Byaslag is a simple pressed Mongolian cheese made by curdling fresh milk (cow, yak or goat) with yogurt, whey or a rennet-like agent — traditionally a piece of fermented calf stomach — then draining the curds and pressing them between two wooden boards into a firm white slab that is air-dried. Mild, faintly tangy and sliceable, it is one of the everyday nomadic 'white foods' (tsagaan idee), eaten sliced with milk tea and boortsog, and it keeps without refrigeration.
Byaslag is the fresh pressed cheese of the Mongolian steppe, curdled from cow, yak or goat milk and weighted between boards into firm slabs. One of the herder's 'white foods' (tsagaan idee), it is made in the milk-rich summer and dried for the long winter when fresh milk runs short. The white-food curds split by method: byaslag is pressed fresh, aaruul is the hard sun-dried curd, and eezgii is curd cooked down over low heat until its milk sugars brown and turn faintly sweet.
Byaslag is firm and springy with a clean, milky taste and just a whisper of yogurt tang. Mild and a little squeaky against the teeth, it is good sliced thin with bread or melted slightly with hot milk tea.
The curd can be set two ways. The lactic acid in yogurt lowers the milk's pH toward casein's isoelectric point, where the proteins lose their charge and clump; rennet instead works enzymatically, with chymosin clipping the projecting kappa-casein layer on the casein micelles so they bond into a firmer curd that expels whey readily when cut — ideal for a low-moisture cheese. Pressing the curd under weight drives out the remaining whey and binds it into a sliceable block, and the drier it is pressed, the firmer and longer-keeping it becomes. This pressing is exactly what sets byaslag apart from the other white-food curds: aaruul is hardened by sun-drying and eezgii by long cooking that browns its milk sugars (the Maillard reaction), while byaslag alone is pressed fresh — so it stays the mildest and softest. Its low moisture and acidity let it keep for long periods without refrigeration.
Variations
Yak-milk byaslag for a richer taste, versions with added cream, or fully dried hard pieces for travel.
On the Palate
Where Byaslag sits in the Mongolian flavor cloud
Ingredients
Serves 8How it's made
8 steps · 15 min
- 110 min
Warm fresh milk gently in a pot until hot but not boiling.
- 212 min
Stir in yogurt or tarag and keep on low heat until the milk curdles.
Watch outKeep the heat low and gentle after adding the yogurt — boil it hard and the curd goes tough and rubbery instead of tender.
- 38 min
Continue until the curds clearly separate from the greenish whey.
Watch outYou're done heating when soft white clumps float clear of a thin greenish liquid — that clean split means the curd has fully set.
- 45 min
Line a colander with cloth and pour in the curds to drain.
- 55 min
Gather the cloth and squeeze out as much whey as possible.
- 63 min
Wrap the curd ball and set it between two flat boards.
- 7300 min
Weight it down and press for several hours until firm.
Watch outThe heavier and longer you press, the firmer and drier the block — press it well and it slices clean and keeps for weeks.
- 85 min
Unwrap, slice the white block, and serve or dry for storage.
