Milk composition and cheese making - contd...

However, the curd is cooked, to expel moisture at a temperature which normally adversely affects the starter bacteria. The cheese maker must therefore exercise caution to ensure that the desired acid development in the curd is reached at about the same time as the required moisture content.

The defined starter system that is being followed in New Zealand have been based on the temperature sensitivity of the selected strains as well as on their phage resistance and acid producing ability. These defined starter systems have been widely used in U.S and Ireland and are replacing the undefined commercial mixed strain starter cultures, of the type still almost universally used for the manufacture of Dutch type cheese.

If the cooking temperature is kept constant throughout the cheese making year and standardized milk is used, the most important factor by far in producing the cheddar cheese of an uniform and defined quality is the degree of acid production in the cheese vats. To obviate the need to make up for the seasonal changes in milk composition it is normally only necessary to change the percentage of the inoculum of starter so that the required quantum acid is produced.