Yunnan Suanniu Nai (云南酸牛奶)

Suanniu nai — literally "sour cow milk" — is Yunnan's ancient tradition of pot-set yogurt, traceable to the pastoral Tibetan and Bai communities of Dali and Lijiang. Each pottery stall in the Dali old town serves it in small earthenware cups, topped with local rose jam or a drizzle of brown sugar, as a standard breakfast or afternoon snack.

Serves: 4

Ingredients

• 1 litre (4 cups) full-fat whole milk
• 3 tbsp (45ml) plain live-culture yogurt (starter)
• 2 tbsp (30g) brown sugar or rose jam, to serve
• Pinch of salt (optional)

Instructions

1. Pour the milk into a heavy saucepan and heat over medium heat to just below a simmer, about 80°C (175°F) — small bubbles will appear at the edges. Do not boil. Remove from heat and let cool to 43–46°C (109–115°F), about 20 minutes. A drop on your wrist should feel warm but not hot.
2. Whisk the live-culture yogurt starter into the warm milk until fully incorporated. Pour into four small earthenware pots, ramekins, or glass jars.
3. Cover each container loosely with cling film or a cloth. Place in a warm spot (inside a switched-off oven with only the light on works well) for 8–12 hours, undisturbed, until the yogurt is set and pulls cleanly from the sides when tilted.
4. Refrigerate for at least 1 hour before serving — cold setting firms the texture further.
5. Serve in the pot, topped with brown sugar stirred to dissolve slightly, or a spoonful of rose jam.

Cook's Notes: Yunnan rose jam (玫瑰酱) is the traditional topping and worth seeking out in Asian grocery stores. The key to a clean set is keeping the temperature stable during fermentation — drafts or temperature swings will produce a grainy texture.