Grana Padano PDO cheese is produced with milk from cows that have been fed on fresh forage, hay, corn silage or preserved fodder.

Grana Padano is produced with raw milk to which rennet, lysozyme and salt are added.

Silage is a traditional technique of fodder conservation typical of many areas of the Pianura Padana (Po River Valley) in Northern Italy, mainly used for whole maize/corn plants which are placed in special trenches where, following proper compression and air free conditions, natural acidification occurs. This fodder technique is part of the Grana Padano production traditions and enjoyed by cows.

In the preparation of preserved foods, hay or silage, a critical aspect is the possible contamination with soil that may contain bacteria such as Clostridium tyrobutirricum. If present in the silage, this bacterium can find favourable conditions for multiplying and passing in to the milk.

The milk produced for fresh milk, even of high quality, or to make soft cheese, comes from cows which are often fed with silage/preserved fodder, but clostridia need time to mature, so they haven’t got the time to develop in fresh milk or soft cheeses.

The milk for the production of Grana Padano PDO cheese is partially skimmed by natural surfacing of the cream and, during this process, most of clostridia are eliminated, but some of these microorganisms may remain in the milk and find the conditions to develop during the long ageing of the cheese and, after a period of time, abnormal fermentations may occur that compromise the cheese and its quality.

To control the negative effects of the Clostridium Tyrobutirricums’ development, lysozyme is added to the milk.

Lysozyme is a naturally occurring protein, extracted from egg white, and is also present in high quantity in breastmilk, in tears and human saliva.