Dushan chousuan

A sour with its own place

Dushan chousuan, 臭酸, is a pungent fermented vegetable condiment associated with Dushan County in southern Guizhou. Its name means stinky sour: the smell and the acidity both matter to its identity. A study of market samples describes a green, sticky product used to season meat, tofu and hot pot. A small amount of this concentrated preparation can enter a cooked dish, while a restaurant may also serve the sour uncooked as a condiment.

The county has several named sours. The Dushan study groups stinky sour with shrimp sour and yan sour as three regional fermented foods. Sharing a name for sourness does not make their ingredients interchangeable. Chousuan is the vegetable preparation described here; shrimp sour is a separate seafood preparation. The sources do not establish when chousuan was first made or identify a single inventor.

The plant and the other ingredients

The Dushan study names its main plant impatiens, Impatiens balsamina L. Garden balsam is the English name given in the filmed visit. The study provides a relevant scientific identification for its described traditional ingredient, but the footage and captions do not independently identify the plant in that particular workshop. Nor does the paper specify which parts of the impatiens plant are used. The plant name alone is not a basis for selecting or gathering a plant for food.

The paper also names mustard greens, Brassica juncea L.; bamboo shoots; pungent litse fruit, Litsea pungens Hemsl.; and fried wheat. It describes makers adjusting their ingredient ratios. These are ingredients of the traditional pattern the researchers report; the paper does not give a weighed formulation or establish the composition of each of the 42 individual samples. It calls the litse material fruit, so the more familiar translation seed should not be substituted without evidence about the material a maker uses.

The named ingredients contribute different materials to a mixture rather than forming a simple single-vegetable pickle. The paper records the aromatic litse fruit and fried wheat as additions, but does not measure what each one contributes to fermentation or quantify its share. In particular, fried wheat is not evidence of an added microbial starter. The authors describe the fermentation as natural, with no starter introduced.

How the reported preparation is made

The researchers describe washing and draining the impatiens and greens, cutting them, and combining them with chopped bamboo shoots, fried wheat and litse fruit. The mixture is packed and compacted into pottery jars, which are sealed and kept in the shade for natural fermentation. Their general account gives approximately one month and says ratios vary with the maker. It cites an earlier review for the method; the original review was not inspected for this draft.

This is a description of an established practice, not a complete reproducible batch. The paper does not provide ingredient weights, the plant parts, a salt quantity, an actual temperature range, a measurement-based endpoint or a validated storage period. Shade describes where the jar is kept; it does not specify a temperature. Approximately one month is the authors’ reported duration, not a universal safety threshold. These omissions matter when attempting to reproduce the food, and a measured method and qualified process assessment are needed before turning the description into home instructions.

The physical stages still explain the form of the food. Cutting makes pieces that can be packed together, while compaction places the mixture inside the vessel before the long fermentation. The finished material has a sauce-like consistency; the sampled market products were green and sticky. Neither a particular colour nor a strong smell establishes that an unknown batch is suitable to eat.

What the study measured

The researchers bought 42 chousuan samples from Dushan agricultural markets in February 2023. They measured acidity and microbial counts, sequenced bacterial and fungal marker regions, and used electronic nose and tongue instruments to compare the samples. The samples varied in microbial composition and in sensor responses. This snapshot shows diversity among products available at the time; it does not trace every jar from fresh ingredients to completion or establish a recipe for all local makers.

Lactic acid bacteria were among the organisms detected, and the authors discuss their potential relationship with sourness. Sequencing reports the genetic signatures found in samples; it does not by itself show which organisms were active at each stage or prove that any one organism caused a particular flavour. The researchers also found statistical associations between microbial groups and electronic taste or aroma readings. Those correlations suggest questions for experiments rather than proving that adding or removing a named culture will reliably change a batch.

The electronic nose had a strong response from a sensor sensitive to sulfides; the paper also notes that this sensor responds to nitrogen oxides. It does not identify a particular odor molecule by that measurement alone. Across the sampled products, acidity and microbial counts had negative associations. Those observations are useful for understanding variation, but they are not a tested safety limit, a home fermentation target, or a substitute for knowing the raw materials and process.

At the table

In the filmed Dushan restaurant visit, the finished sour appears in two different dishes. One is described as raw, with chilli and tomato. The speaker is uncertain whether the crunchy addition is peanut or toasted soybean; the caption should not be silently changed into a confident statement that both are present. Whole mujiangzi are also mentioned. The transcript does not give amounts or a full restaurant recipe.

The second dish is the sour cooked with pork large intestine. The speakers describe it as stir-fried, and their reactions indicate a less dramatic taste than the raw serving they had just tried. That is a comparison made by those diners, not a guarantee that heating removes the smell or makes a batch safe. The study’s mentions of meat, tofu and hot pot offer other examples of culinary use, without providing separate recipes for them.

The raw dip and the cooked dish begin with a prepared sour. Chilli and tomato in the restaurant serving cannot automatically be read back into the original fermentation. Likewise, the transcript’s discussion of rice-based white sour and chilli sour concerns other preparations. A tomato sour soup study describes its own tomato, rice-flour and liquor tradition; its formulation is evidence of that different sour, not a missing ingredient list for chousuan.

Reading the evidence

The strongest subject-specific evidence here is the Dushan market study and the observed restaurant descriptions. The first provides a named set of ingredients and a general account of fermentation, plus measurements on finished samples. The second shows how diners encountered the sour but does not reveal how its particular batch was prepared. These sources support a substantial account of the food and its uses, while leaving an exact method unresolved.

A separate regional Chinese account appeared in search results but could not be opened, so its reported alternatives and timing are not incorporated as verified instructions. Further work should inspect a maker’s full method and identify the food plant and its parts in that context. A dependable recipe would also need its quantities, handling, fermentation conditions, endpoint and storage assessed together. Until then, this entry records the practice without pretending that its missing measurements can be reconstructed from a photograph, an aroma, or a different sour.