The present disclosure relates to the field of cheese making. In particular, the present disclosure relates to fusing curd.
This section is intended to introduce various aspects of the art, which may be associated with the present disclosure. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.
Cheese curds can constitute a final product for the purpose of eating as a snack or as an ingredient in preparing dishes such as poutine or can be considered as an intermediary product to be used in a subsequent cheese making process. The manufacturing of cheese curds requires that curd be fused, which involves intense manual labor and long time periods.
For example, when making cheddar cheese, curd is fused by being manually formed into a thick layer that is cut into slabs of curd and the slabs are stacked atop each other to form curd stacks. The cutting and manipulation of the curd and the stacking of curd slabs promotes the syneresis process necessary to produce cheese. The stacking of the slabs of curd results in pressure being applied to the slabs, which causes whey to be expelled from the slabs. After ten minutes or so, the slabs are turned over and are again stacked atop each other and, in some instances, individual stacks are stacked atop one another. This can be repeated a number of times until the acidity of the curd stacks reaches a target pH value (e.g., a value comprised between 5.1 and 5.3) and proteins become aligned in the stack. When the target pH is reached, the curd stacks are milled into pieces of curd (cheese curds), which can then be either salted and packaged for consumer distribution or used in a subsequent cheese making process. For example, when the cheese curds are used in making cheddar cheese or other types of salted or unsalted cheeses, the cheese curds are provided to a pressing device where they are pressed against each other to form a continuum and are subsequently cut into blocks of cheese, packaged and aged.
The curd stacks prepared using the manual curd fusing process outlined above still contain air pockets, water pockets and interstices such that when the curd stacks are subsequently subjected to the milling process, the resulting cheese curds are unevenly sized and include multiple fines, which give the cheese curds a poor appearance. Further, because the cheese curds are unevenly sized, it can become challenging to automatically package the cheese curds into packages that have a precise target weight.
Therefore, improvements in the manufacturing of cheese curds are desirable.
The present disclosure allows for the fusion of curd and the making of cheese curds without requiring vast amounts of manual labor. The curd can be fused in an apparatus configured to form a curd stack in a container that has a temperature comprised within a temperature range that favors acidification of the cheese curd in the curd stack. The formation of the curd stack compresses the cheese curd in the curd stack, which causes the curd stack to express whey as the acidification of the curd takes place and as the syneresis process takes place. The curd stack is subjected to a vacuum, which assists in the removal of air from the curd stack.
In an aspect, the present disclosure provides a method for producing cheese curds to be eaten as a snack, to be used in preparing a dish, or to be pressed together to form a block of cheese. The method comprises: obtaining the curd; stacking the cheese curd to obtain a curd stack; and subjecting the curd stack to a vacuum that has a sub-atmospheric pressure. Also, when the curd stack is subjected to the vacuum, maintaining the curd stack at a temperature comprised within a pre-determined temperature range, the temperature range being a range that supports micro-organism activity in the curd stack, which micro-organism activity acidifies the curd in the curd stack. The method further comprises removing whey expressed from the curd stack; and monitoring an acidity of the curd stack. When the acidity of the curd stack is within the pre-determined acidity range, cutting a block of curd from the curd stack, removing the block of curd from the vacuum, and cutting the block of curd into the cheese curds.
In some embodiments, maintaining the curd stack at the temperature comprised within a pre-determined temperature range includes heating the curd stack.
In some embodiments, monitoring the acidity of the curd stack includes monitoring the acidity of a bottom portion of the curd stack.
In some embodiments, monitoring the acidity of the curd stack includes monitoring a pH of the curd stack.
In some embodiments, cutting the block of curd from the curd stack is effected when a pH value of the curd stack is in a range of about 5.3 to about 5.1.
In some embodiments, maintaining the curd stack at the temperature comprised within the pre-determined temperature range includes maintaining the curd stack at a temperature comprised between about 28° C. and about 44° C.
