Association of selected viniviticultural factors with sensory and chemical characteristics of New Zealand Sauvignon blanc wines

- We investigate flavour and chemical composition of Sauvignon blanc wines.
- Sensory and chemical characterstics differed as a function of type of grape harvesting.
- Machine-harvested fruit wines were evaluated more positively than hand-harvested fruit wines.

The major aim of this study was to investigate associations between selected grape-growing and winemaking factors and sensory and chemical characterisation of Sauvignon blanc wines from New Zealand. Thirteen commercial Sauvignon blanc wines produced by the same wine-making team were assessed. The 13 wines included several produced under 'standard' Marlborough wine-production conditions from machine-harvested fruit, whilst other wines were produced from hand-harvested fruit, each exemplifying a particular viticultural (e.g., location) or oenological (use of oak) factor assumed to influence wine composition and sensory profile. The wines were evaluated organoleptically via several sensory methods (sorting; descriptive rating) by 28 New Zealand wine professionals. Varietal impact compounds, 3-mercaptohexan-1-ol (3MH), 3-mercaptohexyl acetate (3MHA), 4-mercapto-4-methylpentan-2-one (4MMP), and 3-isobutyl-2-methoxypyrazine (IBMP) were quantified in each wine. We show that machine-harvested-fruit wines had significantly elevated concentrations of 3MH and 3MHA, and were perceived overall as fruitier, less acidic, and as having better concentration, balance and persistence in mouth than the Sauvignon wines made from hand-harvested fruit. The Sauvignon blanc wine produced by indigenous fermentation in older oak was rated significantly higher in perceived intensity, length, palate weight, and balance than most of the other wines. The study demonstrated that vineyard location, row orientation, type of grape processing at harvest, and oenological manipulations provide means for influencing sensory profile and chemical composition of Sauvignon wines.