Is it normal for tofu to have a slight sour taste

A slight sour taste in tofu may be a normal fermentation phenomenon, but excessive sourness or accompanying odor may cause spoilage. Tofu undergoes fermentation during the production process, and some of the sour taste comes from the metabolic products of beneficial bacteria such as lactic acid bacteria. This sour taste is usually gentle and odorless. If tofu is stored for too long or the ambient temperature is too high, it may become spoiled and rancid due to excessive bacterial growth, resulting in a pungent sour taste and a sticky texture. Traditional brine tofu or gypsum tofu may have a slight acidity due to differences in craftsmanship, especially bulk tofu is more prone to natural sourness in summer. The sour taste of fresh tofu is often mixed with the bean flavor, and the acidity is evenly distributed throughout the entire tofu, without local stickiness or darkening of color. After purchase, it is recommended to soak in clean water and store in refrigeration. The acidity will gradually increase within 2-3 days. If the sour taste of tofu is accompanied by moldy spots, sticky streaks, or a pungent putrid odor, it belongs to the phenomenon of spoilage. Some vendors may use inferior raw materials or illegal additives to cause abnormal sour taste, which may cause gastrointestinal discomfort after consuming such tofu. When the packaged tofu shows swelling and strong acidity, it indicates contamination by miscellaneous bacteria and should be discarded immediately.

When making daily purchases, gently press the surface of tofu to test its elasticity. Fresh tofu feels tight and has a smooth cross-section. It is recommended to prioritize using boxed tofu stored in cold chain and consume it as soon as possible after opening. For people with weak digestive function, tofu can be blanched to remove some acidity before cooking. If you accidentally consume spoiled tofu and experience abdominal pain and diarrhea, seek medical attention promptly.