OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Analysis and composition of grapes, wines, wine spirits 9 Impact of press fractioning on Pinot noir and Pinot meunier grape juice and wine compositions and colour

Impact of press fractioning on Pinot noir and Pinot meunier grape juice and wine compositions and colour

Abstract

The separation of different grape juice press fractions is an important step in the production of sparkling base wines. A complete press cycle for this style of wine is a series of pressure increases (squeezes) resulting in variations in juice composition during the press cycle. After alcoholic fermentation, wines obtained from grape juices also exhibit strong differences for numerous characteristics. Nevertheless, there is no statistical study of the impact of the press cycle on grape juices and wine colour/composition. So, the aim of this study (vintage 2018) was to investigate the changes in composition and colour parameters of Pinot noir and Pinot meunier grapes juices, as well as their corresponding wines, during the pressing cycle.

The studied parameters were: L*a*b*, A420, pH, total acidity (TA), malic and tartaric acids, sugars, maturity index, YAN, NH4+, a-NH2, Ca++ and K+ for the 23 grape juices, and pH, TA, malic and tartaric acids, alcohol, a-NH2, Ca++ and K+ for the 23 base wines. Results were analysed by Pearson’s correlation test, ANOVA and PCA after normalization of the data.

For examples, the TA and the tartaric acid content of the musts statistically decreased by 35 % and 41 % respectively between the beginning and the end of the press cycle, whilst the pH increased by 0.4 unit. These changes were observed concomitantly with the increases of a* and b* values by 4 to 6 units and a significant decrease of the luminosity L*. These observations were still true for wines. Many Pearson’s correlation coefficients were higher than 0.85 and even higher than 0.95 for some of them. The different PCAs considering the colour parameters, the acidity parameters or all of the parameters measured showed a strong separation of the samples according to the different squeezes, for grape juices as well as for the wines. This was confirmed with the PCA considering the 23 grape juices, the 23 wines and all of the parameters measured both in juice and wines.

conclusion:

As a conclusion, this study brings a greater understanding of: 1) Pinot noir and Pinot meunier must composition and colour changes all along the press cycle, 2) differences between wines produced with these grape juice fractions, 3) correlation between grape juice and wine compositions. These results could be a good tool for winemakers to decide how to separate the grape juice fractions during the pressing cycle to produce different styles of wines with different sensory qualities and aging potential.

DOI:

Publication date: June 23, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Richard Marchal

Faculté des Sciences de Reims BP1039 51687 Reims Cedex 02  

Contact the author

Keywords

Press fractioning, grape juice, sparkling base wine colour, ACP 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Sunburn results from a combination of excessive photosynthetically active radiation (PAR) and UV radiation and temperature that can be exacerbated by other stress factors such as water deficit. Sunburn is a physiological disorder that affects the visual and organoleptic properties of grapes. The appearance of brown and necrotic spots severely affects the commercial value of the fruit, and in extreme cases, significantly decreases yield. This damage occurs with some frequency in sensitive varieties such as Graciano.

The colour pattern of flower arrangements influence wine tasters’ sensory description

The arrangements of flowers and wine counterparts are inextricably linked. Whether a fundamental aspect of tablescaping or acolytes to broader entertainment rituals, they have an entangled history since ancient times. The aim of this contribution is to verify the influence of visually delicate and robust flower arrangements on individual description of wines. Changes in the sensory description of wines were investigated during subjects’ (thirty-two participants) exposure to three different conditions: the presence of delicate, robust, or totally absent flower arrangements. In each condition, the same two wines were blind tasted: a wine previously defined as delicate – a Pinot Noir from Australia, and a wine known for its robust character – a Tannat from Uruguay.

Comparative studies on the dynamics of fermentation of selected wine yeasts

Alcoholic fermentation is an anaerobic biochemical process of oxidation-reduction in which carbohydrates are metabolized by the action of yeast enzymes in major products

Climate change impacts: a multi-stress issue

With the aim of producing premium wines, it is admitted that moderate environmental stresses may contribute to the accumulation of compounds of interest in grapes. However the ongoing climate change, with the appearance of more limiting conditions of production is a major concern for the wine industry economic. Will it be possible to maintain the vineyards in place, to preserve the current grape varieties and how should we anticipate the adaptation measures to ensure the sustainability of vineyards? In this context, the question of the responses and adaptation of grapevine to abiotic stresses becomes a major scientific issue to tackle. An abiotic stress can be defined as the effect of a specific factor of the physico-chemical environment of the plants (temperature, availability of water and minerals, light, etc.) which reduces growth, and for a crop such as the vine, the yield, the composition of the fruits and the sustainability of the plants. Water stress is in many minds, but a systemic vision is essential for at least two reasons. The first reason is that in natural environments, a single factor is rarely limiting, and plants have to deal with a combination of constraints, as for example heat and drought, both in time and at a given time. The second reason is that plants, including grapevine, have central mechanisms of stress responses, as redox regulatory pathways, that play an important role in adaptation and survival. Here we will review the most recent studies dealing with this issue to provide a better understanding of the grapevine responses to a combination of environmental constraints and of the underlying regulatory pathways, which may be very helpful to design more adapted solutions to cope with climate change.

Impact of urbanization on optimum wine Terroirs in the Bordeaux region sample of one township of the Entre-Deux-Mers Area

L’étude présentée porte sur une commune de l’Entre-Deux-Mers dans le bordelais. Nous caractérisons dans un premier temps les potentialités des sols vis-à-vis de la production de vins rouges de qualité (délimitation de terroirs grâce à la prise en compte des couvertures pédologiques et des caractéristiques morphométriques du terrain : pentes, expositions, convexités. Dans un second temps, nous récapitulons l’évolution historique des occupations des sols depuis 1790 : l’emplacement des vignes est ainsi localisé sur les terroirs respectifs des communes. Enfin, une étude prospective résultant d’enquêtes sur l’utilisation du foncier, situe le devenir prévisible de l’espace étudié (en particulier dans ses composantes viticoles et urbaines).