed
wheels =e=, which fastened on the shaft =b=, are driven round by the
pulleys =c=. The teeth of the wheels catch on the projecting pieces at
every revolution of the shaft and push them rather gently on one side,
and when the tooth-points slide from under the slab, it drops down as
much as it has been previously raised. Each tooth of the wheel coming
into contact with the projections, the same motion is repeated several
times, causing the slab to oscillate up and down.
This oscillation of the slab is controlled by means of a hand lever
=f=, occurring on the shaft =g=, and fixed crosswise thereon, so that
we can only show it in cross section on the diagram. The lever =f=
attaches itself to the under part of the slab, raises it, and so throws
the wheels out of contact with the projecting pieces, but without
stopping the rotation of the shaft =b=.
Shaking tables have also witnessed considerable improvements with the
lapse of time, and we shall now proceed to treat these in more detail,
especially as several recent constructions offer and illustrate many
interesting mechanical points.
[Illustration: Fig. 55.]
[Illustration: Fig. 56.]
An old type of machine, that is nevertheless still much employed, is
illustrated in fig. 55. Here the slab is caused to osculate by shaking
wheels introduced underneath, each possessing six, eight, or more
teeth. The slab is raised and lowered by contact with wedge-shaped
parts, the effect produced being greater or less according as the
moulds are large or small, heavy or light, and in proportion to the
consistency of the chocolate mass which they contain, e. g. whether it
is solid or semi-liquid.
Quite an improved construction is shown in fig. 56. Here the table
is attached to a vertical axle, which is moved up and down by means
of a toothed wheel fixed on its bottom end. There is also a cylinder
arrangement under the whole machine to assist in controlling the
vertical motion of the shaft, and as it is provided with automatic
lubrication, there is no danger of any wearing out of the apparatus and
consequent irregularity of functioning.
The shaking and jerking of the slabs is in itself attended by a
considerable amount of noise, and when to this is added that caused by
the tables, it will be seen that a chocolate factory may become to its
neighbours a very serious source of objection. For years attempts have
therefore been made to construct shaking tables, so that they would
not cause any greater noise than is absolutely inevitable. Pneumatic
contrivances and caoutchouc have met with right royal success in this
connection.
[Illustration: Fig. 57.]
The most recent and probably the most perfectly constructed shaking
table is given in figs. 57 and 57 a. It embodies all the latest
improvements and is self lubricating, a fact of the highest importance
as releasing the strain on the attendance, which would need to be very
perfect to ensure absence of noise in the case of a machine making
800 strokes a minute. When it is considered that the moulding room
is generally managed by girls who neither possess knowledge of, nor
interest in, the machines, the advantages of such automatic lubrication
become even more apparent.
[Illustration: Fig. 57 a.]
[Illustration: Figs. 58 and 58 a.]
Apart from the automatic lubrication, in itself a sufficient guarantee
for the efficiency of the machine, screws and nuts are entirely avoided
on this machine. The motive mechanism is also interesting. By a special
arrangement, the number of revolutions in relation to the number of
the elevations of the slab is reduced to one fourth, viz., from 760 to
190. Since the elevation of the slab can be regulated to zero, a loose
pulley for shifting the driving belt is unnecessary; in addition, the
driving shaft makes only a small number of revolutions, and works in
oil. The round shaped upright serves to carry the vertically moving
frame =i=, which supports the slab moving in an oiled groove at =s=,
and which is supported underneath by the pivot =m=. Both at =m= and
=s= there is automatic lubrication. The bearings of the spindle
=n=, attached to the upright, work into left and right screw threads
at =oo=, to which points the ends of a broad leather belt =p= are
attached, passing over the roller =g=, by which the frame =i= is
suspended. The driving pulley =k=, running in oil, carries in its
centre the four rollers =l=, which turn round and round the pulley =k=,
so as to come into contact with the belt =p= and press it outwards on
both sides. At the same time it shortens the belt in the vertical axle,
so raising up the table slab =i=. This is repeated four times by one
revolution of the driving pulley, so that working with 190 revolutions
a minute, the slab is raised 760 times. According as the screws =oo=
are moved to or from the centre, the vertical movement of the slab can
be increased or decreased to a point when the slab is completely out
of action, i. e. when the rollers l no longer touch the belt =p=. Under
favourable local conditions, a number of such tables can be driven by
one shaft, so that only one pulley and a single driving belt would be
needed, though each table would work quite independently of the others.
Such an arrangement is shown in figures 58 and 58 a.
[Illustration: Fig. 58 b.]
