Improvements relating to cheese making

Abstract

A method of hard-cheese curd production in a vat, a method of controlling the amount of curd material formed in a hard-cheese curd production in a vat, and a method of controlling the final amount of

Description

IMPROVEMENTS RELATING TO CHEESE MAKING The present invention relates to methods of hard-cheese curd production, for forming a curd for the subsequent manufacture of a hard cheese, as well as to curd formed by such methods and cheese products formed from such curds. Field of the Invention Cheese is a food derived from milk that is produced wholly or substantially by coagulation of the milk protein casein. The milk comes usually from cows, but also other animals such as buffalo, goats and sheep. Typically, the milk is acidified and then coagulated by the addition of rennet. Curd is the product obtained by the milk coagulation, and the process is sometimes called ‘curdling’ or maturation. The solids formed in the curd are separated and pressed into a final form, and various differences in the milk, ingredients, timing, separating and pressing provide the varieties of the cheeses known. Casein is the name for a family of related phosphoproteins, which typically make up 80% of the proteins in cow’s milk. Casein contains a high number of proline residues which do not interact, so that the casein can be held as a suspension in milk. The addition of an acid to the milk reduces the milk’s pH to allow the proteolysis of the casein to occur, typically catalysed by the addition of a suitable enzyme, which leads to the ‘de-suspension’ and formation of the solids in curd. The enzyme used in most cheese making is rennet, containing a proteolytic enzyme and typically obtained from the stomach of calves or other sources such as microbial Rennet is available in different ‘strengths’, one measurement of which is the ‘International Milk Clotting Unit, or ‘IMCU’ per millilitre. The common expression used for a thousand IMCUs is ‘MIMCU’. Curd is typically made in ‘vats’. A conventional size of an industrial curd vat is 22,000 litres, although some variation is known, typically in the range 20,000 to 25,000 litres. Based on experience, the cheese producer then adds their ‘standard’ amounts of enzyme and starter culture. For example, for a 22,000 litre vat, starter culture is typically added in the range 500g to 1000g, and rennet typically added in the amount of 2 kg for the ‘standard IMCU / mI 600 strength rennet’, which equates to 1.2 MIMCU per vat. Whilst variations in the curdling and subsequent cheese making provide the variety of known cheeses, a range of cheeses are known as ‘hard’ cheeses, and a particularly major industrial and commercial product is ‘cheddar cheese’, generally provided by reducing the level of moisture in the curd through the ‘cheddaring’ technique or process. This generally involves repeatedly cutting or milling the curd a number of times to extract or push away moisture, in particular remaining whey. Meanwhile, milk quality also changes from farm to farm, and throughout the year, for example depending on what the animals are eating, in particular between summertime when cows are typically eating fresh grass, and wintertime when cows are typically indoors eating hay and other winter fodder. As such, there is seasonality in the composition and the ratios of the components in milk, even from the same cow or the same farm. This traditionally leads to variability in the nature of the final cheese, and variability in the production thereof. Furthermore, cheese producers typically obtain their milk from a ‘pool’ of farmers, and ‘pool’ such milks into large silos which do not necessarily create a mixed or homogenised output to curd-making vats. As such, there are no clear figures in the art for the composition and the ratios of the components in curd-making milk to account for the variations that occur. For example, the level of protein in the milk from the casein and whey portions, is currently only assumed to be a fixed percentage of the milk content. Such seasonality and other variations in the starting milk are well known in cheese production, but once the ‘industry standard’ amounts of enzyme and starter culture are added based on the expected milk composition, the maturation process is still currently only judged by an experienced human tester tasting and touching the curd, to determine if maturation is complete, or if the curd production should continue. Furthermore, the total curd output is also only known at the end of the curd maturation. It is an object of the present invention to provide improvements relating to cheese making, and in particular to provide methods to help regularise the maturation rate of curd production, and to reduce the effect of seasonality on cheese milk and cheese yield. Summary According to one aspect of the present invention there is provided a method of hard- cheese curd production in a vat from at least two different milks comprising the steps of (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; (d) measuring the casein content in the combination of the first and second milks either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd. According to a second aspect of the present invention there is provided a method of controlling the amount of curd material formed in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk: (d) measuring the casein content in the combination of the first and second milks, and either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd. According to a third aspect of the present invention there is provided a method of controlling the final amount of casein in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; (d) measuring the casein content in the combination of the first and second milks, and either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd. According to a fourth aspect of the present invention there is provided a curd whenever formed by a method as defined herein. According to a fifth aspect of the present invention, there is provided a cheese product obtained from a curd whenever formed by a method as defined herein. Detailed Description A general description of the present invention, along with examples and accompanying data, will now be provided by way of example