This 20 year aged mirin is the pride of producers, Kankyo Shuzou. This dark, rich flavoured mirin was created by accident when flasks were mislaid in a cellar and re-discovered 10 years later. Carbohydrates and amino acids from the rice in the mirin oxidised and took on a black colour, upon tasting pleasant notes of black sugar, rum and raisin combined in a full but smooth flavour and a new product was born. Mirin manufacturers usually add sugar during the rice and koji fermentation process with additional cane sugar alcohol to speed up the maturation. Here, nothing is added, the production process is slower and the resulting flavours are natural and pure.