This shaking table, though only recently introduced, has quickly made
itself popular, and is especially suitable for the preparation of
readily liquefiable chocolate. The gentle vibratory motion produced by
this shaking table and its exact adjustability admit of the thinnest
cakes being made in a perfectly uniform thickness, without any
objectionable projections round their edges. Besides the shaking tables
of this construction there are others made in such a way that whether
the moulds are light or heavy, small or large, the slab is always
raised to the same height, the working of the slab being adjusted by
altering the number of revolutions. The manipulation of these tables is
much more difficult than that of tables constructed as above described,
and that is probably the reason why these have for decades been scarce
on the market.
The moulded chocolate spread out on trays is transferred as rapidly as
possible to the cooling chamber, with which we shall conclude section
IV.
Instead of several shaking tables alternately receiving the moulds,
which involve frequent changes, so-called shaking systems (fig. 58b)
have been generally adopted of late. They consist of a number of
shaking tables, having their frames attached to each other, possessing
a common motor control, and having their slabs arranged one after the
other in such a way that the filled moulds slowly proceeding from the
dividing machine can be automatically conducted over them. The shaken
moulds are then passed on to further processes, or they enter the
cooling chambers at once. The advantage of the shaking table system
lies in a reduction of the number of hands, who only need to be in
attendance at each end of the system, and further in the regularity,
both as regards time and strength, which prevails in connection with
the shaking of each mould.
13. ~Cooling the chocolate.~
Experience has shown that the more rapidly the moulded chocolate is
cooled the finer is its texture and the more uniform the appearance of
the fractured surface. That is due to the formation of smaller crystals
of the fat when the cooling is rapid, while in slow cooling larger
crystals are formed and the fracture consequently becomes dull and
greyish.
Formerly it was possible to distinguish chocolate made in summer from
that made in winter by the more uniform appearance of the fracture,
that was, in the latter case, the result of more rapid cooling.
At present, however, manufacturers are no longer dependent upon
favorable atmospheric conditions in that respect, for by suitable
arrangements it is now possible to produce the reduced temperature
requisite by artificial means.
The most suitable cooling chamber is an underground space which should,
however, be so situated as to be in convenient communication with the
moulding room. The cheapest and simplest place for a cooling chamber
is a cellar, if it be properly constructed and dry, as well as large
enough to contain the quantity of chocolate made in one day’s working.
The best temperature to be kept up ranges from 8° to 10° C. Within
those limits there is no danger of the chocolate being coated with
moisture, or that it will acquire a coarse grained texture by lying too
long. The following rules will serve for guidance in regard to this
point:
Generally, chocolate presents the finest fracture when it has been
fully levigated and when it contains a considerable amount of fat,
provided that the fat present is only cacao butter. Those kinds which
are not so well levigated, or have had some addition of foreign fat
of higher melting point, show an inferior fracture. It is possible to
obtain an equally vitreous fracture in a less cold cellar (16° C. and
upwards) when the chocolate is moulded at a temperature corresponding
to that of the cellar; to effect that, the chocolate should be moulded
at a proportionally lower temperature the warmer the cellar is. The
difference can be seen by the appearance of pale red spots on the
surface. When it is desired to dispense with artificial cooling, the
cellar should be as much as possible below the surface of the ground;
it should also be of sufficient height, not less than 3 m. If the
situation and height of the cellar be properly adjusted, the requisite
area for disposing of a daily production amounting to 5000 kilos
would be 400 sq. m. The cellar must be well ventilated and furnished
with double windows, so placed as to open towards the north and east.
Discharges of warm waste water, as well as steam pipes or furnaces
should be kept as far distant from the cellar as possible. The internal
arrangement of the cellar should be of such a nature that the whole
of the chocolate to be cooled can be deposited upon the floor, since
that is the place where cooling takes place most rapidly. With that
object in view it is desirable to construct brickwork pillars about 25
cm high, covered with white tiles. Passages are arranged between these
pillars. The cellar should be entered by as few persons as possible
and, therefore, the cooled cakes of chocolate should be taken at once,
in the moulds, to an adjoining room to be turned out and passed on to
the packing room and store.
Most of the existing factories, that have been established for any
time (large and small) have had to adopt artificial means of cooling,
because in most instances the quantity of chocolate to be cooled daily
has, in course of time, increased tenfold. The machine rooms have been
enlarged, the number of machines has also been increased, while the
cooling cellar has remained in its formerly modest proportions. But
those circumstances are not the only reasons for having recourse to
artificial refrigeration, which is often necessary in consequence of
the inconvenient situation of the cellar and the high underground water
level.