Mirin, sushi vinegar, and rice vinegar
Let's start with rice vinegar
Asian rice vinegar is made from rice in which the starch has been broken down by a mould culture. The full, savoury flavour of the vinegar is due to the fact that the grains are constantly in contact with mould, bacteria, and yeasts during the fermentation process. These enrich the vinegar with amino acids, organic acids, and other flavour elements. Asian rice vinegar has a much milder taste than European rice vinegar.
Within Asian rice vinegar, a further distinction can be made between Japanese and Chinese rice vinegar. Japanese rice vinegar has a neutral and mild flavour. Chinese rice vinegar can be black, red, or white in colour and has a stronger flavour than Japanese rice vinegar. The colour difference is caused by the use of different types of rice.
The difference between rice vinegar and sushi vinegar
Besides rice vinegar, there is also sushi vinegar. The difference between the two doesn't need much explanation. Sushi vinegar is simply rice vinegar to which sugar and salt have already been added (and often also flavour enhancers). Sushi vinegar is ready to use straight away when preparing sushi.
Mirin is a type of Japanese alcohol
Mirin is not a vinegar but a type of Japanese alcohol with a sweet flavour. Mirin is made by mixing cooked and ground rice with a distillate of sake. This distillate is called ‘koji’ or ‘shochu’. The alcohol content of sake means it does not ferment any further, and the starch in the rice is converted into glucose. Straining and clarifying the resulting liquid results in mirin. Mirin has an alcohol content of around 14% and contains 10 to 45% sugar.