🪭 Rushan

Rushan (乳扇, “milk fan”) is a dried cow's-milk cheese made in thin sheets, a traditional food of the Bai people of Yunnan province in south-western China, above all in Dali prefecture. The Bai have made it for centuries, and it is one of China's five traditional acid-curd cheeses. ¹²⁶

Where it is made. Most Bai live in Dali prefecture, around Erhai Lake. Dairy cows graze the wetter meadows near Dengchuan and Eryuan, and rushan is made in Eryuan, Dengchuan, Xizhou and other places. ⁶ Studies sampled cheese from Weishan, Eryuan and Jianchuan counties; local Dengchuan cattle give milk rich in fat and protein. ¹

When it began. Written records are rare. The Dengchuan Gazetteer says rushan was already made in the Ming dynasty, and a list of local goods from 1641 names cheese with a word meaning “milk thread”. The gazetteer adds that a family with four cows could make 200 sheets a day, about as many as today. A legend from the time of the Nanzhao kingdom tells of a farmhand who by mistake poured fresh milk into heated sour milk and saw it set. ⁶

How the milk is curdled. No rennet or starter is added: acid curdles the milk. It is usually soured whey from the previous batch, household vinegar or sour milk; in one study it was a decoction of Chinese quince (Chaenomeles sinensis). The mixture is heated to about 70 °C and stirred with chopsticks until the curd sets. Microbes from the milk, the air, the utensils and the hands do the rest. ¹³⁶

Stretching and drying. The warm curd is kneaded by hand, stretched and wound onto a frame of two bamboo poles about 2.5 m long, set 10 cm apart. In villages the sheets dry for about a day on a covered porch; in one study they dried a day outdoors and two more days indoors. ¹⁶ The finished sheets are 30–40 cm long and 7–10 cm wide, creamy yellow, shiny, hard but pliable, and are sold stacked in pairs. ⁶

Microbes and whey. The same milk and the same method gave different bacteria in different counties: lactic acid bacteria of the Lactobacillaceae family made up 84% in Weishan cheese, while in Jianchuan Moraxellaceae dominated with 66%. ¹ Whey is up to 90% of the milk's volume, about 16,000 tonnes a year, so scientists are looking for uses for it. ²³

Rushan and rubing. The Bai make two cheeses. Rubing, traditionally made from goat's milk, is curdled with a sour plant extract, pressed in cloth and kept as a block, while rushan is pulled into thin strips and dried. Rushan is made from fresh cow's milk, never goat's milk, and one account names household vinegar or sour milk as the curdling agent. Its fresh curds melt in strings much like mozzarella. ⁶

How it is eaten. Before cooking, dry rushan is softened under a damp cloth for 20 minutes. Most often it is deep-fried: the cheese puffs up and turns light and crispy. It is also grilled on a stick and spread with rose jam, eaten raw, or stir-fried with Yunnan ham and vegetables. ⁴⁵ It is part of the Bai three-course tea, which goes back to the Nanzhao and Dali kings: the first cup is bitter, the second is sweet with rushan and brown sugar, and the third is flavoured with honey, ginger and pepper. ⁴⁶

Rushan or mozzarella? Rushan is sometimes called the “mozzarella of the East”, because its fresh curds melt in strings much like mozzarella. The similarity ends there: mozzarella is eaten fresh, while rushan is curdled with acid instead of rennet, stretched into thin sheets about 30–40 cm long, dried and usually eaten hot. The Bai make a second cheese too: rubing, traditionally from goat's milk, pressed into a block, whereas rushan is made only from cow's milk.

There is no protected label for rushan, so go by the name on the pack: “rushan”, the Chinese 乳扇 or “milk fan”. Look for thin sheets about 30–40 cm long and 7–10 cm wide, creamy yellow, shiny, hard but pliable, often sold stacked in pairs. It is sold in Chinese and Asian supermarkets and by specialist importers. Studies give no exact shelf life, so keep it dry and sealed.

Why it matters to you. Rushan is a dried product, but studies do not give an exact shelf life, so keep it dry and sealed. In articles you may see “blood-pressure-lowering peptides”, but these come from laboratory experiments with whey, not proof that the cheese itself is good for you. Unlike mozzarella, rushan is dried in thin sheets and usually eaten hot. ²