Why do vegetables turn sour after pickling?

Pickling is a very effective method to preserve vegetables in the early stage. Nowadays, the pickling of vegetables has changed from a simple fresh-keeping method to a processing technology of vegetable products with unique flavor. Kimchi, a traditional food, is the crystallization of China people's wisdom through the ages and a part of the precious cultural wealth of the motherland.

As early as the Northern and Southern Dynasties, Qi Yao Min Shu recorded many different methods of making kimchi, such as processing kimchi with sweet sauce and soy sauce, dregs made of distiller's grains, sweet kimchi made of molasses and so on.

In the Tang Dynasty, kimchi technology not only developed greatly in China, but also spread to Japan. Today, Japan's famous Nara kimchi originated at that time.

After long-term production practice, by the Ming and Qing dynasties, the technology and varieties of pickled vegetables in China had made great progress, and many books were recorded in detail, and some of them have been passed down to this day.

There are more than 600 pickle processing enterprises in China, most of which have a long history and a small scale. Most of the products produced are in bulk, bottled, canned or simple packaging, which has a certain reputation in the local area. In recent years, many modern processing enterprises with a certain scale have been established, such as Unilever Food Company (China), Weihai Dayang Pickle Company and Shanghai Gao Rong Food Co., Ltd.. Due to the novel packaging, a wide variety of products are produced, which are well received by consumers and develop rapidly. At present, most of the well-known pickles enterprises in China operate through the excavation and development of traditional well-known brands and the use of modern technology, equipment and management.