Ageing of sweet wines: oxygen evolution according to bung and barrel type
Abstract
Barrel ageing is a crucial step in the wine process because it allows many changes to the wine as enrichment, colour stabilization, clarification and also a slow oxygenation. Effects of the oak barrel have to be known to prevent oxidation of the wine. The type of bung used during ageing is also a parameter to consider. Ageing sweet wines in barrel is a real challenge. These wines may need some oxygen at the beginning of ageing but they should be protected at the end of their maturation, to avoid oxidation. How to regulate oxygen intakes? How to measure it without opening the barrel? We have tried to answer these questions with an innovative assay. The trial was conducted with 4 modalities taking into account 2 bung types (a glass bung and a special bung made with elastomer) and 2 barrel types (a reference and a new barrel for white wines especially, called PFB). After filling the barrels with the same wine batch, oxygen is monitored all along the ageing with a specific sensor without opening the bung. 4 sensors per barrel are set. The oxygen measurements obtained in sweet wines aged in two barrel and bung types have been reported for the first time without opening the barrel, thanks to these specific sensors. Association of elastomeric bung and PFB barrel leads to lower oxygen intakes. The bung type is of major importance. Glass bungs allow oxygen entrance around 6 mg/L near the bung, whereas elastomeric bungs reduce this concentration to 1 to 3 mg/L only. Moreover the barrel type seems to enhance this impact because PFB barrels (made especially for white wines protection against oxidation) show higher decreases than reference barrels.
Issue: Macrowine 2016
Type: Poster
Authors
*Chêne & Cie