In some embodiments, subjecting the curd stack to the vacuum at the sub-atmospheric pressure includes subjecting the curd stack to a vacuum having a pressure comprised between about 10 inches of mercury (about 339 mbar) and about 18 inches (about 610 mbar).
In some embodiments, removing the whey includes using a vacuum system to remove the whey.
In some embodiments, the method further comprises, prior to removing the block of curd from the vacuum, stretching the block of curd along an axis parallel to the curd stack, and laterally compressing the block of curd in a plane perpendicular to the curd stack.
In some embodiments, obtaining the curd includes obtaining curd having a pH within a range of about 6.3 to about 6.0.
In some embodiments, the method further comprises forming the curd in a cheese making vat prior to obtaining the curd.
In some embodiments, stacking the curd includes stacking the curd to a height selected to produce, at the bottom of the curd stack, a pressure comprised between about 0.02 kg/cm2 and about 0.05 kg/cm2.
The above aspects of the present disclosure allow for the production of a cheese block that has a continuous casein matrix, which is considerably free from water pockets, air pockets and interstices. Once obtained, the cheese block can be milled into cheese curds, which, because of the continuous casein matrix, have substantially similar dimensions and very few fines.
For simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the embodiments herein. Also, the description is not to be considered as limiting the scope of the embodiments described herein.
The present disclosure relates to an apparatus for fusing curd and to a method of fusing curd. The method of fusing curd and the apparatus for fusing curd of the present disclosure can provide fused curd which, when milled or cut into cheese curds, provides substantially evenly sized cheese curds with a reduced number of fines and can eliminate the manual labor required to fuse curd when compared to traditional, manual fusing of curd such as, for example, as part of a cheddaring process. The method of fusing curd and the apparatus for fusing curd in accordance with the present disclosure improves predictability of the quality of the cheese curds and allows flexibility in the curd fusing process.
Subsequent the production of the curd in the cheese-making vat 1, the curd is moved out of the cheese-making vat 1 and onto a perforated conveyor belt 2 (draining belt). The perforated conveyor belt 2 can comprise, for example, a mesh filter made of cloth, stainless steel or polypropylene. As the perforated conveyor belt 2 displaces the curd away from the cheese-making vat 1, whey contained in the curd is drained by gravity, through the perforated conveyor belt 2. The whey can be recovered and used in other processes. It is not necessary that a perforated conveyor belt be used to drain whey out of the curd. Rather, any suitable apparatus configured to drain whey from curd can be used without departing from the scope of the present disclosure. For example, a whey drainage drum or a whey screen and a non-perforated belt could be used instead of the perforated conveyor belt 2. The perforated conveyor belt 2 and the speed at which it conveys the curd can be configured to drain the curd of a pre-determined amount of whey as the curd is conveyed to an auger 3. For example, the perforated conveyor belt can be configured to drain the curd of 90% of its whey. Optionally, a mixing device can be located and configured to mix or toss the curd that is on the perforated conveyor belt 2 as the curd is being conveyed away from the cheese-making vat 1. The mixing/tossing can be implemented to further control the humidity level and the amount of whey in the curd.
The perforated conveyor belt 2 drains the curd from whey and moves the curd from the cheese-making vat 1 to the auger 3. As the curd is fed, by the perforated conveyor belt 2 to the auger 3, the auger 3 breaks up the curd and provides the (broken up) curd to a rotary valve 4. It is not necessary that an auger be used. Any suitable apparatus configured to break up curd can be used instead of an auger. In some cases, the skilled worker may recognize that the curd does not need to be broken up and, instead of the perforated conveyor belt 2 providing the curd to the auger 3, the perforated conveyor belt 2 can provide the curd directly to the rotary valve 4.
The rotary valve 4 has an air input portion connected to a blower 26 that is configured to push curd arriving in the rotary valve toward a cyclone separator 6 that separates the curd from air. The air blown by the blower 26 is provided and heated, by a heating apparatus 5, to a temperature selected to maintain the temperature of the curd at a target temperature, which can be selected as a function of a target rate of acidification of the cheese curd (change in the pH of the cheese curd as a function of time). Any suitable type of heating apparatus and blower can be used without departing from the scope of the present disclosure.
