Project number:
P04000204
Project leader
Dr Neil Jolly
Institution
ARC Infruitech Nietvoorbij, Stellenbosch
Start date
2018
Objectives and Rationale
Cap Classique wine producers are continually striving to increase quality and produce niche products. A production tool could be the use of a cork instead of a crown cap during the second fermentation. Anecdotal evidence shows that this leads to stylistic improvements to the wine. The aim of this project is therefore a comparison of Method Cap Classique wines fermenting and ageing under cork and crown caps.
Methods
The same wine bottled under a cork and crown cap was donated by three different cellars from available commercial and experimental wine stocks. The wines underwent physical, chemical and sensory analyses. Analyses included phenolic acids that can serve as marker compounds to monitor the ‘cork effect’, and the study of bubble kinetics.
Key Results
Much variation is seen across the different batches of wines, but generally there are distinct differences between cork and crown capped wines. This can be observed in the wine’s infra-red fingerprint and as changes in the phenolic profile. Effects are also evident in sensory and CO2 attributes. Cork wines are more complex, but tend to have lower pressures, albeit still well within legal requirements.
Key Conclusion of Discussion
Every bottle of Cap Classique wine within a batch is a separate fermentation, so some degree of variance can be expected. Despite this a ‘cork effect’ can be seen in the generated data. Cork can therefore be used during the second fermentation and maturation on the yeast lees to enhance the sensory profile of Cap Classique wines.
Take Home message for Industry
A cork closure can be used during the second fermentation and maturation on the yeast lees to enhance the sensory profile of Cap Classique wines. However, certified TCA taint free corks should be used.