Sparkling sake (Happo-sei Seishu)

Sparkling sake (happo-sei seishu, 発泡性清酒), also called "sparkling nihonshu," is a type of Japanese sake that has gained popularity in recent years. It acquires its effervescence through a secondary fermentation in the bottle, which produces carbon dioxide. Under Japan's Liquor Tax Act, it is classed as a brewed alcoholic beverage, and its product category is sake (seishu). Some sparkling sake has a high alcohol content and requires care when the bottle is opened, while others have a low alcohol content and are finished lightly cloudy (usunigori) and sweet. There are also versions made by adding carbon dioxide gas to give the sake its fizz, so a variety of styles exist. However, newly pressed namazake (unpasteurized sake) that becomes slightly sparkling naturally during production is not included in this category. This newer style of sake resembles Champagne in both its mouthfeel and appearance. It can be enjoyed on special occasions as well as at casual gatherings, and it is well loved by many people.