Like potassium sorbate, sodium benzoate is a yeast inhibitor. Rather than killing off the yeast, it hinders yeast’s ability to multiply and be active. Winemakers usually add small quantities of sodium benzoate to sweet and sparkling wines when active fermentation has ceased. For sweet wines, it can also be added at the same time as the final syrup.
Sodium benzoate can also be added to wines that have difficulty maintaining clarity after fining. It can also be used post-fermentation balance the wine’s pH and pressure.
When using sodium benzoate as a stabilizer, it must be used in conjunction with an aseptic dose of potassium metabisulfite ( Campden tablet).