Cream made from whey, used to make a very low-calorie butter
In the past, the combination of polenta and Brossa was a typical meal for mountain pasture shepherds, because it was highly nourishing and rich in calories, which provided the energy required for a hard day's work. Today, it is considered a pure delicacy, which can be enjoyed in country guesthouses or local restaurants offering typical menus from Valle d'Aosta cuisine.
Brossa is a ‘cream’ made from heated whey, to which vinegar (or something just as sour), thus allowing the fat and small quantities of protein to rise to the surface. Brossa is used to make fine butter, which contains fewer calories than butter made with cream.