Stinky Tofu in Jianshui County

Stinky tofu is the featured snack in Jianshui County.
Smelly tofu is made of high quality soybeans containing high protein, under a series of processes such as immersing, grinding, leaching, halogen treatment, initial fermentation, pickling curing, juicing and final fermentation etc. During the process of initial fermentation to the final treatment, proteins contained in tofu are decomposed by proteases with the sulfur-contained amino acids fully hydrolyzed to form a compound called H2S. That's why the smelly tofu smells stinky. Moreover, with the decomposition of proteins, tasty amino acids will come into being.

Stinky tofu is a form of fermented tofu that has a strong odor. It is a popular snack in East and Southeast Asia, particularly Hong Kong, Taiwan, Indonesia, and Mainland China, where it is usually found at night markets or roadside stands, or as a side dish in lunch bars.

Production of Stinky tofu
Unlike cheese, stinky tofu fermentation does not have fixed formula for starter bacteria; wide regional and individual variations exist in manufacture and preparation.

The traditional method for producing stinky tofu is to prepare a brine made from fermented milk, vegetables, and meat; the brine can also include dried shrimp, amaranth greens, mustard greens, bamboo shoots, and Chinese herbs. The brine fermentation can take as long as several months. Depending on the ways of preparation, the process can be extremely unsanitary; the brine is covered with maggots and has extremely strong rotten odor. Then after the brine is made, fresh firm tofu is marinated in it for a period time ranging from several days to a couple months.

Sometimes quicklime is added to control the fermentation and maggots. Since no starter bacteria were used, the only way to determine whether the tofu has achieved desired quality is by its appearance, e.g. tofu covered in white mold and not black mold.After a successful attempt, the brine can then be kept for future use. This is also the reason why stinky tofu tastes different from vendor to vendor, and the brines are usually considered a trade secret by the makers.[4] Although stinky tofu is very popular in East and Southeast Asia, not many households prepare stinky tofu brine at home due to its strong odor, especially in metro-residential areas.

Even though the traditional method is still widely practiced by street vendors, modern factories often use quicker methods to mass produce stinky tofu. Fresh tofu is marinated in prepared brine for only a day or two, especially for fried or boiled cooking purpose. The process only adds odor to the marinated tofu instead of letting it ferment completely. Some less scrupulous stinky tofu factories in China reportedly used rotten kitchen waste, chemical dye and human feces to prepare the brine in order to achieve the odor and texture in short period of time.

The nature of the stinky tofu production process makes it extremely difficult to pass government food regulation even in Asia. The diversity and lack of formulated methods also makes it nearly impossible for any government to regulate and inspect.In Asia, no stinky tofu factories were ever officially licensed or constantly monitored; in most cases, government inspection can only focus on the cooking procedure and ventilation.

In North America, stinky tofu is often "home-made" in cities with significant numbers of Asian immigrants. For example, some Asian tofu factories in Vancouver, Canada produce stinky tofu underground as a side-business to avoid government inspections.