The rotary valve 4 dispenses the curd to the cyclone separator 6. It is not necessary that a rotary valve 4 be used to dispense the curd to the cyclone separator 6. Rather, any apparatus configured to dispense the curd to the cyclone separator can be used without departing from the scope of the present disclosure.
The curd and air arriving at the cyclone separator 6 are separated with the air exiting the cyclone separator 6 and the curd falling toward an airlock 50 formed in a conduit 52, between two butterfly valves 7 and 8. The airlock 50 allows to introduce curd into a container 54 that is under vacuum without breaking the vacuum in the container 54. The butterfly valves 7 and 8 are shown as being double butterfly valves; however, this need not be the case. The butterfly valves can be single butterfly valves without departing from the scope of the present disclosure. The vertical space between the butterfly valves 7 and 8 can be connected to a vacuum system 80 containing a vacuum pump (which could be the vacuum pump 25). The vacuum system 80 is equipped with a valve system that allows the aforementioned vertical space to be open to the atmosphere or, to alma the vertical space to be pumped down the same pressure as in the container 54. As such, the top butterfly valve 7 can be open when the vertical space is at atmosphere (i.e., at about the same pressure as in the cyclone separator) and the bottom butterfly valve 8 is closed. Further, the bottom butterfly valve 8 can be opened when the top butterfly valve 7 is closed and the vertical space between the two butterfly valves is at the same pressure as in the container 54. This allows each butterfly valve to be open only when both sides of the butterfly valve are at the same pressure. This reduces the wear and tear of the butterfly valves 7 and 9. In other embodiments, other types of valves can be used instead of, or in combination with butterfly valves without departing from the scope of the present disclosure. As an example, guillotine valves can be used.
The container 54 has a top portion 56 and a bottom portion 58. The top portion is connected to the conduit 52. The curd is received from the air lock 50 at the top portion 56. The curd falls onto a dispersing device 9, for example, a dispersion plate or dispersion cone. This allows the curd to disperse in the container 54 as it falls to the bottom portion 58 and accumulates in height to form a curd stack. As will be understood by the skilled worker, the presence of a dispersion device is not mandatory and other embodiments can function without the presence of a dispersion device.
The bottom portion 58 has a heat shroud 16 that surrounds the curd stack. This allows the curd stack to be maintained at a target temperature. The heat shroud 16 in the embodiment shown at
As will be understood by the skilled worker, the acidity of the whey changes as the mixture of whey and curd is transported from the cheese making vat 1 to the container 54. The whey acts as a solvent for the minerals present in the curd or curd structure: the more acidic the whey is, the more demineralization of the curd is important. As will be understood by the skilled worker, in order to avoid demineralization of the curd to occur too fast, it can be important to ensure that the pH of the whey prior to the curd entering the container 54 is at a value greater than, for example, about 5.8. This can be achieved by controlling, through known means, the time span during which the curd and whey mixture is conveyed from the cheese making vat 1 to the container 54 and by controlling the temperature of the whey and curd mixture as it is conveyed to the container 54.
In some embodiments, the surface occupied by the mesh window 500 or by the multiple mesh windows can be about 5% of the surface of the sieve container 53. Any other percentage value of the surface occupied by the mesh window 500 or by the multiple mesh windows that allows adequate draining of w-hey is to be considered within the scope of the present disclosure. As will be understood by the skilled worker the materials used in the apparatus embodiments of the present disclosure are preferably food grade material and can include, for the sieve container, food grade aluminum, food grade stainless steel or any other suitable material.
In the embodiment of
The top portion 56 is connected to the vacuum pump 25 through a connector 12. In this embodiment, a container 13 is in line between the connector 12 and the vacuum pump 25. The container 13 is configured to receive and contain any whey that reaches the connector 12.
