terclim by ICS banner
IVES 9 IVES Conference Series 9 WINE RACKING IN THE WINERY AND THE USE OF INERT GASES: CONTROL AND OPTIMIZATION OF THE PROCESS

WINE RACKING IN THE WINERY AND THE USE OF INERT GASES: CONTROL AND OPTIMIZATION OF THE PROCESS

Abstract

Atmospheric oxygen (O₂) generates oxidation in wines that affect their physicochemical and sensory evolution. The O₂ uptake in the different winemaking processes is generally considered to be negative for the sensory characteristics of white and rosé wines. Wine racking is a critical point of O₂ uptake, as the large surface area of the wine exposed during this operation and the inability to maintain an effective inert gas blanket over it.

The aim was to study the uptake of O₂ during the racking of a model wine as a reference and to compare with purging the destination tank with different inert gases. In addition, inert gases were also used to protect the wine in the racking tank by blanketing the wine. Finally, a full-scale inerting study was carried out in a commercial winery during the racking of a white wine to evaluate the effectiveness of the use of different inert gases. Dissolved oxygen (DO) and Head Space Oxygen (HSO) was monitored in different points during the wine racking.

Purging an empty tank with different inert gases was effective being the CO₂:Ar (20:80) mixture clearly the most effective, requiring less gas volume to displace O₂. The opposite result was found with N₂ because it worked in dilution mode. Although from an economic viewpoint, the most recommendable gas was CO₂.

The level of protection of the racked wine and the headspace in the empty destination tank differed depending on the gas used and the thickness (% of the tank volume) of the blanket formed with each gas. Based on the results obtained, purging with 25% of the empty tank volume of each inert gas is recommended to protect racked wine in a good cost-benefit way. To keep the headspace of the racking tank inert, blanketing with 50% of tank volume of Ar, CO₂ or the mixture of both were sufficient. Applying different volumes of gas had little effect on the DO of the wine at the tank outlet.

The study of a white wine racking in a commercial winery demonstrated the greater efficacy of Ar versus N₂ in the purging of the destination tank, while for the hoses inerting, the differences between both gases were minor. In addition, Ar was able to maintain the wine at lower DO levels as well as to provide a higher level of HSO protection in the destination tank during the racking process.

The results obtained allow us to recommend the appropriate type and volume of inert gas to minimize O₂ uptake during wine racking.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Rubén Del Barrio-Galan¹, Maria Del Alamo-Sanza¹, Maria Asensio-Cuadrado², Elena Perez-Cardo¹, Marioli Ale-Jandra Carrasco-Quiroz¹, Ignacio Nevares².

1. Dpt. Química Analítica, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain.
2. Dpt. Ingeniería Agrícola y Forestal, UVaMOX-Group, Universidad de Valladolid, Avda. Madrid, 50, 34004 Palencia, Spain

Contact the author*

Keywords

Inert gases, racking wine, purging, blanketing, oxygen

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

EVALUATION OF THE OENOLOGICAL POTENTIAL OF NEW RESISTANT VARIETIES MEETING TYPICAL BORDEAUX CHARACTERISTICS

Varietal innovation is a major lever for meeting the challenges of the agro-ecological transition of vi-neyards and their adaptation to climate change. To date, selection work has already begun in the Bordeaux region through the Newvine project. The aim of this project is to create new vine varieties with resistance to mildew and powdery mildew, adapted to the climatic conditions of the Bordeaux region and enabling the production of wines that are in line with consumer tastes and the expected typicity of Bordeaux wines.

THE ODORIFEROUS VOLATILE CHEMICALS BEHIND THE OXIDATIVE AROMA DEGRADATION OF SPANISH RED WINES

It is a well-established fact that premature oxidation is noxious for wine aromatic quality and longevity. Although some oxidation-related aroma molecules have been previously identified, there are not works carrying out systematic research about the changes in the profiles of odour-active volatiles during wine oxidation.

GRAPE SPIRITS FOR PORT WINE PRODUCTION: SCREENING THEIR AROMA PROFILE

Port is a fortified wine, produced from grapes grown in the demarcated Douro region. The fortification process consists in the addition of a grape spirit (77% v/v) to the fermenting juice for fermentation interruption, resulting in remaining residual sugars in the wine and increased alcohol content (19-22%). The approval of grape spirits follows the Appellation (D.O. Port wine) rules1 and it is currently carried out based on analytical control and on sensory evaluation done by the public Institute that upholds the control of the quality of Douro Appellation wines. However, the producers of Port wines would like to have more information about quality markers of grape spirits.

WINE AS AN EMOTIONAL AND AESTHETIC OBJECT: IMPACT OF EXPERTISE

Wine tasting has been shown to provide emotions to tasters (Coste et al. 2018). How will expertise impact this emotional response? Burnham and Skilleås (2012) reported that the cultural, experiential, and aesthetic competencies characterize an expert in wine compared to a novice. Although there is no consensual definition of an aesthetic experience, Burnham and Skilleås (2012) reported that aesthetic appreciation is “disinterested, normative for others and communicable” in comparison to sensory pleasure.

FREE TERPENE RESPONSE OF ‘MOSCATO BIANCO’ VARIETY TO GRAPE COLD STORAGE

Temperature control is crucial in wine production, starting from grape harvest to the bottled wine storage. Climate change and global warming affect the timing of grape ripening, and harvesting is often done during hot summer days, influencing berry integrity, secondary metabolites potential, enzyme and oxidation phenomena, and even fermentation kinetics. To curb this phenomenon, pre-fermentative cold storage can help preserve the grapes and possibly increase the concentration of key secondary metabolites. In this study, the effect of grape pre-fermentative cold storage was assessed on the ‘Moscato bianco’ white grape cultivar, known for its varietal terpenes (65% of free terpenes represented by linalool and its derivatives) and widely used in Piedmont (Italy) to produce Asti DOCG wines.