From the point of view of food classification, stinky tofu belongs to the family of bean curd milk, the common soy sauce tofu (red square, red curd) is its brother, the production method of these bean curd milk varies according to the local climate, customs, and people's taste preferences. Generally speaking, the production method of tofu milk is divided into two categories: microbial culture type and marinated type, in which the microbial culture of tofu milk can be divided into fungal tofu milk and bacterial tofu milk. The production process of stinky tofu is therefore divided into two types: marinated process and microbial fermentation process. Stinky tofu made by marinating process is represented by Changsha Stinky Tofu. To make this type of stinky tofu, the first step is to soak the tofu blanks in dissolved alum, the main component of which is ferrous sulfate, which serves as a coloring agent and produces the special smell of stinky tofu. After soaking for a period of time, people will be configured to pour the stinky brine, brine soaked for a period of time, when these tofu billet shaped flavor, then the tofu billet fished out, drained, deep-fried, and then brushed with a layer of seasoning can be eaten. In the past, people also have a way to soak the tofu blanks with the salty and stinky water of pickled shirihong, but this production method takes about 15~30 days, and for the businessmen who continue to sell stinky tofu, time is money, and is seldom used nowadays. The microbial fermentation type stinky tofu production process is much more troublesome, and this kind of stinky tofu is prepared from soybeans. First of all, people screen soybeans, soak, rinse, grind, remove residue, make soybean milk, and then made of tofu brain, and then pressed into shape, cut blocks, to this point, different businesses will be inoculated with their own unique bacteria or fungi on the block of tofu, and then allowed to grow, when the block of tofu by these microorganisms "moisturizing" almost, has grown hairy when the block of tofu, the microbial fermentation of stinky tofu, the microbial fermentation of stinky tofu is a lot of trouble. When the tofu block is "moisturized" by these microorganisms, it has been full of hair, the merchants will rub off these hairs, further marinate, and then pour their own brine after a period of time can be mounted altar, mounted altar stinky tofu is generally not sold immediately, but let it continue to ferment for a period of time, and ultimately get the finished product stinky tofu. Stinky tofu made by this process is softer and tastier, but it also takes more time and experience.

While different people have mixed feelings about stinky tofu, it is undeniable that it is a very nutritious food. First of all, the nutritional value of soybeans is needless to say, rich in protein and trace elements, which is good for the body; secondly, stinky tofu is a reprocessing of soybeans, and some of the proteins within the fermented soybeans will be broken down by the microorganisms into smaller amino acids, which is good for human absorption; thirdly, the microorganisms will also produce some vitamins and other substances when they are growing, which are necessary to maintain the normal physiological metabolism of the human body. But even so, we have to consider the risk of consumption of stinky tofu. For the pickling process of stinky tofu, in the pickling time will use alum, and some unscrupulous merchants in order to save money will often use industrial alum instead of food alum, these industrial alum in the production of a lot of heavy metals will be mixed, after eating will lead to abdominal pain, nausea, vomiting, and even pulmonary fluid, shock and other symptoms of poisoning. Some even use sodium sulfide, which is not allowed to be added by the state, to replace alum for dyeing and flavoring, which seriously threatens the health of consumers. Although fermented stinky tofu does not use alum, but when inoculated with microbial fermentation, if the disinfection measures and sealing measures are not done well, it is easy to introduce toxic bacteria, such as Escherichia coli, Staphylococcus aureus and so on. They will likewise cause diseases when consumed by human beings. Even if the production is not a problem, sales may be a hidden danger, many fried stinky tofu like to open in front of schools, neighborhoods, close to the road, on the one hand, the air will be contaminated with dirt to the food, on the other hand, a long time not to change the oil may be oxidized after the change into carcinogenic substances. Anyway, remember that disease enters by the mouth, don't let the delicious and nutritious stinky tofu really become stinky things.