WAC 2022 banner
IVES 9 IVES Conference Series 9 WAC 9 WAC 2022 9 3 - WAC - Posters 9 Which heat test can realistically estimate white wine haze risk?

Which heat test can realistically estimate white wine haze risk?

Abstract

Different heat tests are used to predict the dose of bentonite necessary to prevent wine haze after bottling. The most used tests are 60-120 min. at 80°C. Nevertheless, there is a lack of information about the relationship between these tests and the turbidities observed in the bottles after the storage/transport of the wines in realistic conditions, when temperatures reach 35-42°C during 3-12 days.

In this study, 6 heat tests were applied on 14 Sauvignon wines (France) : 5-30-60 min. at 80°C and  30-60-120 min. at 50°C. The results were compared with the turbidity reached by the wines under real Summer conditions, i.e temperatures corresponding to heat waves (35 to 46°C, from 1 to 14 days) and representing 6 tests too. The 66 Pearson correlation coefficients (PCC) were calculated for all of these 12 heat tests when compared two by two.

The turbidities of the wines subjected to Summer temperature conditions (1 day at 35°C, 4 days at 35°C, 4 days at 35°C + 1 day at 43°C) were highly correlated with the turbidities developed by the Sauvignon wines after heating 30 or 60 min.  at 50°C. The PCC were between 0.980 and 0.989. The higher PCC were observed between Summer realistic conditions and a heat test during 120 min. at 50°C with PCC values between 0.993 and 0.997. The PCC between Summer heatings and a heat test during 60 min. at 80°C were interesting (0.911-0.924) but not so high.

Beyond these relationships, it is essential for a winemaker to consider the turbidity reached by the wine after a heat test. The problem is that turbidities observed for a wine after different heat tests can reach 2, 8 and 34 NTU when the wine was heated a 4 days at 35°C+ 1 day at 43°C, 2hrs at 50°C and 1hr at 80°C respectively. In these conditions, it is very problematic to decide what is the correct dose of bentonite to ensure a complete colloidal stability with time of the wine.

Proteins implicated in the white wine haze are essentially thaumatin-like proteins (TLPs) and chitinases whose temperatures of denaturation are around 55°C and 62°C respectively. It explains why the heat tests at 80°C, even if correlated with realistic tests give excessively high values when compared with what can happen to a wine during a hot Summer. This leads the winemaker to use excessive bentonite doses given stripped wines whilst lower doses could be sufficient to ensure the absence of haze in the bottle.

DOI:

Publication date: June 27, 2022

Issue: WAC 2022

Type: Article

Authors

RICHARD MARCHAL, Thomas Salmon, Marine Lecomte, Bertrand Robillard

Presenting author

RICHARD MARCHAL – University of Reims Champagne-Ardenne – University of Haute-Alsace

University of Reims Champagne-Ardenne – University of Haute-Alsace | University of Reims Champagne-Ardenne – University of Haute-Alsace | Institut Oenologique de Champagne

Contact the author

Keywords

Haze risk, protein, white wine, Sauvignon, Gewurztraminer

Tags

IVES Conference Series | WAC 2022

Citation

Related articles…

Leaf elemental composition in a replicated hybrid grape progeny grown in distinct climates

The elemental composition (the ionome) of grape leaves is an important indicator of nutritional
health, but its genetic architecture has received limited scientific attention. In this study, we
analyzed the leaf ionome of 131 interspecific F1 hybrid progeny from a Vitis rupestris (♀) X Vitis
riparia (♂) cross. The progeny were replicated in New York, South Dakota, Southwest Missouri ad Central Missouri, and the concentration of 20 elements were measured in their leaves at
three different phenological stages during the growing season. In leaves collected at the apical node at anthesis, elemental concentrations correlated in a consistent manner (p < 0.05) across all four geographic locations. In subsequent phenological stages, elemental ratios in the apical-node leaves remained consistent across the South Dakota and New York sites, but not across the Missouri sites. In leaves collected at the basal and middle nodes, correlations varied greatly across all locations.

Vineyard Landscape in Vale dos Vinhedos: Pressure and Protection

The region with Origin Indication Vale dos Vinhedos (IPVV) is located in the cities of Bento Gonçalves, Garibaldi and Monte Belo do Sul. It was established in November 2002, through an act of Instituto Nacional de Propriedade Industrial, according to Resolução INPI Nº. 75, of 2000, and Law Nº. 9.279 of 1996. The changes on the grape growing and wine making in the last 15 years, with the expansion of grapevines Vitis viníferas cultivation, the installation of several modern family wine companies, making wine with competitive quality, among other aspects, have enabled the implementation of concepts of Geographical Indications.

Defining the mechanisms and impact of winemaking treatments on tannin and polysaccharides in red wine: recent progress in creating diverse styles

Tannin and polysaccharide concentration and composition is important in defining the texture of red wines, but can vary due to factors such as cultivar, region, grape ripeness, viticultural practices and winemaking techniques. However, the concentration and composition of these macromolecules is dependent not only on grape tannin and polysaccharide concentration and composition, but also their extractability and, in the case of polysaccharides, their formation by yeast. Through studies into the influence of grape maturity, winemaking and sensory impacts of red grape polysaccharides, seed and skin tannins, recent research in our laboratory has shown that the processes involved in the extraction of these macromolecules from grapes and their retention in wine are very complex.

Volatile Organic Compound markers of Botrytis cinerea infection in artificially inoculated intact grape berries

The addition of partially dehydrated grapes to enrich must composition for producing complex dry/sweet wines represents a traditional practice in several regions of the world. However, the environmental conditions of dehydration chambers may facilitate the infection of Botrytis cinerea Pers. by promoting disease and provoking large grape losses. B. cinerea attack can induce alterations in the profile of volatile organic compounds (VOCs), which could be detected by sensors specifically trained to detect infection/disease-related compounds. These sensors could facilitate the early detection of the infection, consequently allowing to adjust some dehydration parameters.

Rootstock effect on Cabernet Sauvignon aromatic and chemical composition

Grape quality potential for wine production is strongly influenced by environmental parameters and agronomic factors. Several studies underline the rootstock effect on scions vegetative growth and berry composition [1] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Moreover, little is known about the effect of rootstock genetic variability on the aromatic composition in wines.