Project Number
P04000008
Project title
Effect of yeast contact time on the flavour profile and quality of Méthode Cap Classique wines
Project leader
Jolly, N P
Team members
Jolly, N P
Booyse, M
Ohlson, S
Van Breda, V
Adonis, P
Ferreira, P
EXECUTIVE SUMMARY
Objectives & Rationale
Current legislation for South African bottle fermented sparkling wine or Méthode Cap Classique (MCC) prescribes a minimum of nine months on the yeast lees before disgorgement. Industry wishes to increase the lees contact time to a minimum of 12 months for a standard category, and 24 months for a higher category. However, limited scientific data is available to support the proposed classifications. The objective of this project was therefore to collaborate with the Cap Classique Producers Association (CCPA) and specific MCC producers in microbial, chemical and sensory monitoring and analyses of Chardonnay and Pinot noir MCC wines to confirm anecdotal evidence and give scientific support to the proposed changes in legislation. The project was planned to run over three financial years to cover two separate 24-month production processes. An extension of the project was granted to facilitate a longer than 24-month maturation time, in line with industry practices, and for a final year of data analyses.
Methods
Eight MCC producers donated fourteen 2012 and ten 2013 MCC wines with lees intact. The wines were stored at Le Lude Cellar, Franschhoek for the duration of the project. The wines were production wines and not specifically produced for the project. The wines were regularly withdrawn for microbial, chemical and sensory analyses and the results were reported according to months on lees. Chemical analyses included standard chemical parameters (WineScanTM), spectral fingerprinting, total extract; nitrogen (yeast assimilable nitrogen; Lecco combustible nitrogen, amino acids), total polysaccharides, volatile aroma compounds, and polyphenols. Sensory analyses by an industry and research team tasting panel was done on disgorged wines.
Key Results
Total amino acid profiles could be used as a tool to distinguish young from mature wines while yeast assimilable nitrogen (YAN) analyses may have value as a tool for monitoring individual wines for autolyses development. Infra-red fingerprinting and pattern recognition methods could also be a useful tool to categorise wines based on the time on yeast lees. Sensory analyses showed that MCC wines develop further after nine months on the lees. This development is not linear and a favourable time for disgorgement would be vintage dependant but could be after 12-13 months, 25-30 months and after 50 months on the lees.
Conclusion and Discussion / Recommendation
The data generated during this investigation supports the concept of a multi-tier classification of MCC wines. This will bring about an overall improvement in the quality of the wines, and promote a better understanding by the consumer. Favourable times to disgorge would be after 12-13 months, 25-30 months and after 50 months on the lees. However, due to vintages differences, a controlled sensory evaluation would have to be carried out to determine if the MCC wines are stylistically correct. This could entail something similar as is done for Noble Late Harvest vs. Natural Sweet wines by the Wine and Spirit Board sensory panels.
Presentation(s)
Jolly, N P. 2012. Effect of yeast contact time on the flavour profile and quality of Methode Cap Classique wines. Presentation at the 3rd Technical Day of the Cap Classique Association. 26 July, Stellenbosch, South Africa.
Jolly, N P. 2014. Effect of lees contact time on Methode Cap Classique wines: Preliminary observations. Presentation at the 5th Technical Day of the Cap Classique Association. 18 July, Stellenbosch, South Africa.
Jolly, N P, van Breda, V, Booyse, M, Hutchinson, U, Jooste, A. 2013. Effect of yeast contact time on the flavour profile and quality of Méthode Cap Classique wines. Paper presented at the 35th Conference of the South African Society for Enology and Viticulture. 13-15 November, Somerset West, South Africa.
Jolly, N, van Breda, V, Booyse, M, Hutchinson, U, du Plessis, Z, Fass, B, Jooste, A. 2014. Effect of lees contact time on Méthode Cap Classique wines. Paper presented at the Winetech – Winemaking Techniques and Practices Programme Workshop. 2 October, Stellenbosch, South Africa.
Jolly, N, van Breda, V, Booyse, M, Minnaar, P, Harold, G. 2016. Effect of lees contact time on the chemical and flavour profile of Méthode Cap Classique wines. Paper presented at the 6th Cap Classique Technical Seminar. 22 July, Stellenbosch, South Africa.