Almost all sake on the market has been pasteurized twice - once just after brewing, and once again before shipping. This is done by either running the sake through a pipe submerged in hot water, or by submerging the sake after it has already been bottled. Pasteurization permanently deactivates left over enzymes which can become active again if the sake is stored in slightly higher temperatures - a process that could possibly ruin the flavor.
However, namazake is sake that has not been pasteurized. It must be refrigerated since it is less stable than other varieties, and will develop rather unusual flavors if not stored properly. When namazake spoils it is known as hi-ochi - a condition that can usually be spotted rather easily because a thick, white liquid will condense and float unattractively in the bottle.
When stored properly, namazake is smooth, easy-drinking and highly enjoyable. While the aromas are rather subtle, it has a rich, textured palate as well as a fresh, lively and elegant flavor. All classifications of sake can be pasteurized (or not), and it doesn't have any effect on the overall quality of the sake.
|Ohyama Tokubetsu Junmai Nigori|
Nigori is sake that has not been filtered, and some of the fermented rice has deliberately been left in the bottle. This produces a white, cloudy and somewhat opaque sake (not to be confused with spoiled namazake!) that offers a full body, a smooth, creamy texture, and mildly sweet flavors. Although it lacks the subtlety and refinement of a premium sake, nigori is an excellent accompaniment to a variety of light dishes, especially seafood.
If you expect your sake to be fruity, floral and delicate, do not order anything with "yamahai" on the label. While these sakes can be bold, complex and delicious, they can definitely catch you by surprise with their gamey, earthy notes of mushroom, mineral and herbs. This is caused by a slow acting yeast starter that allows for more bacteria and wild yeasts to be incorporated into the brew. These sakes pair well with heartier entrees such as grilled meat or rich pasta dishes.
|Dewatsuru Kimoto Junmai|
Put simply, kimoto is the traditional method of creating the yeast starter - until 1920 all sake was made by mixing rice, koji and water into a puree in order to help the yeast cells reproduce faster. The brewers had to stand around a small tub of this mixture and constantly stir in a rhythmic motion which helped to speed up the production of lactic acid in the moto. The lactic acid protects the moto from unwanted bacteria that may cause unusual flavors, or even spoil the sake. While this tiring, tedious method is no longer common, a few breweries still produce sake this way. The flavor profile is quite similar to sake produced with the yamahai method, offering rich, pronounced notes of earth and mineral.
Of course since we're talking about sake, the brewing variations are endless, but these are the most common terms you will come across. We hope our Sake 101 series has given you further insight into this traditional beverage, and helps you to understand the sake you are tasting or buying.
Cheers from DrinkUpNY!