Sake just means alcohol in Japan, whereas the rice-based drink that we know as sake is in fact called ‘nihonshu’, Japanese alcohol made from rice. It has been made in Japan for over 1000 years but and in the form of premium sake such as ginjo, only around 50 years.
There are, for example, around 70 rice varieties used for sake production, with three main varieties, yamadanishiki, gyohakumangoku and miyamanishiki making up nearly three-quarters of the total sake rice cropping area of around 15,000 hectares.
Sake generally weighs in at around 15 – 16% ABV, although, of course, there are exceptions to every rule. It has just a fifth of the acidity of wine. What it lacks in wine’s crisp, refreshing acid bite however, it more than makes up for in texture, subtlety of flavour and diversity of style.
Sake’s quality grades are determined by the polishing ratio. i.e. how much of the rice grain is milled away before the starchy core is ready to be converted by the koji mould to fermentable sugar. Grades and accompanying prices are a guide to quality but, as with wine, it can often pay to find a lower grade, premium example from a top brewery.
Perhaps the most significant contribution to the style and flavour comes from the aims and techniques of the ‘toji’, the master brewer. At the brewery, the rice is washed, steamed and cooled before before roughly a fifth of the rice is spread out on wooden tables where the starch is broken down into fermentable sugar by the addition of koji mould spores.