Method for producing blocks of cheese

The invention relates to a method for producing cheese blocks from curd, wherein the cheese mass is placed in at least one cheese mold equipped with a pusher and in at least one cheese mold it is subjected to a vacuum treatment and pressing procedure, which pressing procedure is carried out during when at least one cheese mold is in the container in which the vacuum dominates.

[0002] In cheese production methods, the pressing procedure is mainly used to remove whey and air from the cheese mass. The cheese mass may, for example, consist of fresh or already pre-acidified non-coherent granular curd particles or curd particle assemblies, for example in the form of small lumps, strips or other shapes or, for example, a pre-shaped curd block. By pressing, a stabilized block is obtained, such that the curd particles adhere to each other. In this way, a coherent cheese mass is obtained, a block of cheese, and a crust forms on the outside of the block.

[0003] During the pressing operation, the cheese mass is held in a cheese mold having one or more movable sides. Usually it is a cover, but designs with a movable bottom or side wall are also possible. In the following, the starting point is for simplicity the most common design, the cheese mold having a movable cover. An external mechanical force is operated on a movable cover by a pneumatic cylinder or similar.

[0004] The pressing procedure is usually carried out in a number of successive pressing steps, with the excess whey and air trapped in the cheese mass and the cheese mass first being removed, the optional block form defined by the cheese mold and its cover is removed. The curd particles are thus pressed against each other, forming a coherent mass; and finally, by squeezing the cheese mass, a crust forms on the surface of the curd block.

[0005] This pressing procedure takes a long time and requires a lot of energy. In the past, many attempts have been made to accelerate pressing with the help of vacuum treatment and / or reduce the energy needed for it, while maintaining good quality of any cheese blocks.

[0006] For example, US-A-5082681 describes a method of producing cheddar cheese blocks in which the curd blocks obtained from the block molding machine are subjected to high vacuum and then briefly mechanically pressed, while the gas pressure increases to atmospheric pressure to achieve a skin on the block in a short time.

[0007] In addition, patent EP-B-1108362 discloses a method for producing blocks of semi-hard cheese from fresh granular curds, in which, in order to obtain an improved internal structure of the blocks, before the end of the pressure pressing procedure

-2atmospheric, a short pre-treatment procedure is used with a high vacuum of 95% or more.

[0008] EP 0 742 998 A1 discloses a method of producing cheese blocks of the type described above, wherein the curd is pressed under vacuum during a series of two or more cycles. In each pressing cycle, during the first phase of 20 to 25 minutes, pressing force is applied to the curd placed in the cheese mold, while the cheese mold is in the vacuum space. As a result, in the second phase of the respective compression cycle, the compression pressure is removed and a pressure that is equal to or greater than atmospheric pressure is created in the vacuum space. The second phase has a duration that is in the order of 30 seconds to two minutes. The compression pressure can be a mechanically applied compression pressure, but it can also be generated by the difference between ambient pressure and vacuum in the vacuum space.

[0009] Patent CA 1 040 571 A1 discloses a device for processing curd and similar materials and comprises a vacuum chamber; input material and a channel leading from the input means to the vacuum chamber are provided for the material. The channel is formed to compress material passing through it, and the means are provided to move the material from the input means, along the channel and into the vacuum chamber. Output means are provided in the vacuum chamber and the means are also equipped so that the material coming out of the vacuum chamber can move away from it.

The invention provides for an improved method by which cheese blocks having a good internal and external structure can be produced faster and / or with less energy consumption than with known techniques.

[0011] According to the invention, a method of the type described above is characterized in that the vacuum treatment comprises at least a first and a second stage, wherein in the first stage with the aid of a vacuum pump means a first vacuum is created in the container to remove the air and whey trapped from the cheese mass, and in the second stage the vacuum in the container is further reduced to the second vacuum, which has a value, at which the whey present in the cheese mass begins to boil and residual air and free whey are forced out of the cheese mass .

[0012] It is worth noting that while in the description and claims there is a reference to a cheese mold, it is understood to include a so-called multi-cheese mold, into which several cheese masses can be pressed simultaneously with several push rods.

[0013] Hereinafter, the invention will be further explained with reference to the accompanying drawings.

Fig. 1 schematically shows a vertical cross section of an example of a device for producing cheese blocks not according to the invention;

Fig. 2 schematically illustrates an explosive perspective view of a device similar to Fig. 1; and

Fig. 3 shows an outline of an example of the embodiment of the device of Fig. 1.

