Grainy GranaScience Byte
Why is Parmigiano-Reggiano so grainy?
Grana-style cheese refers to Italian cheese with a granular texture, like Parmigiano-Reggiano and Grana Padano. When these cheeses are broken up in the mouth or between fingers their grainy texture is very noticeable.
The primary cause of this texture is due to the use of part-skimmed milk and how the curd is cut and cooked after coagulation has occurred. The lower fat content confers a firmer texture as we mentioned in our post about cheese texture. After rennet addition and coagulation, the curd is cut into tiny rice-sized pieces. These pieces are then cooked at moderately high temperatures. (e.g. 55°C) As the curds are heated and stirred, moisture (i.e. whey) is lost (called syneresis). The smaller size and higher temperature both encourage syneresis.
By the end of the process, the curd grains are rough and relatively dry (compared to other cheese makes). When they are drained and pressed, they retain much of their individual shape/form and have limited cohesiveness with the grains around them. This gives Grana cheeses their distinctive graininess.