In an ideal world, all solids in the cheese vat would end up in the finished product. Unfortunately, this is not possible with our current cheesemaking methods. Therefore, cheese yield has become a way to define the percentage of moisture, casein and fat in milk that actually converts into cheese. Since high retentions of moisture, casein and fat equal a high cheese yield and high economic gain, the goal is to retain as much protein, fat and moisture as possible, while ultimately producing a cheese with the desirable quality attributes.
A cheese yield prediction equation describes the relationship between the concentrations of fat and casein in milk and the amount of cheese that can (in theory) be produced from that milk. This prediction equation includes factors for fat recovery and casein losses, as well as the retention of other solids like whey proteins and salt. Although the calculation is quite simple, reaching that optimum cheese yield and retention rate is not.