-3Fig. 1 schematically shows a vertical cross-section of an example of an apparatus 1 for producing cheese blocks not according to the invention. It should be noted that reference is made to blocks of cheese in this description and claims. They do not have to be rectangular blocks. The term "blocks" is understood to refer to all possible shapes of cheese. The device shown comprises a box-shaped housing 2, which in this example comprises a lower and upper hard metal part. The container may be made of metal, for example stainless steel, or a suitable plastic that is airtight. The lower part 3 forms an open container that can be closed with the upper part 4 acting as a lid. The lower and upper parts have suitably shaped matching edges 5 and 6, between which there is a sealing material 7 for forming an airtight closure. A gas-tight flexible wall 8 is placed in the cover, in this example in the form of a flexible membrane that forms a closed air chamber 9 in the upper part of the cover. Alternatively, the air chamber may be equipped with a movable rigid partition or punch. In the context of the present description and claims, the present made example is understood to encompass the term "flexible wall". The cover is additionally equipped with a pipe 10 ending in the air chamber 9 having a suitable working gas valve 11.

[0014] The lower part is similarly equipped with a pipe 12 running through the wall of the lower part, which ends in the inner space 13 of the container and which is equipped with a suitable working gas valve 14.

[0015] The cheese mold 20 can be placed in the container, as shown. To this end, suitable supports 21 can be used if necessary. During operation, the cheese mold 20 is filled with cheese mass 22. It may consist of a pre-shaped a curd block, such as that produced, for example, with a so-called drainer and a curd mold, for example of the Tetra Tebel Casomatic type^® or Tetra Tebel Pressvatic^®, or so-called block molding machines, for example of the Tetra Tebel Blockformer type^®. The cheese mass may also consist of, for example, a fresh granular curd or shredded pre-dried or acidified cheese mass, such as the so-called curd strips, also known as curd chips, from an acidifying device such as the Tetra Tebel Alfomatic type^®, poured into the cheese mold. The cheese mold 20 and associated lid 24 have traditionally perforated walls to escape from the cheese mass through holes in the perforated walls, whey and air. This is indicated schematically by arrows 23.

[0016] Working rests on the cheese mass 22, as usual, the movable lid 24 of the cheese molds. This cover is often called a "pusher."

[0017] During operation, the top of the cheese mold lid adheres to the membrane 8, which delimits the air chamber 9 in the container lid 4.

[0018] The device described above can be used to produce cheese blocks as below.

[0019] After placing the curd-filled cheese vat 20 in container 2 and closing the container, in a first stage using a vacuum pump agent 15 through a pipe

-412 and then the open valve 14, the pressure in container 2 is reduced to the first vacuum. In addition, if desired, depending on the type of cheese, simultaneously through a pipe 10 and then an open valve 11 or through a separate pipe with a valve, a vacuum is created in the air chamber 9 to avoid moving the diaphragm 8 downwards due to the residual air present in this air chamber, and exerting pressure on the cheese mass 22 through the underlying cover 24. The connection of the tube 10 and the means in the form of a vacuum pump and 15 and the valve necessary for this purpose is not shown in Fig. 1. As a result of the reduced pressure around the mold to the cheese, air is also generated from the inside of the cheese mass and through the holes in the walls of the vat for cheese , as indicated by arrows 23. This airflow also grabs whey from the curd. Accordingly, during the first stage air and whey are extracted from the cheese mass.

[0020] During this stage, the valve 11 in the pipe 10 connected to the air chamber 9 may be open or closed. For some types of cheese, it is useful to open valve 11. This can be done immediately at the beginning of the first stage or shortly thereafter. In this case, the air chamber expands so that due to the large pressure difference between the interior of the air chamber 9, where the ambient pressure prevails, and the interior of the container, the flexible membrane 8 is stretched. The membrane 8 thus presses the top of the pusher 24 so that the cheese mass is compressed in the cheese container. In this way, air and whey can be squeezed out of the cheese mass in an accelerated manner.

[0021] To obtain a type of cheese with a completely or virtually completely closed texture (cheese without holes), i.e. cheese without air inclusions or whey, then, preferably, during the second stage, the pressure in the container can be further reduced to a second lower vacuum, such that still existing whey begins to boil if the boiling point has been lowered as a result of the vacuum to the whey temperature. The vacuum depth required for this depends on the whey temperature and can be controlled depending on the whey temperature or cheese mass. The second vacuum may for example be on the order of several tenths of a millibar, for example on the order of 50 millibars. When the whey begins to boil, some of the water contained in the whey evaporates in all the cheese mass containing its core. As a result, the volume of water increases strongly so that all air and free whey are forced out of the cheese mass. The volume increase may be in the order of 35,000, depending on the vacuum.