only, including: Figure 1 is a flow chart of a method of the invention. The present invention provides improvements relating to cheese making, and in particular to provide methods to help regularise the maturation rate of curd production, and to reduce the effect of seasonality on cheese milk and cheese yield. As mentioned above, cheese is a food derived from milk that is produced wholly or substantially by coagulation of the milk protein casein. The milk comes usually from cows, but also other animals such as buffalo, goats and cheese. The milk is acidified and then coagulated by the addition of an enzyme and starter culture, the most common one being rennet for forming hard cheeses such as cheddar. As mentioned above, casein typically makes up 80% of the proteins in cow's milk. However the amount of casein in cow's milk is variable, depending upon many factors. Typically, the most variable factor is the season of the year. Cows in summer eat a different product than cows in winter, which therefore affects the amount of casein in the final milk. However, casein levels in milk is conventionally treated as being “80%” without further consideration. After new and detailed analysis by the inventors, the amount of casein can vary from a high value of 2.7wt% or more in the winter, down to below 2.6wt% or below 2.5wt% or even lower during the summer. This also creates variation in the proportion of the total protein content in milk being casein, typically varying between 76% and 82%. This variation in the content of the casein in the milk is one of the major factors in variation in the production of curds and cheese, that has hitherto simply been accepted by conventional curd producers as a necessary and accommodatable factor in curd production. Milk from farmers is typically collected in tanker lorries (‘milk tankers’), delivered to a curd production site, and transferred into large silos of milk. The term ‘silo’ as used herein relates to a storage container comprising at least 50,000 litres, typically more than 100,000 litres, such as 125,000 litres. However, not only is there the variations discussed above, but different deliveries of milk are not necessarily fully mixed in the silo to produce a ‘homogeneous’ volume. Thus, any ‘sample’ of the milk in a silo can only be an estimate of a larger volume of the milk in the sample. Moreover, milk is an organic product, whose composition can vary over time, such that a sample analysis on one day may change on another day. The curd so produced may then be stored for a period from 5 to 700 to 800 days depending on the maturation level required and as such, a curd and cheese manufacturer currently makes estimates of the milk composition used in curd manufacture, and relies upon human testing to decide when maturation of the milk has occurred before the next stages of production. As such, curd (and cheese) making has, since time in memorial, relied upon human expertise to consider when maturation is finished. According to one aspect of the present invention, a method of hard-cheese curd production in a vat comprising the steps of: 101: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; 102: (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; 103: (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; 104: (d) measuring the casein content in the combination of the first and second milks, and either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; 105: (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd. By accurately measuring the casein content in the vat, a consistency can be achieved of the maturation of the curd-starter material, and thus made more consistent Optionally, a method as claimed in any of the preceding claims wherein the casein content in the vat is maintained at a consistent value, said value being a value in the range 23wt% to 33wt%. Optionally, a method as claimed in any of the preceding claims wherein the casein content in the vat is maintained at a consistent value, said value being a value in the range 23wt% to 27wt%. Examples of said values are 23.5wt%, 23.75wt%, 24wt%, 24.25Wt%, 24.5wt%, 24.75wt%, 25wt%, 25.25wt%, 25.5wt%, 25.75wt%, for full fat hard cheese. Optionally, a method as claimed in any of the preceding claims wherein the casein content in the vat is maintained at a consistent value, said value being a value in the range 26wt% to 33wt%. Examples of said values are 26wt%, 26.5Wt%, 27wt%, 27.5wt%, 28wt%, 28.5Wt%, 29wt%, 29.5wt%, 30wt%, 30.5wt%, 31wt%, 31.5wt%, 32wt%, 32.5wWt%, to 33 wt%, for reduced fat hard cheese. Furthermore, by accurately knowing the casein content in the vat a better consistency can be achieved in the casein:fat ratio, further leading to better control and consistency of maturation of the milk. If the Total Protein:Casein:fat measurements are known they can be related back specific density measurements of the two milk streams which are then used to control the mix ratio between the first and second milks Optionally, the casein:fat ratio is maintained at a consistent value, said ratio being a ratio in the range 1.069 to 1:1.47. The ratio is the ratio of casein content as a wt% to the ratio of fat content as a wt%. Optionally, the casein:fat ration is maintained at a consistent value, said ratio being in the range 1:1.33 to 1:1.47 for full fat hard cheese. The ratio is the ratio of casein content as a wt% to the ratio of fat content as a wt%. Optionally, the casein:fat ratio is maintained at a consistent value, said ratio being a ratio in the range 1:0.69 to 1:1.11 for reduced fat hard cheese. The ratio is the ratio of casein content as a wt% to the ratio of fat content as a wt%. The above methods reduce the effects of seasonality of the milk, and thus provide consistency and standardization of the maturation rate of the curd. With such control, the curd producer can then seek to optimize the throughput of the vat, by having knowledge of the final protein content of the curd. Thus, not only does the present invention assist to reduce the effect of seasonality on curd-starter materials such as milk, but can also help increase the production of curd, and / or decrease waste in the production of curd. For example, by knowing and achieving a casein content in the vat being at a pre- determined total value (from