Macrowine 2021
IVES 9 IVES Conference Series 9 Tannin potential and molecular toasting in cooperage: a tool to modulate fruity expression of red wine

Tannin potential and molecular toasting in cooperage: a tool to modulate fruity expression of red wine

Abstract

AIM: Oak wood play traditionally a huge role in making fine red wines. During wine maturation, barrel yields some of its constituents to the wine and leads to the improvement of its quality, contributing to richness and complexity [1]. From an aromatic point of view, the use of oak leads to the accentuation of easily recognizable woody notes, but also to a change in the perception of wine fruity character [2]. The objective of this work is to define how barrels, according to oak tannin levels and their toasting process, may impact the fruity aromatic perception of a Bordeaux red wine.

METHODS: Experimentation was performed in an AOP Margaux estate, Bordeaux area, on a 2018 Cabernet-Sauvignon red wine. Wine was stored in barrels for 12 months. Barrels with different oak wood tannin potential and toasting levels (13 modalities, duplicate; 26 barrels and a control in tank) were used. Various analytical analysis were realised to evaluate oak wood compounds and wine fruity ester contents. Sensory profiles were also assessed to evaluate fruity notes perception.

RESULTS: Some wood volatiles were impacted according to wood tannin potential and toasting levels. As expected, compounds with smoky and spicy notes increased with the heaviest toasting. Some furfural derivatives or aldehyde phenols were also correlated with toasting or potential tannin levels. Sensory analysis revealed a preservation of fruity notes of wines for barrels of lower tannin potential whereas woody descriptors were more perceived when barrel tannin potential increased.

Conclusions:

The increase in barrel tannin potential accentuated the woody compound levels as well as the woody perception in wine. A preservation of wines fruity aromatic expression seemed to be linked with the use of low tannin potential wood evaluated.

 

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Cameleyre Margaux

¹Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, Université de Bordeaux, F33882 Villenave d’Ornon France,G. LYTRA1, J-C. VICARD2, J-C. BARBE1 1Unité de recherche Œnologie, EA 4577, USC 1366 INRAE, ISVV, Université de Bordeaux, F33882 Villenave d’Ornon France 2Tonnellerie Vicard, 184 Rue Haute de Crouin, 16100 Cognac, France

Contact the author

Citation

Related articles…

Identification, quantification and organoleptic impact of « dried fruit » molecular markers in Merlot and Cabernet Sauvignon grapes and in red wines

The aromas found in young Bordeaux red wines made with Merlot and Cabernet Sauvignon suggest a complex mixture of aromas of fresh red fruits such as cherry or blackberry for Merlot, and strawberry or blackcurrant for Cabernet Sauvignon. The aromas of these wines are closely linked with the maturity of the grapes. The climate change that has occurred during the last decade in Bordeaux has induced changes in the ripening conditions of grape berries. It is now widely admitted that over-ripening of the berries during hot and dry summers results in the development of characteristic flavors reminiscent of cooked fruits (fig, prune). The presence of these overriding odors found in both musts and young wines affects the quality and subtlety of the wine flavor and may shorten its shelf life.

Influence of agrophotovoltaic on vine and must in a cool climate

The current energy crisis means that interest in agrophotovoltaics has increased significantly. The reason behind this is that the system aims to combine agricultural production with energy production. During the three-year period from 2020 to 2022, the effects of photovoltaic panels on the vine, the yield and the quality of the must were studied in Walenstadt in northern Switzerland, an area with a cool, humid climate. 65 Pinot noir vines were planted in the 160m2 study area. Because of the large edge effects, only 3 repetitions with 4 vines each could be created. A significantly lower leaf infestation by Plasmopara viticola was observed among the panels in each of the three years.

High throughput winter pruning weight estimation based on wood volume evaluation 

There is currently a real need to improve and speed-up phenotyping in experimental set-ups to increase the number of modalities studied. Accurate information acquisition on plant status with high-throughput capacity is the main appeal of on-board systems.
A proximal sensing camera for a proxy of winter pruning weight was tested. We estimated the shoot volume of the vine by image analysis using algorithms that integrate the local shoot section area estimate along the shoot skeleton obtained by a morphological distance transform.
The study was carried out on the GreffAdapt experimental vineyard in Guyot simple training and a canopy management using vertical trellising. The planting density is 6250 vines/ha with a row spacing of 1.6×1m. Five scions grafted onto 55 rootstocks are present and the combination rootstock×scion is different every five plants.

Effect of multi-level and multi-scale spectral data source on vineyard state assessment

Currently, the main goal of agriculture is to promote the resilience of agricultural systems in a sustainable way through the improvement of use efficiency of farm resources, increasing crop yield and quality under climate change conditions. This last is expected to drastically modify plant growth, with possible negative effects, especially in arid and semi-arid regions of Europe on the viticultural sector. In this context, the monitoring of spatial behavior of grapevine during the growing season represents an opportunity to improve the plant management, winegrowers’ incomes, and to preserve the environmental health, but it has additional costs for the farmer. Nowadays, UAS equipped with a VIS-NIR multispectral camera (blue, green, red, red-edge, and NIR) represents a good and relatively cheap solution to assess plant status spatial information (by means of a limited set of spectral vegetation indices), representing important support in precision agriculture management during the growing season. While differences between UAS-based multispectral imagery and point-based spectroscopy are well discussed in the literature, their impact on plant status estimation by vegetation indices is not completely investigated in depth. The aim of this study was to assess the performance level of UAS-based multispectral (5 bands across 450-800nm spectral region with a spatial resolution of 5cm) imagery, reconstructed high-resolution satellite (Sentinel-2A) multispectral imagery (13 bands across 400-2500 nm with spatial resolution of <2 m) through Convolutional Neural Network (CNN) approach, and point-based field spectroscopy (collecting 600 wavelengths across 400-1000 nm spectral region with a surface footprint of 1-2 cm) in a plant status estimation application, and then, using Bayesian regularization artificial neural network for leaf chlorophyll content (LCC) and plant water status (LWP) prediction. The test site is a Greco vineyard of southern Italy, where detailed and precise records on soil and atmosphere systems, in-vivo plant monitoring of eco-physiological parameters have been conducted.

Preliminary field studies of resistance of Georgian grapevine germplasm to powdery mildew (Erysiphe necator)

Erysiphe necator Schwein is a fungus that causes grapevine powdery mildew. It is one of the most problematic pathogens attacking Vitis vinifera L. The pathogen infects all green parts of the plant and reduces grape yield and quality. The suppression on mildew-susceptible cultivars requires intensive use of fungicides against pathogen, which has negative impact on the environment and human health.