[0022] If during the first stage the valve 11 was not open, it can still be opened, if desired, after or near the end of the second stage. As already described above, the membrane 8 then exerts pressure on the pusher 24 and the cheese mass in the cheese mold is compressed. The valve 11 then also remains open during the third stage described below.

[0023] In the next step, the vacuum is maintained for a particular time, which depends on the type of cheese and the size of the block of cheese to be produced. If the valve 11 was not open during the second stage, it is now to be opened. As already described above, the membrane 8 then exerts pressure on the pusher 24 and the cheese mass in the cheese mold is compressed. In this third stage, which usually lasts the longest of these stages,

Clot particles may adhere to each other and join together and a stable skin may be formed. Adding atmospheric pressure through the valve can be done in one step, but depending on the type of cheese, it can also be done in many stages. In the first case, the maximum baling pressure is available directly. In the second case, the pressing pressure is built up in stages. For this purpose, air at a pressure lower than atmospheric pressure may be admitted into the space 9. In this way, for example, less compact or shallower skin formation can be achieved. If desired, the final pressure can also be increased by admitting air at a pressure higher than atmospheric pressure. If desired, the maximum pressure force at atmospheric pressure can also be reduced by reducing the membrane surface relative to the cover surface and / or the cheese mass.

[0024] Once the boiling point of the whey is reached, the valve 14 can be closed and the vacuum pump turned off. The depth of the vacuum is then no longer significantly changed. However, it is also possible to keep the vacuum pump on for the remainder of the second stage and if necessary at least part of the time period. The vacuum pump then continues to actively exhale the steam formed by boiling. This promotes further evaporation of water and allows you to remove even more steam. In this way you can control the moisture content of the cheese.

[0025] After the third stage of some skin forming range has occurred, in the fourth stage the vacuum depth is reduced to a value that is higher than the boiling limit. The remaining water vapor condenses in the cheese mass and its volume strongly decreases. The reduction factor is in the same order as the expansion factor indicated in the second stage. A sudden decrease in the volume of steam causes implosion in the cheese mass, as a result of which the cheese mass shrinks internally, so that the cheese mass is additionally compressed.

[0026] The pressing treatment can later be continued by maintaining the vacuum depth for a little more time or gradually reducing it, which may or may not be done gradually. The ironing procedure ends with the removal of the vacuum. The reduction or removal of vacuum can, for example, be achieved by admitting air at atmospheric pressure (ambient air) through pipe 12 and valve 14.

[0027] The block of cheese thus obtained can then be removed from the cheese mold after the cheese mold itself has been removed from the container. If atmospheric pressure is already applied to the surface of the cheese block through the holes in the walls of the cheese mold, while reduced pressure still prevails inside the cheese block, and the condensation of the trapped steam continues, with the initial volume of steam absorbed by the cheese mass, the block of cheese is squeezed and loosely extracted from the cheese mold. As a result, the cheese block extends from the cheese mold walls and can be removed from the cheese mold without conventional aids, such as a vacuum cup or compressed air.

[0028] It is possible to automate the described method. To this end, valves 11 and 14 and vacuum pump 15 can be designed to be controllable, for example

Electrically and connected to a control device 25, e.g. a microprocessor, which controls the valves and the vacuum pump according to a predetermined time schedule and predetermined control settings. Pressure gauges 26, 27 can then also be provided, which, for example, measure the pressure in the space 13 in the container and in the air chamber 9 and which are also coupled to the microprocessor 25.

[0029] An important advantage of the method described is that separate mechanical pressing is no longer necessary. A significant pressure difference, already formed by vacuum treatment, between the environment and the interior of the container can advantageously be used for the pressing procedure. Nevertheless, it is possible, if necessary, to exert the required pressure force fully or partially mechanically.

[0030] Another important advantage is that the pressing operation described takes only relatively little time.

[0031] Based on experience, the described method is expected to take only a small amount of time, for example about 15 minutes for Gouda cheese and comparable types of cheese. It takes only a few seconds for the vacuum to be created during the first stage and the removal of free whey by the impact of steam. What's more, cheese molds no longer require transport to separate mechanical pressing stations.

[0032] In addition, due to the short cycle time, it is easier to monitor and, if necessary, the quality of the final product can be adjusted. Thus, for example in the case of Gouda cheese, the final weight of the cheese block is already known after about 15 minutes, so that if necessary, the setting of the dosing unit defining how much curd is placed in the cheese mold can be changed relatively quickly. This time can be minimized up to tens of seconds if the escaping whey with air and steam will be discharged from the container through the pipe 12 and the open valve 14 and will be separated in front of the vacuum device 15. The mass of the separated whey can be determined and compared with the mass of the curd placed in the mold. cheese. Based on the separated amount of whey, a very accurate forecast of the final weight of the cheese block is possible. This makes it possible to control the dosage of the cheese mass placed in the cheese mold to obtain a cheese block having a predetermined desired mass. Fig. 1 as a schematic representation of a whey separator.

