Chhurpi or Durkha is hardened cheese consumed mainly in the Himalayan region of Nepal and Tibet. There are two main varieties of Chhurpi; the soft variety prepared out of cow's milk and the hard variety prepared out of yak's milk. Chhurpi is made by separating whey from buttermilk solids to produce curds similar to Italian Ricotta. Fresh curds are white, soft and neutral to taste, but they are left to ferment to acquire a bit of tanginess. Soft Durkha or Chhurpi is an excellent source of protein and is used as a substitute for vegetables in the mountainous region. A curry and/or pickle are made of Chhurpi and are eaten with rice as a staple food in everyday meals. Chhur singba or Chhur mingba is freshly prepared Chhurpi prepared by adding the extract of crab apple fruits (thung).
Hard Durkha or Chhurpi is made out of yak milk. After the curds are cured at room temperature for 2-3 days, the cheese is sliced and left to dry in the sun or dried in the oven on low heat, which makes Chhurpi very hard and lasts many years. If hard Chhurpi is as old as 4 to 5 years, it is called chhurpupu. If stored properly in yak skin (mongnang), hard Chhurpi can be consumed even for 20 years.