Sake 101

Nihon-shu (日本酒) or sake as we know it, is a fermented alcoholic beverage traditional to Japan. It is made from rice, the staple food of the Japanese, and thus is deeply rooted in people’s lives. The process of sake making is more complex than wine or beer. With wine production there is a focus on extracting the natural flavour of the raw material - grapes - and the expression of the vineyard. With sake however the main ingredients - rice and water - are virtually tasteless and odourless by comparison. With the utilisation of yeast and kōji-kin (the starch-breaking mould aspergillus oryzae) along with the skill and craftmanship of the tōji (master brewer), these raw materials are brought to life to create flavour, fruit-like fragrance, umami (savouriness), richness, and a delicate sweetness that is silky-smooth. Wine depends on the vineyard whereas sake depends on the skill. Sake also relies more heavily on yeast than winemaking, creating a wide range of flavours with aromas, acids, sugars etc. The brewing of sake is complex compared to other alcoholic beverages and an overview of the process is as follows:

POLISHING 

The first step is polishing the brown rice into white rice. Sake is made with white rice (with some exceptions) so brown rice is
polished/milled to remove the outer grain which reveals the white rice. The percentage that the rice is milled along with the type of rice used is one of the factors of the style, aroma and flavour of the finished sake.

WASHING/SOAKING/STEAMING 

The rice is then washed, soaked and steamed to cook the rice through to the center.

KŌJI

The next step is to create the kōji, where approximately 25% of the rice needed for a single batch of sake is taken to the kōji-muro (kōji room) and the kōji-kin (starch-breaking mould) is applied.

STARTER

Next is the creation of the moto or shubō (starter). Around 7% of the steamed total rice volume, including kōji are used to cultivate yeast. This is done in one of three methods: kimoto, yamahai or sokujō.

MOROMI: Once the Moto is ready, steamed rice, kōji and water are added to create the moromi (main fermentation mash) which then undergoes fermentation.

PRESSING: After the Moromi is fermented, the mixture is pressed and separated into clear sake and sake-kasu (sake-lees).

FINALLY: There are a number of post-fermentation processes which vary depending on the maker at this point before the sake is then bottled.

STYLES OF SAKE

Kimoto 生酛 - Also known as the ‘first’ starter method, kimoto is the traditional method of grinding the rice, water and koji together with wooden paddles. The mashing action encourages lactic bacteria to become involved in the starter, essentially ‘feeding’ the yeast. This a very labour intensive way of creating the starter.

Yamahai 山廃 - This is the second traditional starter technique, where a small amount of the ingredients are brought together and instead of ‘mashing’ as with Kimoto, the ingredients are just left alone. This again allows lactic bacteria to become involved in the starter by feeding the yeast.(Both the Kimoto and Yamahai starter method take approximately 4 weeks to create.)

Sokujō 速醸 - This is known as the modern starter method. A small amount of lactic acid is added to the starter, this ‘feeds’ the yeast straight away. Today this is the most common way of starting the Moto and takes approximately 2 weeks to create the starter.

GRADES OF SAKE

Junmai (純米)
This is sake loaded with character. Purely made from rice, water & kōji and rich in flavour elements. Junmai has more acidity, more body and more amino acids than other sake types, hence its gratifying richness of flavour. Whilst some examples do have a certain floral element, brewers aim for earthier and ricier components. The aromas and flavours of the rice itself a more prevalent in this type of sake.

Honjōzō (本醸造)
Honjōzō is sake to which a small amount of distilled ethyl alcohol [brewers alcohol] has been added to the fermenting sake at the final stages of production. [Water is added later, so that the overall alcohol content does not change.] Honjōzō, like Junmai, is made with rice that has been polished [milled] so that at a minimum of 70% of the rice grain remains. This, plus the addition of distilled alcohol, makes the sake lighter, a touch drier, and potentially, easier to drink. It also makes the fragrance of the sake more prominent. Honjōzō often makes a good candidate for warm sake.

Ginjō (吟醸) & Junmai Ginjō (純米吟醸)
This is sake made with rice that has been polished [milled] so that no more than 60% of its original size remains. In other words, at least the outer 40% has been ground away. But that is only the beginning: Ginjō is made in a very labor intensive way, fermented at colder temperatures for a longer period of time. The flavour is complex and delicate, and both the flavour and the fragrance are often [but not always] fruity and flowery.