Methods and systems for making aerated candy

A candy making system wherein a viscous candy mass is cooked and continuously fed through a closed chamber reactor wherein a gas, such as air under pressure, is homogeneously intermixed with the continuously proceeding melt product stream to incorporate gas bubbles of a predetermined microscopic size therein. The candy is cooked at a temperature well below its heat degradation temperature until a relatively high viscosity mass is obtained and the cooked viscosity is substantially maintained during the passage of the mass through the reactor chamber while elongated bubbles repeatedly created in the mass are repeatedly sliced when the product is forced through reduced size openings and a knife moves through the product at a speed such as to slice the elongated bubbles. The product is discharged from the chamber to atmosphere at the bubble slicing viscosity which may be described as "taffy-like".

The present invention is directed to a system for particularly making hard 
candy which incorporates gas bubbles for the purpose of decreasing its 
density and enhancing its appeal to the purchasing public. Typically 
today, and for a very long time, candy has been manufactured by subjecting 
it to a pulling and folding operation which entraps air in the product in 
a batch operation. 
Other systems for making candies, and particularly those comprising a candy 
and chewing gum mixture, have been suggested and reference is made, for 
instance, to Bowman Pat. No. 2,197,919, granted Apr. 23, 1940, wherein air 
is mechanically incorporated in candy at a time when the viscosity of the 
candy mixture is low. In this process, the liquid candy mixture is beaten 
by high velocity paddles to achieve a subdivision of air bubbles which are 
incorporated with the low viscosity candy mixture. Thereafter, the candy 
mixture, with or without the additional incorporation of a chewing gum 
base, is moved through a cooling and extruding apparatus wherein its 
viscosity is increased to a point such that it can maintain the suspended 
air bubbles at the time of discharge to atmospheric conditions. 
During the course of an investigation which was conducted, the following 
listed additional patents were drawn to applicant's attention: 
2,538,466 
3,000,618 
3,012,893 
3,066,707 
3,081,069 
3,164,107 
3,167,034 
3,170,608 
3,254,801 
3,349,438 
3,652,062 
3,985,909 
3,985,910 
4,001,457 
One of the prime objects of the present invention is to provide an improved 
continuous method which homogeneously incorporates gas in a viscous candy 
mass and permits the release of the candy mass to atmosphere after a 
repeated series of gas bubble elongations and slicings. The improved 
system does not require movement of the mass through a cooling extruder 
prior to release. 
Another object of the invention is to provide a system which manufactures a 
desired low density candy in an efficient and reliable manner and produces 
a stable product which does not require the addition of surface 
stabilizing agents to prevent coalescense and migration of the gas bubbles 
in the product. 
Another object of the invention is to provide a system which need not 
operate at temperatures close to the product decomposition temperature and 
which, because gas incorporation is accomplished at lower temperatures, 
avoids the heat degradation sometimes encountered with prior processes. 
Still a further object of the invention is to provide a system of the 
character described wherein a greater volume of air can be incorporated in 
high sugar content, hard candy mix by utilizing a back pressure to control 
the pressure in the gas incorporating chamber.

SUMMARY OF THE INVENTION 
An improved system for incorporating gas under pressure wherein a high 
viscosity candy mass is moved from the cooker through a pressurized closed 
container and gas bubbles, which are homogeneously blended in the candy 
mixture are elongated, and then sliced into sections when low velocity 
knives are moved through the product. The "work energy" input is removed 
from the candy mass as the mass moves through the chamber and the 
temperature of the product is controlled to substantially maintain the 
viscosity of the mass and prevent migration and coalescense of the 
subdivided bubbles. Finally, the mass, still at the bubble slicing 
viscosity, is discharged to atmosphere. 
Referring now more particularly in the first instance to FIG. 1, a batch 
candy mixer, generally designated 10, is shown as including a vat 11, a 
heating unit 12, and a rotary blade mixer 13, powered by a motor 14. While 
preferably a continuous type candy ingredient cooker will be used, for the 
purpose of convenience, a batch mixer is shown as leading to a jacketed 
holding tank which is continuously maintained partly full of the viscous 
candy mass which is manufactured in the unit 10 so that it can 
continuously supply the candy mass to a processing unit generally 
designated 16, wherein the gas, such as air under pressure, is 
incorporated into the candy mix. A hot water circulating unit 17 may be 
provided for maintaining the temperature of the candy mass at the desired 
level in storage tank 15, and a pump 18 can be provided for moving the 
candy mass from the storage tank 15 to an aerator 16, which we also choose 
to term a reactor, via the line 19. 
As noted, a hot water circulating unit 20 may also be provided for heating 
the discharge line 19 from tank 15 to maintain the mass sufficiently fluid 
for the pump 18 to operate efficiently. A suitable compressor 21 may be 
connected to the aerator 16 via line 22, and preferably has a gas flow 
meter 23 therein to meter measured amounts of air under pressure to the 
candy mass in a continuous manner. It is to be understood that reactor 16 
is cooled, in a manner which will be described, by a recirculating cooling 
water unit 24 as shown. 
