terclim by ICS banner
IVES 9 IVES Conference Series 9 HAZE RISK ASSESSMENT OF MUSCAT MUSTS AND WINES : WHICH LABORATORY TEST ALLOWS A RELIABLE ESTIMATION OF THE HEATWAVE REALITY?

HAZE RISK ASSESSMENT OF MUSCAT MUSTS AND WINES : WHICH LABORATORY TEST ALLOWS A RELIABLE ESTIMATION OF THE HEATWAVE REALITY?

Abstract

Wines made from Muscat d’Alexandria grapes exhibit a high haze risk. For this reason, they are systematically treated with bentonite, on the must and sometimes also on wine. In most oenological laboratories and in companies (trade, cooperatives, independent winegrowers), the test that is by far the most widely used, on a worldwide scale, remains the heat test at 80°C for 30 minutes to 2 hours (and some-times up to 6 hours). The tannin test (sometimes coupled with a heat treatment) and the Bentotest are still used. In this study, we show that all these tests give much higher estimates of the haze risk than the risk assessed by a 24-48h treatment at 42°C, which represents a heat wave. For this purpose, we performed heat treatments ranging from 40 to 80°C in order to find out which test best reflects a heat wave episode. Each of these tests was carried out at different heating times (kinetic approach) and with wines presenting risks of protein breakage ranging from low to high. The results show that : 1) the test at 50°C for 1h (in a water bath) is by far the most correlated with the haze appearing when the wine is spent 24-48h at 42°C and 2) this test has a safety margin to choose the most adapted protein stabilisation treatment. Conversely, treatment at 80°C gives very high turbidities. The direct consequence of the 80°C-heat test is the use of too high doses of bentonite to eliminate a risk that is in fact poorly assessed. In this study dedicated to Muscat from Spain (Catalunya) wines, we show that it is possible, by means of a 1-hour heat test at 50°C carried out in the laboratory, to decide on the most appropriate treatment. In concrete terms, this translates into the reduction of bentonite doses, but also into the possibility of using oenological alternatives to this treatment.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Richard Marchal¹, Pol Gimenez², Bertrand Robillard³, Fernando Zamora², Jacques-Emmanuel Barbier³, Thomas Sa-Lomon¹, Maria Isabel Araque Granados², Joan-Miquel Canals Bosch²

1. Faculté des Sciences de l’université de Reims Champagne-Ardenne, Laboratoire d’Oenologie, 51687 Reims CEDEX 02, France
2. Universitat Rovira i Virgili, Facultat d’Enologia, Campus Sescelades, 43007 Tarragona, Espagne
3. Institut Œnologique de Champagne – ZI de Mardeuil – 51201 ÉPERNAY Cedex, France

Contact the author*

Keywords

Haze risk, Muscat, wine, heat test

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

MONITOR SOME KEY PARAMETERS THROUGH THE IMPLEMENTATION OFCONTINUOUS CONTROL SYSTEMS OF THE MUST-WINE DURING MACERATION-FERMENTATION IN RED WINEMAKING TO MANAGE OPERATIONS IN “AUTOMATION”

This study is aimed to develop a complete tool for the winemaker with, complete and targeted “winemaking recipes” that can be adapted to criteria set by the winemaker, such as: grape variety, grape health status, degree of ripening, desired wine, redox status throughout the alcoholic fermentation.
To get such aim, specific sets of experiments using red grape juices from different varieties (Nebbiolo, Barbera, Pinot noir, etc.) collected at different technological and phenolic maturity points, will be held with “automatized 4.0 tanks” equipped with sensors for measuring: redox potential, dissolved oxygen, relative density, temperature, and color in order to collect a sufficient amount of data preparatory to the creation of operating models in the most widely winemaking situations in which the automatized 4.0 tanks “will be able to independently respond” with the right corrective actions (opening/closing aeration valve, execution/block pumping overs , etc.) if the key parameters exceed the limits of the recommended ranges set in the selected recipe.

AROMA AND SENSORY CHARACTERIZATION OF XINOMAVRO RED WINES FROM DIFFERENT GREEK PROTECTED DESIGNATIONS OF ORIGIN, EFFECT OF TERROIR CHARACTERISTICS

The quality of wines has often been associated with their geographical area of production. The aim of this work was to characterize Protected Designation of Origin (PDO) Xinomavro red wines from different geographical areas of Amyndeon and Naoussa in Northern Greece, elaborated with variables that contribute to their differentiation, such as soil characteristics, altitude, monthly average temperature and rainfall.
Xinomavro fruit parcels from different vineyards within the two PDO zones (5 PDO Naoussa and 6 PDO Amyndeon) were vinified following a standard winemaking process. A total of 25 aroma compounds were quantified using gas chromatography-mass spectrometry (GC-MS) with simultaneous full scan and selected ion monitoring for data recording, and odor activity values (OAVs) were determined.

PINKING PHENOMENA ON WHITE WINES: RELATION BETWEEN PINKING SUSCEPTIBILITY INDEX (PSI) AND WINE ANTHOCYANINS CONTENT

Pinking is the emergence of pink tones in white wines exclusively produced from white grape varieties, known as pinking phenomena for many years. Pinking is essentially appeared when white wines are produced under reducing conditions [1,2,3]. Pinking usually occurs after bottling and storage of white wines, but its appearance has also been described after alcoholic fermentation or even as soon as the grape must is extracted [4]. Therefore, the purpose of this work was to investigate the existence of an-thocyanins in white wines made from different white grape varieties and grown locations and critically evaluate the most common method used for predicting pinking appearance in white wines: the Pinking Susceptibility Index (PSI).

DOES LIGNIN AN ACCEPTABLE MARKER OF GRAPESEED MATURATION AND QUALITY?

Usually the winemaker consider polyphenols from the grape berry as an actor of the wine quality. There are frequently consider as a marker of grape maturity. It is commonly known that winemaker consider tannins and anthocyanins as main polyphenol actors for winemaking practices and wine quality. Here we will focus on the characterisation of lignins in grape seeds. Previous studies suggest that the seed is lignified [1], which could explain the change in colour of the seed when it reaches maturity and thus provide a reliable indicator for describing the maturity stage in the seed.

IMPACT OF MUST NITROGEN DEFICIENCY ON WHITE WINE COMPOSITION DEPENDING ON GRAPE VARIETY

Nitrogen (N) nutrition of the vineyard strongly influences the must and the wine compositions. Several chemical markers present in wine (i.e., proline, succinic acid, higher alcohols and phenolic compounds) have been proposed for the cultivar Chasselas, as indicators of N deficiency in the grape must at harvest [1]. Grape genetics potentially influences the impact of N deficiency on grape composition, as well as on the concentration of potential indicators in the wine. The goal of this study was to evaluate if the che- mical markers found in Chasselas wine can be extended for other white wines to indicate N deficiency in the grape must.