The reason why canned herring smells bad is that herring will produce anaerobic bacteria during fermentation, which is also known as the king of bacteria. In the process of herring fermentation, anaerobic bacteria will continue to grow and release propionic acid, hydrogen sulfide, acetic acid and other substances. When these substances are mixed together, they will give off a familiar stench. Every year from April to June, when herring lays eggs, fishermen will salvage hundreds of tons of herring to prepare raw materials for curing herring.
In order to ensure that the herring will not rot and deteriorate during natural fermentation, the producer will put the herring that has just been salvaged into strong brine and then put it into a can for natural fermentation. By mid-August, the herring in the can became sticky and juicy, and the gas in the can also expanded due to the fermentation of the herring, which made the can bulge, which means that the herring has been marinated and its fragrance will be stronger.
Growth environment of herring
Herring is distributed in the Bohai Sea and the Yellow Sea in China, and also in Korea, Japan, the United States, Canada, the western Pacific and the eastern Pacific. Habitat in deep water, suitable for low temperature, will swim to the offshore when breeding. Often swim in groups, which is convenient for breeding offspring, protecting larvae, foraging and resisting enemies. At night, they float to the surface to prey on copepods, pteropods and other planktonic crustaceans.
Each female fish can lay 3-65438+ 10,000 eggs in March-April every year. Herring can live about 20 years.
Many herrings have no teeth or their teeth are fragile. Its swim bladder communicates with the stomach, so it can store excess gas in the stomach. The two protrusions of the swim bladder are connected with the cartilage sacs of the left and right ears to replace the eardrum of the fish. These fish like to live in groups and feed on small plankton. Most herrings swim 3000 kilometers long and return to the season of spawning and fattening, which is also the place where herring spend the winter.
The above contents refer to Baidu Encyclopedia-Herring.