Microbiological stability of dealcoholised wines using SO₂ and sorbic acid

Introduction: Dealcoholised wines are rapidly gaining popularity. The removal of ethanol and the substantial residual sugar content (about 35–50 g/L) make these products vulnerable to microbiological threats. Therefore, the questions related to dealcoholized wines stability have become relevant for producers, in particular, if dimethyl dicarbonate (DMDC) is not added these wines.

Methods: A dealcoholised Riesling wine was used for the experiments, which involved the wine being bottled with various doses of SO₂ and the addition of potassium sorbate; and bottle opening for wine consumption and their subsequent storage. The following analyses were performed: FTIR analysis, CO₂ pressure measurement inside the bottles, membrane filtration, and sensory analysis.

Results: About 1 mg/L of molecular SO₂ demonstrated a good level of antimicrobial activity when the dealcoholised Riesling wine was sterile bottled. After bottle opening and simulated consumption, the same wine remained microbiologically stable in the bottle for at least one week.

Conclusions: This study is among the first to determine which molecular SO₂ levels can provide adequate protection to dealcoholised wines and the effect of sorbic acid.