Traditionally sake was brewed only in the winter.
While it can now be brewed year-round, there is still seasonality associated with sake, particularly artisanal ones.
The most visible symbol of this is the sugitama (杉玉), a globe of cedar leaves traditionally hung outside a brewery when the new sake is brewed.
The leaves start green, but turn brown over time, reflecting the maturation of the sake.
These are now hung outside many restaurants serving sake.
The new year's sake is called shinshu 新酒 ("new sake"), and when initially released in late winter or early spring, many brewers have a celebration, known as kurabiraki 蔵開き (warehouse opening).
Traditionally sake was best transported in the cool spring, to avoid spoilage in the summer heat, with a secondary transport in autumn, once the weather had cooled, known as hiyaoroshi 冷卸し ("cold wholesale distribution")—this autumn sake has matured over the summer.

There is not traditionally a notion of vintage of sake—it is generally drunk within the year, and if aged, it does not vary significantly from year to year.
Today, with influence from wine vintages, some breweries label sake intended for aging with a vintage, but this is otherwise rare.
Traditionally sake was brewed only in the winter. While it can now be brewed year-round, there is still seasonality associated with sake, particularly artisanal ones. The most visible symbol of this is the sugitama (杉玉), a globe of cedar leaves traditionally hung outside a brewery when the new sake is brewed. The leaves start green, but turn brown over time, reflecting the maturation of the sake. These are now hung outside many restaurants serving sake. The new year's sake is called shinshu 新酒 ("new sake"), and when initially released in late winter or early spring, many brewers have a celebration, known as kurabiraki 蔵開き (warehouse opening). Traditionally sake was best transported in the cool spring, to avoid spoilage in the summer heat, with a secondary transport in autumn, once the weather had cooled, known as hiyaoroshi 冷卸し ("cold wholesale distribution")—this autumn sake has matured over the summer.
There is not traditionally a notion of vintage of sake—it is generally drunk within the year, and if aged, it does not vary significantly from year to year. Today, with influence from wine vintages, some breweries label sake intended for aging with a vintage, but this is otherwise rare.
Sake