In cooking unit 10, the candy mixture is heated to a cooking temperature - 
which typically may be of about 300.degree. F. When cooking has been 
accomplished and the desired viscosity achieved, the candy is released, 
and its viscosity is maintained in tank 15, from which it is continuously 
pumped to the aerator 16. When the candy mass reaches reactor 16, it is 
still at a relatively high viscosity, i.e. in the range 1000 - 100,000 
centipoises (cps). Its temperature has been allowed to cool only slightly 
from the cooking temperature and is significantly below a temperature at 
which heat degradation might occur. Basically, the viscosity utilized may 
be said to be the high viscosity which substantially is the viscosity at 
which the product is released from the cooker. The temperature at which it 
enters reactor 16, may typically be considered to be about 290.degree. F. 
which is close to the temperature of release from the cooker. The material 
may be considered to incorporate about five percent moisture or less after 
cooking. With the present process, cooking can proceed at a lower 
temperature because a more viscous "out" product is desired, and heat 
degradation effects are accordingly minimized. 
Referring now more particularly to FIG. 2, wherein the reactor 16 is shown 
in more detail, a central shaft 25 is provided, supported by bearings 26 
at either end. It is driven by a motor M at a relatively low speed, in the 
range of 50 to 100 rpm. Such speeds at 100 rpm produce peripheral 
velocities in the neighborhood of 250 feet per minute as distinguished 
from speeds in the range of 3000 feet per minute in the Bowman process. 
Shaft 25 extends through openings 27a, provided in a series of stationary 
heat transfer plates 27, provided with coolant circulating passages 28 
which are supplied with circulated cooling fluid from the cooling watering 
unit 24. It will be noted that the plates 27, which do not rotate with 
shaft 25, are recessed as at 29 to provide rotor chambers 30 in which 
rotor severing knives 36, keyed to the shaft 25, are provided. A frame 
generally designated F is provided for supporting the bearings 26 via 
blocks 31 and beams 32, supported on a bed 33. A beam 34 fixed on beams 32 
supports the stationary heat transfer plates 27 via blocks 35. It will be 
noted that each of the transfer plates 27 also includes material 
subdividing ports 37, arranged in a pattern such as shown in FIG. 3. 
Provided in the left endmost plate 27, is an entry port 39 for the entry 
of the viscous candy material via line 19. The outlet port is at the 
opposite right end of the reactor 16 at 40, and a discharge passage 41 
leads from the end of the endmost downstream chamber to the outlet 40 at 
the opposite end of the machine as shown. At the left end of the unit 16, 
a seal member generally designated S, is provided and air line a is shown 
as admitting air under pressure through the passage y to a sealed chamber 
z. 
In practice, the candy mix is continuously pumped to the inlet 39. Air 
under pressure, i.e. up to about 300 p.s.i., which is to be incorporated 
in the candy mass in the form of air bubbles, is admitted through the air 
line a, the passage y, and the chamber z, past the inner periphery of the 
seal S to the first rotor chamber 30'. By admitting the air under pressure 
to the seal S, a dual function is achieved. Not only is the air readily 
supplied to the first chamber 30, but because of its pressure, it prevents 
material from entering the seal S, and hardening to interfere with the 
operation of the machine. 
The rotors 36 may be constructed in the manner indicated in FIG. 3, with a 
plurality of arms 36a having what may be termed cutting edges 36b. These 
arms 36a continuously wipe the candy mass over the heat exchange surfaces 
of the stationary heat exchange plates 27. They also slice the air bubbles 
which are formed in the highly viscous molten mass with the introduction 
of air under pressure to the leading chamber 30', and thus comminute the 
air bubbles to provide an increased number of air bubbles of smaller size 
in the candy mass. 
A further function of the rotors 36 is to remix the material that has been 
wiped on the heat transfer surfaces of plates 27 with the main mass of 
material to obtain an average temperature of the mass which is best suited 
to air bubble elongation and subdivision. The material proceeds linearly 
through the openings 37 in an axial direction from left to right, from 
rotor chamber 30 to rotor chamber 30. The effect of drawing subdivided 
portions of a material at this viscosity through openings 37 is to stretch 
or elongate the material and the air bubbles incorporated therein. 
However, it should be understood that the process also involves 
continuously wiping a part of the candy mass against consecutive heat 
removing surfaces after each severing procedure and remixing it to achieve 
an average temperature in the mass suited to air pocket slicing. 