only estimated milk starting materials), the curd producer can then calculate the total casein the vat, and the total casein and protein content of the maturated curd, and therefor the throughput of the vat. This allows the curd manufacture to predict production rate, and if desired, to maximise the production rate consistently. Optionally, the first milk is a skimmed milk. The term “skimmed milk” as used herein refers to a milk having a fat content being less than 0.1% fat Optionally, the second milk is a full fat milk. The term “full fat milk” as used herein refers to a milk having a typical fat content being 3.5 to 5.5% (depending on season point in lactation of the cow and breed of cow) Optionally, the second milk is a full fat milk. The term “full fat milk” as used herein refers to a milk having a typical fat content being 4.0 to 4.5% (depending on season point in lactation of the cow and breed of cow) A casein content of milk can be measured using near infra-red technology known in the art. Careful measurement of a sample of a mixed product against accurate calibration samples provides a truer measurement of casein content than sample- testing of an unmixed silo of milk. Further, specific measurement of casein content overcomes any issues with measurement of ‘total protein’ content of milk, which has a range of other variables to be considered, not least the percentage casein composition. Curd is typically made in ‘vats’. A conventional size of an industrial curd vat is 22,000 litres, although some variation is known, typically in the range 20,000 to 25.000 litres. According to one embodiment of the present invention, the fat content in the vat is adjustable by varying the content of the vat. For example, a curd producer may start with 22,000 litres of milk with a certain fat content, but by adding more milk or less milk, with a higher or lower fat content, the overall volume of milk in the vat changes, but the casein fat ratio or the casein content in the vat is a consistent value Milk is a well-known product from cows, but is also derivable from other animals, such as buffalo, goats and sheep, which are well known to also produce a range of hard cheeses. Typically, the rennet used comprises bovine chymosin, optionally the rennet used is a fermentation-produced or genetically engineered rennet, such as CHY-MAX®, CHY-MAX®M, CHY-MAX®EXTRA or CHY-MAX®PLUS (available from Chr.Hansen, Hoersholm, Denmark), optionally a M200 or M1000 product. The same methodology can also be used for novel microbial rennet a small yield adjustment when using other rennet’s will be required. Optionally, the rennet is provided in the range 0.5 to 1.0 MIMCU per vat or per 20,000 — 25,000 litres of curd material. More optionally, the rennet is used from one of a lower range of 0.5, 0.6, 0.7 or 0.8 MIMCU per vat, and from one of an upper range of 1.0, 0.9, 0.8 or 0.7 MIMCU per vat or 20,000 — 25,000 litres of curd materials. Starter materials used in cheese making are generally based on mesophilic and / or thermophilic strains, often being blends thereof to take advantage of the scald temperature used in Cheddar manufacture, (which is normally greater than 38°C). This also increases the activity of the starter, enabling reduced inoculation rates. One range of starter cultures known in the art are termed ‘RSF starter cultures’, and optionally the starter culture is a RSF 900 starter culture, such as RSF925, 940, 945, 950 and 960. Optionally, the starter culture is used in the range 400g — 1000g per 20,000 — 25,000 litres of curd materials. More optionally, the starter culture is used in the range of 450g — 600g, such as 500g, per 20,000 — 25,000 litres of curd materials. Optionally, the enzyme and starter culture ranges defined herein relate to 22,000 litres of curd materials. Optionally, the curd cheese-making product is for making a hard cheese. Optionally, the curd cheese-making product is for making cheddar cheese. Other typical ingredients in the curd cheese-making product include: cheese, milk and salt. The curd cheese-making product generally has: Moisture <38% Salt 1.4-2.2% According to another aspect of the present invention, the process provides a cheese product obtained from the cheese making product as defined herein. According to another aspect of the present invention, the present invention provides a process for making\ a cheese product comprising maturing a cheese making product as defined herein, such as a hard cheese such as cheddar cheese. Example From a first silo of skimmed milk having the composition 2.8 to 2.5 % casein and 0.05 to 0.07% fat and from a second silo of full fat milk having a composition of 2.7 to 2.5 % casein and 4.0 to 4.5% fat it was estimated that a pre-determined casein content in the vat was set at 2.6%. With 2.6% casein in milk in the vat, the curd producer can scale this to a total of amount of casein in a 22,000 litre vat. By controlling the casein to fat ratio in the vat, the curd producer can then achieve a fixed cheese protein (casein) level of 25%. At 2.6% casein and 25% protein in the cheese, knowing these values the curd producer can accurately predict a resultant tonnes of cheese per vat., and throughput through the plant. The present invention thereby provides a method of controlling the amount of curd material formed in a hard-cheese curd production in a vat, and a method of controlling the amount of curd material formed in a hard-cheese curd production. In this way, the curd producer achieves a method of maximizing the throughput of a vat. Moreover, the curd producer is therefore able to match is able to regularly and consistently match the production capacity of the curd per vat, and thus achieve a better economic production, whilst reducing and / or avoiding the affect of seasonality of curd-starter materials such as milk on the final curd yield. In particular, the skilled user can optimise yield, and provide consistency, in the making of curd and cheese, in a manner not yet achieved. In particular, consistent output throughout the year can be achieved, including achieving a production consistency in advance (by being able to predict the final amount of casein at curd maturation), that reduces or avoids the need for human analysis and intervention, in the traditional manner.

