First, how is sake produced?
In essence, sake is made from water and rice. The process of making sake includes the use of yeast and koji (a type of fungus used in Japan to make alcoholic beverages such as sake and shochu). The koji is mixed with freshly steamed rice before being wrapped in a blanket and incubated. The sweet, dry mixture is then placed in a vat together with more rice and water, and then, fermented with yeast for about two weeks. After that, more koji, steamed rice and water are added to the vat for a second fermentation that lasts about a week. After about four weeks, the sake is filtered, pasteurised and left to mature before the bottling process.
Types of sake
There are six main types of sake: junmai, honjozo, ginjo, daiginjo, junmai ginjo and junmai daiginjo. Junmai, junmai ginjo and junmai daiginjo are all made with 100 per cent rice — the difference between each lies in the rate of rice polishing. Junmai daiginjo is the most premium sake with a lower rice polish rate, which is polished away till 50 per cent or more. Before the sake-making process, each rice kernel is milled (“polished”) to remove the outer layer of the grain and reveal its starchy core. The more the rice has been polished, the higher the classification level, with junmai being the highest classification level.
However, a high classification level doesn’t automatically mean better sake. When it comes to producing top-quality sake, there are other factors that come into play, such as the type and quality of water used and this is often related to the region where the sake is produced. For honjozo, daiginjo and ginjo, they are made with a mix of rice and distilled alcohol, which helps determine the overall flavour of the sake.