Why Guizhou Needs Sour Soup, and Sour Soup Needs Guizhou | Book Recommendation & Livestream Preview

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Supported by Foodthink’s “Lianhe Creation Plan”, *Fermentation in China: Yunnan & Guizhou* traces ingredients back to their source, guiding readers into Yunnan and Guizhou to explore the region’s rich fermentation culture and traditional fermented foods, and to reveal the diversity and distinct regional character they embody. Beyond outlining the principles of fermentation, the book delves into signature fermented dishes from both provinces, preserving the craft and everyday lives of local artisans through firsthand interviews.

The following excerpt is drawn from the chapter on Guizhou sour soup in the newly released *Fermentation in China: Yunnan & Guizhou*. We thank the author for granting permission.

In Guizhou, the most evocative pang of nostalgia is undoubtedly a ladle of that fiery, tangy sour soup. Sour soup is found throughout Guizhou, but in Qiandongnan Prefecture in particular, it takes centre stage as an indispensable fixture on local tables. “Three days without sour food, and you’ll walk with a limp.” This local proverb encapsulates a Guizhou way of life where nothing tastes right without a touch of sour. It is a staple for everyday meals and equally indispensable during major celebrations—the New Harvest Festival, Dragon Boat Festival, Fishing Festival, Miao New Year, and so on. Across every joyous occasion, the fermented flavour of sour soup acts as a taste that binds communities together.

Guizhou’s sour soup is broadly divided into two types: white sour soup, locally known as rice sour soup, which is brewed from rice or grain cooking water through the fermentation of acetic acid bacteria, lactic acid bacteria, and yeast; and red sour soup, primarily fermented from tomatoes, red chillies, glutinous rice, and other ingredients. Tomato-based brews are referred to as tomato red sour soup, while chilli-based ones go by chilli red sour soup. In some regions, the two varieties are fermented separately, then blended and fermented a second time. Despite their differing ingredients, both red and white sour soups are the product of complex mixed fermentation. The key microbial players are lactic acid bacteria, yeast, and acetic acid bacteria, all of which thrive and develop in anaerobic conditions.

Why did sour soup take root in Guizhou? Why does it thrive here with such enduring vitality? The answer lies in the long history of development and migration of the Miao people. In the distant era of the legendary rulers Yao, Shun, and Yu, the Miao dwelt along the middle and lower reaches of the Yellow River. Repeated military defeats forced them to migrate continually westward and southward, eventually reaching the Jianghan Plain. After a prolonged period of recuperation, the Miao communities settled in the Jingchu region gradually grew in strength. Viewing this rise as a potential threat, King Xuan of the Zhou dynasty “ordered Fangshu to campaign south against the Man tribes.” Later, during the Warring States period, the strategist Wu Qi “conquered the Man and Yue to the south.” Pushed repeatedly by suppression, the Miao ancestors were ultimately forced to embark on their most significant migration. They followed the Wuling Mountains southward into increasingly remote territories, navigating thorny mountain trails and precipitous cliffs, before finally settling on the Yunnan–Guizhou Plateau. In the Qiandongnan region, the traditional Miao migration song *Crossing Mountains and Rivers* recounts this journey: “Enduring a thousand trials and ten thousand hardships, we journeyed westward to forge a better life.”

The ancestors of the Miao people once inhabited the Central Plains and later the Jingchu region. Their culinary traditions were undoubtedly passed down through generations from the Central Plains during the pre-Qin era. Classical records such as the *Rites of Zhou* (specifically the chapter on the Fermented Paste Keeper) already document numerous fermented condiments and preserved foods, indicating this was a commonplace dietary habit at the time. When the Miao ancestors settled in Guizhou’s mountainous terrain, local geography and climate made fermentation an essential technique for food processing and preservation. This practice represents centuries of adaptation between successive generations and their natural environment. Geographically, Guizhou’s plateau is defined by steep mountains and deep ravines. A local shortage of salt, combined with difficult transport routes and exorbitant costs, meant that Miao communities in the region suffered from chronic salt scarcity. Consequently, ordinary Miao households relied on sour preparations made from harvested rice and wild vegetables, using acidity as a seasoning to stand in for salt. Climatically, Guizhou sits on the Yunnan-Guizhou Plateau under a subtropical humid monsoon system: rainfall is heavy, sunshine is scarce, overcast days are frequent, and humidity is high. The organic acids in sour soup are traditionally valued for their ability to aid digestion, whet the appetite, and relieve summer heat.

While modern science can explain the fermentation process behind sour soup, its discovery by the Miao ancestors arriving in Guizhou’s mountains was likely serendipitous. The ancient Miao folk songs act as a cultural encyclopaedia, preserving the roots of countless customs. One ballad honouring their ancestors recounts the origin of white sour soup: according to the myth of Jiangyang, a Miao cultural hero who shaped the world after a catastrophic flood, Jiangyang was bitten by his adversary, the Thunder God. His son journeyed to tend to his wounded father, bringing a bamboo tube filled with rice soup. The trek was so long that upon arrival, the soup had fermented and turned sour. Touched by his son’s devotion, Jiangyang drank it and found it delicious. From that moment on, the Miao people adopted the custom of drinking white sour soup, passing it down through the generations.