Finally, when the candy mass is discharged out discharge pipe 40 to 
atmosphere, the bubbles are micron size and what remains is essentially a 
stable, low density viscous candy mass. Essentially, in the unit 16, the 
work energy imparted and, in some cases, also the heat of crystallization, 
is removed so that the air bubbles remain small and do not migrate out of 
the candy mass. Also typically cooling will be controlled so there is a 
gradual temperature loss in the material as it proceeds through the 
machine, and so its viscosity remains high at substantially its viscosity 
of release from the cooker, or higher, and its viscosity throughout its 
passage through the unit 16 may be termed the "bubble slicing" viscosity. 
It will be noted that at the discharge end of the machine, the end plate 42 
has an enlarged opening 43. The candy mass then must proceed out a 
tapering flow restricting passage 44 provided between an inner metering 
sleeve 45 and an outer metering sleeve 46. The outer sleeve 46 is mounted 
for axial adjustment on a threaded portion 47 of shaft 25 and is 
exteriorly threaded as at 48 to accommodate a handle ring 49 thereon, 
having opening 50 for an adjusting handle 51 which can also detachably 
enter an opening 52 provided in the sleeve 46. An opening 53, provided in 
the sleeve 46 communicates with an opening 54 in a cage member 55 for 
supporting outer sleeve 46, which can be bolted to the end plate 42 as at 
56. A set screw device 58 permits the position of sleeve 46 to be held 
after its adjustment to desired position to impose the desired back 
pressure on the candy mass. The sleeve 45, of course, rotates with the 
shaft 25, whereas the sleeve 46 is supported stationarily via cage 55 by 
the end plate 42. The material proceeds out opening 43 and via passage 44 
to a chamber 57 leading to the ports 53, 54 and discharge pipe 40. To 
enlarge or reduce the size of annular passage 44, the position of sleeve 
46 can be adjusted axially relative to sleeve 45 by manipulating handle 
51, after manipulating the set screw device 58. 
The purpose of providing the restricted annular passage 44 is to create a 
back-pressure which acts in opposition to the pressure pumping the mixture 
through the machine and also the air pressure. Thus, while proceeding 
through the reactor unit 16, the viscous candy mass can be uniformly 
pressurized and a control of pressurization is provided which assures that 
the mass does not move through the machine too quickly to incorporate the 
desired amount of air. Typically, an increased pressure permits a greater 
quantity of smaller air bubbles to be incorporated in the candy mass and 
makes it possible to release a candy mass which may be fifty percent air 
and fifty percent candy. By keeping the candy in the reactor under a 
constant controlled pressure, substantially fine bubbles can be created 
such that when the candy is released to atmosphere and expands, a 
coalescense of bubbles does not occur. The pressure utilized in the 
chamber is no greater than the pump pressure moving the mass in to keep 
the reactor 16 filled and the air is metered in at this pressure. 
To contrast what is occurring in the present system with the prior art 
systems, attention is directed now to FIG. 4 wherein the long, well-known 
stretch and fold system to entrap air in candy is schematically 
illustrated. Each time the candy is folded, air is, of course, captured 
but the problem is that this operation is a batch operation rather than a 
continuous one. Processes of this type, accomplished either manually or 
with a folding machine, have been used for many years. 
FIG. 5 illustrates the effect obtained using the method described in the 
prior art Bowman U.S. Pat. No. 2,197,919, earlier mentioned, which 
utilizes an air bubble smashing principle. Here the paddles are driven at 
a high rate of speed in the neighborhood of 2,000 rpm and clearly impart 
considerable work energy heat to the product. The product proceeding past 
the impacting paddles is of low viscosity and so the bubbles would not 
elongate when passed through the restrictive air ports. A higher viscosity 
is required in a candy mass in which incorporated air can produce 
elongated bubbles and this method is to be distinguished from the bubble 
smashing principle employed in the prior art Bowman patent. 
FIG. 6 is a schematic view illustrating what happens in the system of the 
present invention, and essentially is an exploded view illustrating the 
elongation of the bubbles at a and the action of the rotor knife edges in 
slicing them into a far greater number of components at b. With 
applicant's method, a minimum work energy heat input is involved with 
rotation of the low viscosity rotor slicers 36 through the viscous candy 
mass. Because the candy is maintained in a condition of relatively higher 
viscosity, the material released is far more stable in that the bubbles do 
not tend to coalesce or migrate, even though upon release to atmosphere 
they tend to grow in size up to two and one-half fold. Essentially the 
pressure to which the material is subjected as it moves through the unit 
16 is a function of the control discharge passage 44, because the flow 
pressures generated by the pump, and supplied by the air under pressure, 
adjust to the internal pressure caused by the restricted valve passage 44. 
The present controlled process permits the bubbles to grow to the desired 
degree upon release to the pressure of the atmosphere. 
It is to be understood that the drawings and descriptive matter are in all 
cases to be interpreted as merely illustrative of the principles of the 
invention, rather than as limiting the same in any way, since it is 
contemplated that various changes may be made in various elements to 
achieve like results without departing from the spirit of the invention or 
the scope of the appended claims.