Why is stinky tofu black? The harm of stinky tofu

Street food is a kind of food that is very enjoyable and down-to-earth. There is one food that attracts people to stop and taste, that is stinky tofu. Speaking of stinky tofu, do you know why stinky tofu is black? Do you know what makes stinky tofu black?

Contents of this article

1. Why is stinky tofu black?

2. What is the black color of stinky tofu made of?

3. Harms of stinky tofu

Why is stinky tofu black?

Because the marinade for stinky tofu contains black fermented black beans, the tofu will turn black when soaked, which is considered a healthy black color.

In order to make the stinky tofu authentic black, some businesses add a chemical raw material called green vitriol (ferrous sulfate) to make the color of the stinky tofu more realistic.

What is the black color of stinky tofu made of?

1. Preparation of brine: Bring cold water and fermented black beans to a boil and cook for about 30 minutes. Then filter out the fermented black bean juice, cool it down, add 100 grams of soda ash, 200 grams of shiitake mushrooms, 4000 grams of winter bamboo shoots, 750 grams of salt, 3 taels of Maotai liquor, and 3 kilograms of tofu brain. Soak for about 15 days (stir once a day), and it will become brine after fermentation.

The standard for testing the normality of brine is fermentation. If it does not ferment and the smell is abnormal, the method is to burn the clean fire bricks red and put them in the brine to promote fermentation. At the same time, add some seasoning according to the above formula to make it ferment and taste normal.

2. Tofu fermentation: Add 3 grams of alum into a pot, add boiling water and stir with a stick, put in tofu, soak for 2-5 hours in spring and autumn, 1-2 hours in summer, 6-10 hours in winter. Soak more for hard tofu and less for soft tofu. Take out after braising, wash with cold boiled water, put into a sieve to drain the water (keep the water after washing), and pour into the brine when the water is concentrated.

The harm of stinky tofu

my country's Food Hygiene Law strictly prohibits the use of chemical raw material ferrous sulfate as a food additive. "The iron sulfide generated by the reaction of ferrous sulfate and fermented products is black, so the stinky dried tofu turns black when soaked in green vitriol. Fermented stinky dried tofu contains a lot of fermentation bacteria, enzymes and other substances. Ferrous sulfate will react quickly when it comes into contact with these fermented products. In addition to generating iron sulfide and other sulfides, it will also generate many compounds that are harmful to the human body. Long-term consumption of this stinky tofu will cause symptoms such as general weakness, headache, loss of appetite, and blurred vision." The staff member said that according to the local standards for soy products, the stinky brine used to make stinky tofu should be bluish-black, not ink-black, and contain the fragrance of spices. Consumers are advised not to buy fried stinky tofu that is too dark and smells too bad from unlicensed stalls on the roadside.