Significance of factors making Riesling an iconic grape variety

Making high quality but affordable Pinot noir (PN) wine is challenging in most terroirs and New Zealand’s (NZ) situation is no exception. To increase the probability of making highly typical PN wines producers choose to grow grapes in cool climates on lower fertility soils while adopting labour intensive practices. Stringent yield targets and higher input costs necessarily mean that PN wine cost is high, and profitability lower, in line-priced varietal wine ranges. To understand the reasons why higher yielding vines are perceived to produce wines of lower quality we have undertaken an extensive study of PN in NZ. Since 2018, we established a network of twelve trial sites in three NZ regions to find individual vines that produced acceptable commercial yields (above 2.5kg per vine) and wines of composition comparable to “Icon” labels. Approximately 20% of 660 grape lots (N = 135) were selected from within a narrow juice Total Soluble Solids (TSS) range and made into single vine wines under controlled conditions. Principal Component Analysis of the vine, berry, juice and wine parameters from three vintages found grape berry mass to be most effective clustering variable. As berry mass category decreased there was a systematic increase in the probability of higher berry red colour and total phenolics with a parallel increase in wine phenolics, changed aroma fraction and decreased juice amino acids. The influence of berry size on wine composition would appear stronger than the individual effects of vintage, region, vineyard or vine yield. Our observations support the hypothesis that it is possible to produce PN wines that fall within an “Icon” benchmark composition range at yields above 2.5kg per vine provided that the Leaf Area:Fruit Weight ratio is above 12cm2 per g, mean berry mass is below 1.2g and juice TSS is above 22°Brix.

The addition of fungal chitosan in wine is allowed since 2009 to release some spoilage microorganisms such as Brettanomyces bruxellensis (OIV/OENO 338A/2009; EC 53/2011). This yeast is able to produce volatil phenols and is responsible of organoleptic deviations compromising quality and typicality of red wines [1]. Despite the fact that fungal chitosan is highly renewable, no toxic and non-allergenic, its use remains marginal because this treatment is relatively recent (compare to sulphites treatment) and information are contradictory between different studies described in literature. For all these reasons,

A survey has been conducted on 32 students and 25 former students of 28 nationalities of an international master course training executives of the international Wine sector.

The shelf life of wine is a major concern for the wine industry. This is particularly true for wines intended for long cellaring, which are supposed to reach their peak after an ageing period ranging from a few months to several years, or even decades. Low, controlled oxygen inputs through the closure system are generally necessary for the wine to evolve towards its optimum organoleptic characteristics. Our previous studies have already shown that the interface between the cork and the bottleneck plays a crucial role in the transfer of oxygen into the bottled wine.

Il mal dell’esca é una malattia della vite della quale sono state studiate sintomatologia, eziologia, patogenesi ed epidemiologia. Essendo una malattia che colpisce soprattutto la parte epigea delle piante, le caratteristiche dei suoli non sono mai state considerate fra le responsabili della sua insorgenza e diffusione.