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…

EFFECTS OF BIODYNAMIC VINEYARD MANAGEMENT ON GRAPE RIPENING MECHANISMS

Biodynamic agriculture, founded in 1924 by Rudolph Steiner, is a form of organic agriculture. Through a holistic approach, biodynamic agriculture seeks to preserve the diversity of agriculture and the existing interactions between the mineral world and the different components of the organic world. Biodynamic grape production involves the use of composts, herbal teas and mineral preparations such as 500, 501 and CBMT.
Several scientific studies have provided evidence on the effects of biodynamic farming on the soil, the plant and the wine. Numerous empirical opinions of wine growers support the existence of differences brought by such a management.

‘TROPICAL’ POLYFUNCTIONAL THIOLS AND THEIR ROLE IN AUSTRALIAN RED WINES

Following anecdotal evidence of unwanted ‘tropical’ character in red wines resulting from vineyard interventions and a subsequent yeast trial observing higher ‘red fruit’ character correlated with higher thiol concentrations, the role of polyfunctional thiols in commercial Australian red wines was investigated.
First, trials into the known tropical thiol modulation technique of foliar applications of sulfur and urea were conducted in parallel on Chardonnay and Shiraz.1 The Chardonnay wines showed expected results with elevated concentrations of 3-sulfanylhexanol (3-SH) and 3-sulfanylhexyl acetate (3-SHA), whereas the Shiraz wines lacked 3-SHA. Furthermore, the Shiraz wines were described as ‘drain’ (known as ‘reductive’ aroma character) during sensory evaluation although they did not contain thiols traditionally associated with ‘reductive’ thiols (H2S, methanethiol etc.).

HYDROXYTYROSOL PRODUCTION BY DIFFERENT YEAST STRAINS: SACCHAROMYCES AND NON-SACCHAROMYCES AND THE RELATION WITH THE NITROGEN CONSUMPTION

Hydroxytyrosol (HT) is a phenolic compound with extensive bioactive properties. It is present in olives, olive oil and wines. Its occurrence in wines is partly due to yeast synthetise tyrosol from tyrosine by the Ehrlich pathway, which is subsequently hydroxylated to .
The aim of the present work is to study how different yeast strains can influence in the HT production and, how the different nitrogen consumption of each strain can interfere the production of bioactive compounds.

PRODUCTION OF A FUNCTIONAL BEVERAGE FROM WINEMAKING BY-PRODUCTS: A NEW WAY OF VALORISATION

In the challenge of transforming waste into useful products that can be re-used in a circular economy perspective, winery by-products can be considered as a source of potentially bioactive molecules such as polyphenols. The wine industry generates each year 20 million tons of by-products. Kombucha fermentation is an ancestral process which allow to increase the biological properties of tea by the action of a microbial consortium formed by yeasts and bacteria called SCOBY. It belongs to the field of healthy food for which the interest of consumers is growing. The objective of this work was to propose a new functional beverage made from winemaking by-products fermented by a Kombucha SCOBY.

SIP and save the planet: a sensory and consumer exploration of australian wines made from potentially drought-tolerant white wine grapes

In order to attenuate the effects of climate change on the ability to cultivate quality wine grape vines in Australia, it is essential to adapt to the projected less favourable Australian climate scenarios. One response may be to convert a portion of the current grapevine plantings to those varieties that demand less water and can tolerate increased heat. This investigation aimed to (i) generate sensory profiles and (ii) obtain knowledge about Australian wine consumers’ preferences and opinions of Australian wines made from potentially drought tolerant, white wine grape varieties not traditionally cultivated in Australia. A Rate-All-That-Apply (RATA) sensory panel (n = 49) generated sensory profiles of 44 commercial white wines made from 7 different white grape varieties (Arinto, Fiano, Garganega, Greco, Verdejo, Verdelho and Vermentino), plus two benchmark examples each of an Australian Riesling, Pinot Gris and Chardonnay wine.