Claims

CLAIMS 1. A method of hard-cheese curd production in a vat from at least two different milks comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk: (d) measuring the casein content in the combination of the first and second milks either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd.

2. A method as claimed in claim 1 wherein the pre-determined total value of casein content in the vat is a value in the range 23wt% to 33wt%.

3. A method as claimed in claim 2 wherein the pre-determined total value of casein content in the vat is a value in the range 23wt% to 27wt%.

4. A method as claimed in claim 2 wherein the pre-determined total value of casein content in the vat is a value un the range 26wt% to 33wt%.

5. A method as claimed in any preceding claim wherein the pre-determined total value of casein content in the vat is used to determine a pre-determined ratio of casein‘fat content in the vat 6. A method as claimed in claim 5 wherein the pre-determined ratio of casein:fat content in the vat is in the range 1:0.69 to 1:1.

147.

7. A method as claimed in claim 6 wherein the pre-determined ratio of casein:fat content in the vat is in the range 1:1.47 to 1:1.33 for full fat hard cheese.

8. A method as claimed in claim 6 wherein the pre-determined ration of casein:fat content in the vat is in the range 1:0.69 to 1:1.11 for reduced fat hard cheese.

9. A method as claimed in any one of the preceding claims wherein the first milk is a skimmed milk.

10. A method as claimed in any one of the preceding clams wherein the second milk is a full-fat milk 11. A method as claimed in any one of the preceding claims wherein the hard cheese is cheddar cheese.

12. A method as claimed in any one of the preceding claims wherein the enzyme is a chymosin-derived enzyme.

13. A method as claimed in claim 12 wherein the chymosin-derived enzyme is added in the range 0.4 to 1.1 MIMCU per 20,000 - 25,000 litres of curd-starter material.

14. A method as claimed in claim 12 or claim 13 wherein the rennet may originate from a chymosin-derived enzyme such as CHY-MAX®M or other rennet type.

15. A method as claimed in any one of the preceding claims wherein the starter culture is added in the range 200-800g per 20,000 - 25,000 litres of curd-starter material.

16. A method as claimed in claim 15 wherein the start culture is added in the amount of 500g per 20,000 - 25,000 litres of curd-starter material.

17. A method as claimed in any of the preceding claims wherein the starter culture is a RSF starter culture, such as a RSF 900 starter culture.

