Sulfur dioxide (SO2) has been widely used in winemaking since its introduction in ancient Egypt.
Neither the acidity of the wine nor the SO2 alone are sufficient to provide antimicrobial protection, since SO2 is only effective in an acidic environment. However, since grapes have a natural acidity from tartaric acid and malic acid, they keep wine in an acidic condition and sulfur dioxide has been a boon to the wine industry for hundreds of years.
In Japan, only beer, wine and fruit wines are permitted to use SO2 in production. SO2 was tested as an antimicrobial agent in sake production but due to reduction of flavor, its use was disallowed, except for in sake-kasu . Therefore, in sake production, lactic acid is widely used for antimicrobial protection.
This article is written based on the archive of The National Tax Agency on November 1st 2016.