The principle of making kimchi is what is used for fermentation.

The fermentation principle of kimchi is formed by the fermentation of yeast, lactic acid bacteria, acetic acid bacteria, Penicillium and other strains in the fermentation broth. The production of kimchi mainly depends on the fermentation of lactic acid bacteria, which is the earliest method to preserve vegetables in the world.

Lactic acid bacteria is a non-pathogenic bacteria, which does not form toxins or toxic products in its fermentation process and products.

Lactic acid produced by lactic acid bacteria decomposing monosaccharide and disaccharide in Chinese cabbage lowers PH value, and carbon dioxide produced by fermentation makes fermentation container in anaerobic state, thus preventing food from being infected and corrupted by other microorganisms and prolonging the shelf life of food. At the same time, carbon dioxide, acetic acid, ethanol, higher alcohols, aromatic esters, aldehydes, sulfides and so on. Protein produced in the fermentation process gives kimchi a flavor.