While the folk song attributes the discovery to chance, within Miao households, brewing sour soup remains a standard measure of a woman’s diligence and skill. On the hearths of nearly every home in Miao villages, at least one crock sits ready for fermenting white sour soup. The glutinous rice grown by the family is not only the foundation of their livelihood but also the raw material for white sour soup. The method is straightforward: collect the water from washing rice, boil it down to a clear broth, and let it ferment in a crock for three to five days. The process itself is unassuming; the real secrets lie in the water quality and temperature. Fresh spring water from nearby hills or clean stream runoff provides the first guarantee of quality. Placing the crocks on the hearth harnesses the ambient heat from daily cooking, which aids fermentation. The mountain air is damp, teeming with invisible yet vibrant local microbes. These organisms interact with the crocks, exchanging and cultivating together, typically completing the fermentation cycle in around three days. When ladling the soup, utensils must be scrupulously clean and oil-free. Lactic acid bacteria drive the fermentation; any negligence or contamination can cause it to turn rancid, ruining the flavour entirely. When a household’s supply runs low, they might borrow a spoonful of “mother sour soup” from a neighbour to keep the culture alive—a practice that also strengthens community bonds. This unassuming broth is clear and white, tart yet fragrant, rich and deeply savoury with a lingering finish. Day after day, it transforms into the most versatile of flavour bases: vegetables, tofu, beef, fresh fish, pork trotters… virtually anything can be stewed in it. Particularly during sweltering heat, a single bowl brings that familiar tang, instantly calming and refreshing. Radiating outwards from the southeastern Guizhou region, sour soup has become a key to unlocking the province’s distinctive culinary heritage. Local terroir shapes local soup. Though recipes vary slightly, across Guizhou—whether among the Miao, Dong, Shui, or Buyi ethnic groups, and even on Han Chinese dining tables—the vibrant sourness brought by this broth has firmly taken centre stage.

Culinary culture is the finest mirror of its era, and Guizhou sour soup has quietly evolved alongside the currents of history.How did white sour soup give way to its famous counterpart, red sour soup? That calls for the entrance of two key players: the tomato and the chilli. Tomatoes were introduced to China during the Ming Dynasty, but for a long time they were grown merely as ornamental plants. The *Qunfang Pu* (Compendium of Fragrant Plants), compiled in 1621, records: “The foreign persimmon, also known as the June persimmon, has stems like wormwood, stands four or five *chi* (roughly a metre) tall, leaves like mugwort, and flowers resembling pomegranates. Each branch bears three to five fruits, or two to thirty in total. Tied to a trellis, it is most fitting for ornamentation. It comes from the Western regions, hence its name.” The late Qing Dynasty through the Republic of China period marked a crucial era when Chinese people began to embrace tomatoes as food. Attitudes towards them varied greatly across the country, ranging from enthusiasm to scepticism. Yunnan was a pioneer in adopting tomatoes. The 1937 *History of Shiping County* notes that locals once mistakenly believed tomatoes were poisonous, adding, “in recent years, they have become an excellent foodstuff.” For a province like Guizhou, where sour flavours are a daily staple, the arrival of the tomato was perhaps a perfect match. The *History of Majiang County*, published in 1938, describes a method for preserving tomatoes: “pickle them in a jar with salt, garlic, foreign peppers, and sweet rice wine.” This is almost certainly referring to what is now the wildly popular Guizhou delicacy known as “red sour soup.” Chillies only reached China towards the end of the Ming Dynasty. Originally called *fan jiao* (foreign pepper), they first appeared in print in Gao Lian’s *Zunsheng Bajian* (Eight Essays on Nourishing Life), written in 1591 by the Hangzhou native, which states: “The foreign pepper grows in clumps, bears white flowers, and its fruit closely resembles the tip of a worn-out brush. It is pungent, red, and highly ornamental.” At the time, literati and wealthy merchants in the Jiangnan region cultivated it as an ornamental plant. Meanwhile, given its pungent heat, it was also utilised in herbal medicine. By the 18th century, chillies had spread to the south-western region, where they were dubbed “sea peppers.” The *History of Sizhou Prefecture* from 1721 records their presence, noting that they were first valued as a salt substitute before establishing themselves as a food ingredient. Once tomatoes and chillies officially joined the dining table, their brilliant marriage of heat and sourness forged Guizhou’s distinctive spicy-and-sour flavour profile. The long-established white sour soup naturally diverged and evolved, and from the late Qing Dynasty onwards, red sour soup embarked on a culinary legend uniquely its own.

Unlike white sour soup, the preparation of red sour soup is closely tied to local climatic conditions and the harvest cycle of key crops. Starting in September, as red sea peppers and millet chillies ripen in succession, it becomes the ideal season for brewing red sour soup. The finest red sour soup is simmered from local mao la guo (wild tomatoes), a variety prized for its firm, substantial flesh and potent acidity. Combined with salt, distiller’s grains, and chillies, the mixture is sealed in a ceramic jar to ferment naturally. After ten to fifteen days, the lid can be lifted, releasing a rich, intoxicating aroma of fermented fruit. Despite its name, it is far more than mere acidity; it delivers a rich, multi-layered sensory experience. It lacks the sharp bite of fresh fruit or the thin edge of vinegar. Instead, its sourness breathes with a long, rolling depth, weaving through tender, savoury meat before settling warmly in the stomach. In Guizhou, whenever a dish features sour soup, a dipping sauce infused with Litsea cubeba oil is considered its perfect match. Litsea oil, also known as Chinese mountain pepper oil or wild pepper oil, is a distinctive aromatic spice. The fermented tomato juice and rice water form the rich, bright base for the iconic sour soup fish. A touch of Litsea oil, with its gentle peppery lift, rounds out the soup’s flavour profile, creating a seamless and harmonious dining experience.

Fermented China: Yunnan & Guizhou

*Click the cover to purchase the book

Ma Junli & Liu Xinzhen

China Light Industry Press

Published August 2025

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