A traditional condiment in East and southeast Asian cuisines, soy sauce originated in China. It is made from a fermented paste of boiled soybeans, roasted grain and brine. Soy sauce has a distinct basic taste called umami, which means “pleasant savoury taste”. Chinese soy sauces are primarily made from soyboeans with small amounts of other grains and can be split into two classes. Light or fresh soy sauce is a thin, opaque, lighter brown sauce brewed by culturing steamed wheat and soybeans with aspergillus (a type of fungus). The mixture is then fermented in brine. It is the main soy sauce used for seasoning and is saltier, but has less colour, than dark soy sauce. It also has a distinct flavour. Dark, or old, soy sauce is, as the name implies, darker and slightly thicker than light soy sauce and is brewed for longer. It may contain added caramel colour and/or molasses to give it its distinctive appearance. This variety is used mainly in cooking and has a richer, slightly sweeter, less salty flavour than the light version.
In Japan, there are five common types of soy sauce each with their own subtle difference in ingredients and method of production.
- Koikuchi, roughly translated, means “thick flavour”. Koikuchi accounts for the majority of soy sauce produced. This is the “standard or plain” type you find in most Japanese restaurants.
- Usukuchi is considered the “weak taste” variety. It is saltier than plain soy sauce (koikuchi) and lighter in colour.
- Tamari is darker and richer in flavour than Koikuchi and is commonly used for sashimi. This is wheat free and can be used by people with gluten intolerance. It is considered the “original” Japanese soy sauce as its recipe is closest to the soy sauce introduced to Japan by Buddhist monks from China in the 7th century.
- Shiro: literally means white. In direct contrast to Tamari, Shiro shoyu uses mostly wheat in its production and very little soybean giving it a light appearance and sweet taste.
- Saishikomi: twiced brewed. This variety of soy sauce is darker and more strongly flavoured.
In Indonesia soy sauce is known as kecap. There are three common varieties: Kecap asin is similar to Chinese light soy sauce but is thicker and stronger. Kecap manis is a sweet soy sauce made with palm sugar. It is thick and almost syrupy and partners well with meat, poultry and seafood dishes. Kecap manis sedang is a medium sweet soy sauce, which has a less thick consistency, is less sweet and is saltier than kecap manis.