Production Process

The raw milk, coming from the geographical area set in the Production Specifications, is partially skimmed by natural surfacing.

This process lasts at least 8-10 hours where fat globules, lighter than milk, form a thick cream by aggregating and getting to the surface, creating a low-fat milk.

1000 litres of skimmed milk are poured inside traditional copper cauldrons (or vats) which have the shape of a bell turned upside down and are used for the process of curdling. Each one produces two cheese wheels, called “twin wheels”.

Then the whey produced in the dairy the day before is added. Naturally full of lactic acid bacteria, it’s the perfect way to trigger the transformation of milk into cheese. The inoculated milk is then brought to a temperature of 31-33°C (88-91°F).

Right after, the rennet is added to the milk and within few minutes the curd is formed.

The calf rennet is added to the milk. The curd is then broken with a whisk (spino) that gradually creates small granular curds, similar to rice grains, which will keep moving thanks to a mixer (rotella).
After turning the steam valve on, the cooking process starts until the temperature reaches 53-56°C (127-136°F).
The curd grains settle at the bottom of the cauldron where they rest for about 60 minutes. During this period the grains aggregate in order to let the cheese form.

A large cheese wheel comes from each cauldron and will be cut into two equal parts in order to create two twin wheels.
Each of the them are wrapped in linen clothes, extracted from the cauldron and placed on a shelf – the spersola.
 

Each wheel is placed into a tight mould and put under the light pressure of a disk, to eliminate the remaining whey and let the cheese harden.
Later the cheese wheel is placed into a cylindric convex mould in order to achieve the traditional rounded shape.

After about 12 hours a plastic band, which carries the marks of origins, is placed between the mould and the cheese wheel (scalzo). The marks of origins consist of: a four-leaf clover with the dairy’s identification number and the province’s acronym, the month and year of production and little rhomboidal dotted lozenges containing the words “GRANA” and “PADANO”.

Then a casein plate, which will become part of the crust, is added on the top face of the wheel. This plate carries a specific ID number, which is crucial when identifying the traceability of each wheel. After 24 hours the plastic mould is replaced with one made of steel characterized by holes and a slightly rounded shape, therefore the wheel will achieve its characteristic cylindrical shape with slightly convex or nearly straight sides and flat, slightly rimmed faces.

Two days later the cheese wheels are soaked in a solution of salt and water.
This step can take from 16 to 25 days at a temperature between 16-18°C (61-64°F) depending on the saline solution, the size of the wheel and the level of salt needed.
The salt adds flavour, eliminates the remaining whey and helps the crust development.

In total, the ageing process can last from a minimum of 9 months to more than 20 months. During this period the cheese will undergo various important physical-chemical changes, from which the cheese will develop its traditional organoleptic characteristics. The aging process guarantees a safe product from the hygienical point of view.
The cheese wheels are looked after, cleaned and turned over about every 15 days, and this work is now done by using special automatic turning and brushing machines.

After 9 months technicians will test each wheel which has to satisfy all the characteristics defined in the specification of Grana Padano PDO. The cheese wheels are examined with traditional tools: a small hammer, a needle and a probe. If needed, technicians can break the wheel.

If the wheel meets the strict requirements according to the Product Specifications prescribed by the Grana Padano Protection Consortium, it will receive the fire-branded mark which certifies its official “Grana Padano PDO” status.