Project Number
WW 10-19
Project title
Preliminary survey of glucose:fructose ratios in grape must from the Western Cape wine growing region
Project leader
Jolly, N P
Team members
Olivier, R
Chotoomia, S
Manual, F M
Project description
Glucose to fructose imbalances during wine fermentation with the associated fermentation problems are prevalent in the South African wine industry. Various microbiological aspects pertaining to this problem are being investigated by various research groups. However, it is unknown what the glucose to fructose concentration is in grape must at the start of fermentation, especially in those grapes harvested at high sugars. This knowledge is important if fructophyllic yeasts (non-Saccharomyces) and lesser glucophyllic yeasts (some strains of S. cerevisiae) are to be used successfully during winemaking to address these imbalances. Current microbiological research projects are not specifically focussed on analysing grape musts. The whole issue around glucose and fructose management during fermentation is a complex task and numerous factors can play a role. However, a start needs to be made and this project therefore proposes to obtain a broad overview of glucose to fructose ratios in grape must in South African grape musts.
Presentation(s)
Jolly, N. 2007. The use of fructophyllic yeast for a co-inoculated fermentation of grape juice. Paper presented at the 8th International Symposium on Innovations in Enology. 22-23 April, Stuttgart, Germany.
Jolly, N. 2009. The management of glucose and fructose ratios in must during fermentation. Winetech / VinPro Information Day. 6 May, ARC Infruitec-Nietvoorbij, Stellenbosch, South Africa.