[0033] By adjusting the time during which the vacuum pump lasts during the third stage, it is also possible, if desired, to control moisture content simply and quickly.

[0034] In addition, it has been found that, by using the method of the invention, the chance of air or whey inclusions in the cheese being produced is much less than with existing methods. It has also been shown that the method according to the invention is not very susceptible to widespread cheese defects in known production methods, resulting, for example, from any time disturbances or clumping of part of the curd.

[0035] Finally, the quality of the whey released is relatively high, because it is collected directly in the container and remains in it only for a short time. Whey can stay

-7 processed in this way more quickly and cannot come into contact with parts of the mechanical pressing device.

[0036] Fig. 2 schematically shows, for the sake of completeness, an exploded perspective view of an example of a practical container design for applying the method of the invention. The reference numbers used in Figure 2 correspond to those for the corresponding parts in Figure 1.

[0037] In the exemplary embodiment shown in Fig. 2, both the container 3 and the lid 4 are equipped with circumferential reinforcing rib 30 and 31, respectively. The reinforcing effect is also externally bent edges 5 and 6. In addition, in this example on the upper wall 32 of the cover 4, the reinforcing ribs 33, 34 are provided in the form of a cross.

[0038] The cover in this example, equipped with a pipe 10 with a gas valve 11, is additionally equipped with a second pipe 35 with a controllable valve 36, through which, if necessary, a vacuum can be created in the air chamber 9.

[0039] The flexible membrane 8 in the example shown is equipped with a mounting edge 37 for mounting the membrane in the cover 4. If desired, the mounting edge can be designed so that it can slide up and down in the cover up a limited distance. The pusher 24 has traditionally located on the outside of the cheese mold plate 38, which is connected through partitions 39 to a pressing platform 41 equipped with perforations 40.

[0040] The container 3, equipped with a vacuum pipe 12 containing a gas valve 14, is additionally equipped with a second pipe 42 containing a working gas valve 43 to allow for a quick supply of ambient air or, if necessary, compressed air into the container interior space 13.

[0041] In the container 3, a cheese mold 20 is placed having perforated walls fitted in a traditional manner with holes 44. The cheese mold in this example is equipped with ribs 45 functioning as spacers that prevent the cheese mold from moving inside the container.

[0042] It is worth noting that on the basis of the above, many variations or modifications of the described device will easily come to mind those skilled in the art. Thus, the flexible membrane in the cover could, for example, take the form of an inflatable balloon attached to the cover only in the vicinity of the balloon opening. Pipes 10 and 35 should then end within the opening.

[0043] The container itself could also consist wholly or mostly of a flexible, stretchable and non-stretchable airtight material. An example of such a container is outlined in Fig. 3. Fig. 3 again shows the cheese mold 20 with the pusher 24 and the cheese mass 22 in the cheese mold. The cheese mold is placed in a balloon-shaped container 50 of flexible air-tight material, such as plastic film.

[0044] The balloon 50 is equipped with a connection 51 for a vacuum pump and a connection 52 for air supply. The vacuum connection 51 is equipped with a suitable valve 53 and the air connection 52 is equipped with a valve 54. If a balloon is created in the balloon 50, with the valve 54 and valve 53 open, a flexible material of the balloon 50 will adhere to the cheese mold and exert pressure on the pusher. As a result, the cheese mass 22 is compressed. Vacuum can be removed quickly by opening the valve in the air connection or even supplying compressed air. The balloon should have a sufficiently large access opening to allow the cheese mold to be placed in the balloon or removed from there. The access opening may for example be formed by a flap that can be opened or closed. The cheese mold should furthermore be at least partially double-walled to prevent the flexible material from closing the walls 44, which would prevent whey and air from escaping from the curd. Such double walls are shown in Fig. 3 as 55. Alternatively, a wall with internal air and whey channels can be used.

[0045] The exemplary embodiments of devices not according to the invention shown in the drawing are prepared for receiving a single cheese mold or a single mold for many cheeses, but of course the container can be designed simply so that several cheese molds can be treated in it simultaneously. .

[0046] Furthermore, as already noted, a cheese mold having a movable bottom or side wall (s) can be used. The container of hard material should then have an adapted form with one or more gas-tight closing side walls or gas-tight closing bottom or parts of the side walls or bottom through which the container can be placed and the cheese mold can be removed from the container.

Dorota Rzążewska Patent attorney