Cork-wine interaction studies: liquid absorption and non-volatile compound migration

Abstract

Aims: To provide a better knowledge of cork-wine interaction, focussing on absorption of liquid by the cork stopper and overall migration of non-volatile compounds from the cork-stopper to liquid.

Methods and results: Natural cork stoppers and 1+1 technical cork stoppers (agglomerate cork body ended with natural cork washers), with and without surface treatment, were used to close bottles filled with 12 % v/v ethanolic solution and removed after 3, 6, 12 and 24 months of contact. Mean and limit values of absorption and overall migration at each time are used to compare treated and non-treated stoppers. Variation of absorption with contact time was studied by adjusting the ABSORPTION = a · √t model (R²: 0.8572 - 0.9756).

Conclusion: Most of the overall migration is due to natural components of cork. Contact time and type of cork stopper are the factors responsible for the greatest variability. Surface treatment increases overall migration (2 mg/stopper) and reduces liquid absorption (more than 10 %).

Significance and impact of the study: The results show how a correct characterization of stopper and surface treatment is needed to predict the evolution of cork-wine interaction.