The rarity of sulfur dioxide

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.