The pressure to which the curd in the curd stack is subjected to increases as curd is fed in the container 54. The pressure at the bottom of the curd stack is greater at the bottom of the stack than higher in the stack. This pressure allows the curd, no\v mostly free of whey, to fuse into a continuous stack, i.e. a stack free of interstices (air pockets) and pockets of water or, at least having less interstices and pockets of water than a curd stack produce by the customary manual process. Additionally, the inventor has discovered that the application of a vacuum to the container 54 produces a superior continuous stack of curd in comparison to a stack of curd produced without the application of a vacuum to the container. It is believed that forming a curd stack under vacuum further helps in decreasing the amount of air trapped in the curd stack. That is, forming the curd stack under vacuum helps decrease the number of air pockets and interstices in the curd stack. The pressure at the bottom of the curd stack or at a bottom portion of the curd stack can be comprised between about 0.02 kg/cm2 and about 0.05 kg/cm2. For example, the pressure can be about 0.045 kg/cm2, which is produced by a curd stack having a height of about 5 meters. However, any other suitable pressure at the bottom of the curd stack can be used without departing from the scope of the present disclosure.
The bottom portion 58 of the container 54 has a funnel shaped portion [19, 66] that funnels the curd stack into a conduit 68. The funneling of the curd stack causes lateral compression of the curd stack as well as longitudinal stretching of the curd stack. The lateral compression (compression in a plane that is perpendicular to the length of the curd stack or perpendicular to the length of the cylinder 54) and longitudinal stretching (stretching along the axis defined by length of the curd stack or the cylinder 54) helps create a fibrous texture in the curd stack, which contributes to the continuousness of the curd stack. As will be understood by the skilled worker, in some embodiments, the container 54 can be shaped as a circular cross-section cylinder and the funnel shaped portion [19, 66] can have a rectangular cross-section. Any other suitably shaped cylinder and funnel portion are to be considered within the scope of the present disclosure. The funnel shaped portion [19, 66] can be referred to as an output component of the apparatus for fusing curd.
The conduit 68 is equipped with two guillotine blades 20. Namely the top guillotine blade 70 and the bottom guillotine blade 72. The guillotine blades are configured to be open and closed sequentially in order to maintain vacuum in the container 56. With the bottom guillotine blade 72 closed, the top guillotine blade 70 is open, which allows the curd stack to move downward toward the second guillotine blade 72. When the curd stack rests on the guillotine blade 72, the first guillotine blade 70 is closed, thereby cutting a block portion of the curd stack, the block portion being located between the top guillotine blade 70 and the bottom guillotine blade 72. At this point, \Vith the top guillotine blade closed, the bottom guillotine blade 72 is open, which causes the block portion to fall onto a conveyor device 74. The conveyor device 74 conveys the block portion to a cutting device 22 that receives the block portion and cuts it or mills it into pieces of cheese, which constitute the cheese curds. The cutting device 22 can include a grid against which the block is pushed to product the pieces. Any other suitable device that can cut the portion of the curd stack into cheese curds is to be considered within the scope of the present disclosure. The guillotine blades 70 and 72 can be said to define an output device.
The pieces cheese (cheese curds) are then provided to a conveying device 23, which allows the pieces to cool as the conveying device 23 conveys the pieces toward a salting zone 24 where the pieces are salted. The time duration during which the curds are conveyed to the salting zone 24, which is the time during which the cheese curds cool, can be approximately 10 minutes. Any other suitable time duration can be used without departing from the scope of this disclosure. The salted cheese pieces can subsequently be bagged or be provided as an intermediary product for another cheese making operation.
Advantageously, the automated/mechanized method of fusing curd described above results is block of curds that have a continuous casein matrix substantially free of interstices and water pockets. The quality of the blocks of curd produced in accordance with the present disclosure is such that the cutting device does not encounter interstices or water pockets as the block is cut into pieces. This produces uniformly sized cheese curds without any substantial amount of curd fines. The uniform size of the pieces of curd simplifies the packaging of the pieces in that it is simpler to achieve the target weight of the curd package. Furthermore, the cheese curds obtained in accordance with the present disclosure have been found to have a particularly pleasant cheese squeak and mouth feel in comparison with cheese curds prepared by prior art methods.