18. A method as claimed in claim 17 wherein the starter culture is an RSF 925, 940, 945, 950 or 960 starter culture.

19. A method of controlling the amount of curd material formed in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; (d) measuring the casein content in the combination of the first and second milks, and either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value: (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd.

20. A method of controlling the final amount of casein in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; (d) measuring the casein content in the combination of the first and second milks, and either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd.

21. A curd whenever formed by a method as claimed in any of the preceding claims.

22. A curd as claimed in claim 21 for making cheddar cheese.

23. A curd as claimed in claim 21 or claim 22 having a consistent amount of casein when measured in the vat after step (a), during maturation of the curd-starter material, and at the maturation of the curd.

24. A cheese product obtained from the curd of any of claims 21 to 23.

25. A cheese product as claimed in claim 24 being a cheddar cheese. Amendments to the claims have been filed as follows CLAIMS 1. A method of hard-cheese curd production in a vat from at least two different milks comprising the steps of: 5 (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; 10 (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk; (d) measuring the casein content in the combination of the first and second milks either prior to the vat or once in the vat, and adjusting the final volume of the 15 first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value; (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd. 20 2. A method as claimed in claim 1 wherein the pre-determined total value of casein content in the vat is a value in the range 23wt% to 33wt%.

3. A method as claimed in claim 2 wherein the pre-determined total value of casein content in the vat is a value in the range 23wt% to 27wt%. 25 4. A method as claimed in claim 2 wherein the pre-determined total value of casein content in the vat is a value un the range 26wt% to 33wt%.

5. A method as claimed in any preceding claim wherein the pre-determined total 30 value of casein content in the vat is used to determine a pre-determined ratio of casein: fat content in the vat.

6. A method as claimed in claim 5 wherein the pre-determined ratio of casein:fat content in the vat is in the range 1:0.69 to 1:1.

147. 35 7. A method as claimed in claim 6 wherein the pre-determined ratio of casein:fat content in the vat is in the range 1:1.47 to 1:1.33 for full fat hard cheese.

8. A method as claimed in claim 6 wherein the pre-determined ration of casein:fat content in the vat is in the range 1:0.69 to 1:1.11 for reduced fat hard cheese.

9. A method as claimed in any one of the preceding claims wherein the first milk is a skimmed milk.

10. A method as claimed in any one of the preceding clams wherein the second milk is a full-fat milk 11. A method as claimed in any one of the preceding claims wherein the hard cheese is cheddar cheese 12. A method as claimed in any one of the preceding claims wherein the enzyme is a chymosin-derived enzyme.

13. A method as claimed in claim 12 wherein the chymosin-derived enzyme is added in the range 0.4 to 1.1 MIMCU per 20,000 - 25,000 litres of curd-starter material.

14. A method as claimed in claim 12 or claim 13 wherein the rennet may originate from a chymosin-derived enzyme such as CHY-MAX®M or other rennet type.

15. A method as claimed in any one of the preceding claims wherein the starter culture is added in the range 200-800g per 20,000 - 25,000 litres of curd-starter material.

16. A method as claimed in claim 15 wherein the start culture is added in the amount of 500g per 20,000 - 25,000 litres of curd-starter material.

17. A method as claimed in any of the preceding claims wherein the starter culture is a RSF starter culture, such as a RSF 900 starter culture.

18. A method as claimed in claim 17 wherein the starter culture is an RSF 925, 940, 945, 950 or 960 starter culture.

19. A method of controlling the amount of curd material formed in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk; (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk: (d) measuring the casein content in the combination of the first and second milks, either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value: (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd.

20. A method of controlling the final amount of casein in a hard-cheese curd production in a vat comprising the steps of: (a) providing a first milk having a first fat content in a first silo, and estimating the casein content in the first milk: (b) providing a second milk having a second fat content different to the first milk fat content, in a second silo, and estimating the casein content in the second milk; (c) calculating a first volume of the first milk and a first volume of the second milk required to provide an estimated combined value of casein content, and starting to fill the vat with the first milk and the second milk: (d) measuring the casein content in the combination of the first and second milks, either prior to the vat or once in the vat, and adjusting the final volume of the first milk, the final volume of the second milk, or both, to achieve a casein content in the vat at a pre-determined total value: (e) adding enzyme and starter culture into the vat to achieve maturation of the milk into curd.

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