From an enological point of view, SO2 can produce organoleptic
alterations in the final product, neutralize the aroma and even pro-
duce characteristic aroma defects (Ribereau-Gayon, Dubourdieu,
Doneche, & Lonvaud, 2006). Additionally, only molecular SO2 (a
fraction of the free sulfite present) possesses antioxidant and
antimicrobial properties and its percentage depends on the wine
pH. High pH decreases its proportion, and therefore its
effectiveness.