The vacuum system 212 is coupled to the container 204 and is configured to produce a vacuum inside the container 204. The vacuum system 212 also allows to drain whey as it is expressed from a curd stack when the curd stack is being formed in the container 208. In this embodiment, the coupling of the vacuum system 212 to the container 204 is effected through vacuum ports 214 that fluidly connect the inside of the container 204 to conduits 216, which are connected to the vacuum system 212. The vacuum ports 214 in the present embodiment are spaced apart vertically, which provides redundancy in the event where one of the vacuum ports becomes obstructed. In the embodiment of
In the present embodiment, the rotary valve 210 allows the cheese curd arriving at the opening 202 to be transported through the conduit 200 and into the container while acting as an airlock. As such, the apparatus shown in
Rather than having a conductivity probe 18 as in the apparatus of
The container 204 can have any suitable shape and dimensions. For example, the container 205 can be cylinder-shaped with a diameter of 1.5 m and a height of between 2 m and 5 m or more. Any other suitable dimensions that allow to fuse curd such that a block from a curd stack is substantially free of air pockets, whey pockets and interstices are considered to be within the scope of the present disclosure. As will be understood by the skilled worker, the container 204 can have a transition region where the shape of the container goes from a circular cross-section cylinder to a rectangular or square cross section conduit (not shown).
As will be understood by the skilled worker, the vacuum system 212 of the embodiment of
At action 106, the curd stack is maintained at a pre-determined temperature, which can be selected to control the rate at which the curd acidifies; that temperature can depend on the type of cheese being made, etc. or, within a pre-determined range of syneresis temperatures. In some embodiments, the syneresis temperature can be between 28 and 44° C. For example, the temperature can be maintained by the heat shroud of
At action 108, whey expressed by the curd stack is removed, for example, by a vacuum system or vacuum pump. At action 110, the acidity of the curd stack is monitored, for example, by a pH meter. At action 112, when the acidity meets a pre-determined criteria, a block is cut off from the curd stack. Subsequently, the cut-off block can be milled to obtain cheese curds.
The properties of the curd produced by the curd producing apparatus (for example the cheese making vat 1 at
As will be understood by the skilled worker, the embodiments described in the present disclosure and their controllers can include a processor and a processor-readable memory that has recorded thereon instructions to be carried by the processor to perform method steps described herein. Further, embodiments of the disclosure can be represented as a computer program product stored in a machine-readable medium (also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer-readable program code embodied therein). The machine-readable medium can be any suitable tangible, non-transitory medium, including magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), memory device (volatile or non-volatile), or similar storage mechanism. The machine-readable medium can contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment of the disclosure. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described implementations can also be stored on the machine-readable medium. The instructions stored on the machine-readable medium can be executed by a processor or other suitable processing device and can interface with circuitry to perform the described tasks.
The above-described embodiments are intended to be examples only. Alterations, modifications and variations can be effected to the particular embodiments by those of skill in the art. The scope of the claims should not be limited by the particular embodiments set forth herein but should be construed in a manner consistent with the specification as a whole.
The present application is a Continuation of U.S. Ser. No. 17/277,072, which is a National Stage Entry of PCT/CA2019/051332, filed on 19 Sep. 2019. U.S. Ser. No. 17/277,072 entered the national stage on 17 Mar. 2021. PCT/CA2019/051332 claims priority to U.S. Provisional 62/733,253, filed on 19 Sep. 2018. Each of U.S. Ser. No. 17/277,072, PCT/CA2019/051332, and U.S. Provisional 62/733,253 is entitled APPARATUS AND METHOD FOR FUSING CURD. The content of each of U.S. Ser. No. 17/277,072, PCT/CA2019/051332, and U.S. Provisional 62/733,253 is incorporated herein by reference, in its entirety.
Number | Date | Country | |
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62733253 | Sep 2018 | US |
Number | Date | Country | |
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Parent | 17277072 | Mar 2021 | US |
Child | 18630673 | US |