Hay milk
Milk from animals fed fresh grass and hay but no silage, protected in Europe as a traditional speciality.
Also: Heumilch, latte fieno, lait de foin
Hay milk comes from cows, sheep or goats that eat grass and herbs in summer and dried hay in winter, but never silage, the fermented fodder common on modern farms. Alpine cheesemakers have long refused silage because it can carry spore-forming bacteria that survive cheesemaking and cause wheels of hard cheese to crack and swell months later, a fault called late blowing. Comté, Gruyère, Emmental and Parmigiano Reggiano rules ban silage for this reason. Since 2016 Heumilch, or hay milk, has been registered in the European Union as a traditional speciality guaranteed, led by Austrian farmers. Hay milk cheeses can use raw milk safely without additives.