Anna Greenhous: an introduction to sake

Sake is possibly the most misunderstood drink, both in the trade and by consumers. So to try and help remove misconceptions and demystify the world of premium and not-so premium sake here is my introduction to what sake is.

What is sake?

Sake is made from fermented Japonica (short-grained) rice, and is usually between 14-18% alcohol. Sake originally came from Japan, where it's produced in all states. It's also commercially made in other parts of the world, often where there are large Japanese communities, such as the USA, Australia, China, Korea, and Brazil. A large proportion of the lower-end, cheap sake drunk in the U.K is from the U.S where production costs are lower.

There are a multitude of different styles. Premium sake categories such as Ginjo and Daiginjo tend to be more aromatic and delicate, often with fruit, floral and rice flavours. Koshu sake is a fairly unusual style which has been aged, resulting in the kinds of earthy, nutty, flavours found in some Sherries and Madeira. Namazake is unpasteurized, with a distinctively sour tang and freshness to it. Nigorizake is unfiltered, with some rice solids remaining, adding rice flavours and texture, from a light dusting, to an almost gruel-like drink!

There are sake infused with fruit, such as Yuzu, a Japanese citrus, creating a drink similar to Limoncello, but with a more aromatic extra dimension. Amongst others there are sparkling, low alcohol, and cedar-matured sake, along with a multitude of old and new styles developed by maverick sake brewers, including one made from seawater!

People often ask whether sake should be drunk hot or cold. There isn't really a correct answer to this. Just as we drink wine at different temperatures to show it at its best, so you should with sake. Delicate styles such as Daiginjo, Ginjo, Nama and Nigori sake often show best chilled. Fuller flavoured sake such as Koshu, Yamahai and Junmai can also taste good at room temperature or lightly heated. If you serve a sake too warm, it can loose some aroma, similarly if you over-chill a sake the aromas may not be released.

Although it's true that the cheapest, lowest quality sake has traditionally been heated to disguise its poor quality and faults, this is not the only reason. Hot sake in the winter warms you to the bones in the same way mulled wine does in the depths of winter.

Sake doesn't really fall into any other established drink categories in the U.K. It's not distilled, so not a spirit. Often referred to as a 'rice wine' , it's generally considered most similar to wine in style, but the way in which it's made is very different. Unlike grapes, rice doesn't contain sugar. So, just as barley has to be malted to convert starch into sugar to enable fermentation in beer brewing, the starches in the rice also need to be turned into sugars.

A mould called 'koji' is used to break down the starches in the rice to sugar, continuing to break them down during the fermentation process. This technique is unique to sake, enabling it to reach higher alcohol levels without fortification.

What are the main factors which affect the style of sake?

There is a multitude of different styles of sake, but the degree to which the rice grain has been polished down is probably the factor of most interest. The more the grain has been polished down (removing the outer layers which give off-flavours), the finer the sake. Daiginjo and Ginjo are premium sake for which the rice is polished down to the greatest degree. However, there are also good quality sake where the rice is polished down to a lesser degree.

Just as grape varieties impact on the style of a wine, so does the rice variety on sake, though not to the same degree. Some rice varieties are more suitable than others to making sake. Those with large concentrations of starch at the centre of the grain polish down better. Eating rice can be used, but premium sake is usually made from any of the 60+ varieties of sake rice available. Yamadanishiki is the variety generally held in the highest esteem, but that is not to say it guarantees the best sake!

As with beer, the water used to make sake impacts on the final style. Hard water makes dry, crisp styles, and soft water more full flavoured sake. As with beer-brewing in the U.K, famous sake-brewing areas, such as Nada, grew up around good water sources. In the past, local water sources dictated the style of sake. There were also often distinct regional styles, dictated by local raw materials and climates. However, with advances in transportation and science, these local differences have become less important. Breweries today can use whatever raw materials they want, use new technology to control temperatures at fermentation, and create different types of water, enabling them to make any style of sake they wish.

Alcohol may or may not be added depending on the categorisation of the sake. Alcohol is not generally added to increase the final alcohol level. A small addition of alcohol can pull out flavours and aromas in premium Daiginjo and Ginjo sake. Addition of alcohol in larger quantities can also be used in a very different way, to increase yields inexpensively when producing cheap, low quality sake. Junmai sake, often referred to as 'pure rice sake' is made with no addition of alcohol. There is an ongoing debate within the sake world as to whether Junmai is superior to or more authentic than non-Junmai Daiginjo and Ginjo which are fairly recently developed styles.

In Japan, arguably the most important factor affecting the style of sake is the Toji, the head brewer who decides what sake making methods will be used. Different yeasts, temperatures and speeds of fermentation, filtration methods and lengths of maturation result in different styles. The Toji will also decide which water and rice will be used, whether alcohol is added, and the degree of polishing. When a new Toji joins a brewery, the sake style of that brewery is likely to change - yet another factor that can affect a sake's taste.

With so many different things to consider, it's no wonder that many consumers find sake inaccessible. But the beauty is that with so many different styles, there really is something for everyone! In this column, I will try to guide you through the world of sake and the culture around it - how it's made, how to drink and serve it, where to find it in the U.K - and keep you up to date with the main trends in the market.

For more on sake follow Anna on Twitter: @tastewinesake

• Richard Siddle
• Sommeliers