Sulfur Dioxide Excess

Over-addition of SO2 (sulfites) during winemaking. SO2 is a necessary preservative and antioxidant, but excessive amounts at bottling create perceivable off-aromas. Legal limits vary: 160 mg/L for dry reds, 210 mg/L for dry whites, 400 mg/L for sweet wines in the EU.

Burnt match, sulfurous, or acrid character in the nose. At very high levels, a prickling or drying sensation in the throat. Can trigger headaches and allergic reactions in sensitive individuals. Usually dissipates with aeration — aggressive decanting helps.

Precise SO2 measurement and addition, testing free and bound SO2 levels regularly, and allowing wines to rest after SO2 addition before bottling. Using molecular SO2 calculations based on wine pH for optimal protection with minimal addition.