Miso

Miso is a traditional Japanese seasoning produced by fermenting soybeans with salt and kōji (a type of fungus, typically Aspergillus oryzae). Other ingredients such as rice, barley, or seaweed may also be included. The fermentation process can take from a few weeks to several years, developing a complex, savoury flavour.

Miso is primarily used to add a deep, umami flavour to foods. It is a key ingredient in miso soup and is also used in marinades, dressings, sauces, and glazes. Manufacturers use it to enhance the savoury taste profile of a wide range of products, particularly in Asian-inspired dishes.

Miso is not considered a food additive in the UK and therefore does not have an E-number or require authorisation on the Register of Food Additive Authorisations. It is a fermented food, and some research suggests potential benefits associated with the consumption of fermented foods, though evidence is mixed and more peer-reviewed studies are needed. The World Health Organization's International Agency for Research on Cancer (IARC) has classified the consumption of salt-preserved vegetables, a category that includes some traditional miso production methods, as Group 1 carcinogenic to humans. However, modern miso production methods and typical consumption levels mean this classification is not directly applicable. EFSA has evaluated the safety of fermented foods in general terms, noting their long history of safe consumption.