Growing Conditions and Wine Quality of Vitis vinifera L. Pinot noir

1. Growing Conditions and Wine Quality of Vitis vinifera L. Pinot noir Gerard A. Logan, G. Stanley Howell and Muraleedharan G. Nair. Michigan State University, East Lansing, Michigan, United States of America. INTRODUCTION Wine is constantly changing through a myriad of complex chemical reactions, not the least of which, are those reactions leading to the final perceived colour of the wine. The colour stability of Vitis vinifera L. Pinot noir is a very complex subject, especially in cool climate growing regions, and is compounded further by clonal differences and winemaking procedures. There is an increased need in the industry for a clearer understanding of the manner in which clones and conditions of culture, including macro-, meso- and microclimate affect the final colour of Pinot noir. The primary aim of this project was to investigate the effects that clone and standardised commercial vineyard and winemaking techniques have on the final colour Pinot noir. • RESULTS AND CONCLUSIONS • Summarised data is shown to the left. • Anthocyanin content differs dramatically throughout the growing season. Clone 113 displayed least stability in both years at this location. • The final colour of Pinot noir wines, does not benefit statistically from very high anthocyanin content in fruit when extraction techniques are standardised. • Visually, the wines show a marked increase in colour intensity compared with other Pinot noir from the same location. • Statistically, there is no correlation between anthocyanin content of wine and clone. • Anthocyanin content in fruit is affected by clone and season, in different magnitudes. • Further analysis via HPLC is required to separate samples on the basis of anthocyanin concentration. Year One Year Two MATERIALS & METHODS Plant Material: V. vinifera L. Pinot noir, clones UCD13, 113 and 115, all located on the Michigan State University’s Southwest Michigan Research and Extension Center, located in Benton Harbor, Michigan, USA. Vines were all treated uniformly, in a commercial vineyard manner except they were thinned to 30 clusters per vine at veraison. Sampling began at veraison, and consisted of two whole clusters from each clone, this would be repeated twice more at regular intervals until harvest. Fruit was harvested by hand. Sample Preparation: Wine was produced using the crop harvested after cluster samples had been taken, and stored at 5.0°C for analysis. Each sample cluster had the stems and seeds removed, and the remaining pulp was puréed and poured onto trays. The trays were frozen to -20.0°C and stored as such. The samples were then freeze dried for shipping and further storage. Dried material was then re-hydrated by weight with wine-pH water immediately preceding analysis. Sample Analysis: Both fruit and wine samples were analysed for colour using a spectrophotometer at 520nm, primarily suited to analysing anthocyanins which make up the bulk of Pinot noir fruit and young wine. The spectrophotometer is a similar yet quantitative manner to the analysis of the human eye by the consumer. Michigan Pinot noir Fruit and Wine Extract Spectrophotometric Results, 2004 Michigan Pinot noir Fruit and Wine Extract Spectrophotometric Results, 2005 REFERENCES Gore M. G., 2000: Spectrophotometry and Spectrofluorimetry – a Practical Approach. Oxford University Press, Oxford. Jackson, R.S; 2000: Wine Science – Principals and Practices, Academic Press, Adalaide. Sacchi, K. L., Bisson, L. F. and Adams, D. O., 2005: A Review of the Effect of Winemaking Techniques on Phenolic Extraction in Red Wines. American Journal of Enology and Viticulture 56:3 197-206. Waterhouse, A. L. and Kennedy, J. A., 2004: Red Wine Colour: Revealing the Mysteries. American Chemical Society, Washington, D. C. 2005 Pinot noir Wines 2004 Pinot noir Wines