The cutting of the curd that has been formed after the addition of the rennet is one of the most critical aspects of cheesemaking. Cutting is the start of the dehydration process and will affect the final moisture, acidity, maturation rate and yield of the cheese, all very important factors that distinguish the exact characteristics and quality of a cheese. After the curd is cut it holds the main constituents of the cheese which are the fat and casein plus it also contains some water, minerals, whey, starter culture and rennet. The constituents that are lost in the whey are the water, lactose, whey proteins, some minerals and a small amount starter culture. The term used to describe this loss of these components is called syneresis.
The volume and the amount of these constituents that are either retained in or removed from the curd are very closely related to the surface area of the curd particle after it is cut. The general rule is that the smaller the size of the cut, the greater is the surface area of the curd and the greater is the loss of components into the whey.
To show this: If we started with 1 litre of milk and added rennet so that it formed a cube of curd. We would have a 10cm cube of curd; the surface area would be 600cm cm² (6 sides to a cube). If that cube of curd was cut into 1cm cubes (Cheddar cheese is cut to this size), then we would have 100 cubes with a surface area of 6000cm². If we cut those 1cm cubes into 5mm cubes then we would have 8000 cubes of curd with a surface area of 12,000cm². Simply put the more surface area means more loss of whey and constituents into the whey.
Different cut sizes for a few cheeses may be:
·     Parmesan styles 2 – 3mm
·     Cheddar 8 – 10mm
·     Camembert 12 – 15mm
·     Persian feta very large pieces