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…

EVALUATION OF INDIGENOUS CANADIAN YEAST STRAINS AS WINE STARTER CULTURES ON PILOT SCALE FERMENTATIONS

The interactions between geographical and biotic factors, along with the winemaking process, influence the composition and sensorial characteristics of wine¹. In addition to the primary end products of alcoholic fermentation, many secondary metabolites contribute to wine flavor and aroma and their production depends predominantly on the yeast strain carrying out the fermentation. Commercially available strains of S. cerevisiae help improve the reproducibility and predictability of wine quality. However, most commercial wine strains available on the market have been isolated from Europe, are genetically similar, and may not be the ideal strain to reflect the terroir of Canadian vineyards².

Read More

SENSORY PROFILES AND EUROPEAN CONSUMER PREFERENCE RELATED TOAROMA AND PHENOLIC COMPOSITION OF WINES MADE FROM FUNGUSRESISTANT GRAPE VARIETIES (PIWI)

Planting grape varieties with several resistance loci towards powdery and downy mildew reduces the use of fungicides significantly. These fungus resistant or PIWI varieties (acronym of German Pilzwiderstandsfähig) contribute significantly to the 50% pesticide reduction goal, set by the European Green Deal for 2030. However, wine growers hesitate to plant PIWIs as they lack experience in vinification and are uncertain, how consumer accept and buy wines from these yet mostly unknown varieties. Grapes from four white and three red PIWI varieties were vinified in three vintages to obtain four diffe-rent white and red wine styles, respectively plus one rosé.

Read More

CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF A POLYPHENOLIC EXTRACT OBTAINED BY GREEN SUPERCRITICAL CO₂ EXTRACTION FROM RED GRAPE POMACE

Upgrading wine industry solid wastes is considered as one of the main strategies to support the circular economy. Red grape pomaces constitute a rich source of polyphenols, which have been shown to possess antioxidant properties and to provide benefits for human and animal health. The objective of this work was to obtain and characterise polyphenolic extracts from red grape pomaces via green supercritical CO₂ extraction using ethanol as a co-solvent, and to evaluate their antibacterial activity against susceptible and multidrug-resistant Escherichia coli strains of animal intestinal origin.

Read More

AGING PATTERNS OF VARIETAL VOLATILE PROFILES OF WHITE WINES: A CASE STUDY ON 18 ITALIAN VARIETAL WHITE WINES

During wine aging many compositional changes take place. In particular, aroma undergoes dramatic modifications through a wide range of reactions that to date are only partly understood. Italy owns one of the largest ampelographic heritages worldwide, with over three-hundred different varieties. Among these, many white grapes are employed for the production of dry still white wines. Some of these wines are consumed young while others are more prone to aging. For many of these wines, the aging patterns related to volatile composition are still unknown.

Read More

CHARACTERIZATION OF ENOLOGICAL OAK TANNIN EXTRACTS BY MULTI-ANALYTICAL METHODS APPROACH

Oak tannin extracts are commonly used to improve wine properties. The main polyphenols found in oak wood extracts are ellagitannins¹ that release ellagic acid upon hydrolysis and comprise numerous structures². Moreover, oak tannin extracts contain other compounds giving a complex mixture. Consequently, the official OIV method based on gravimetric analysis of the tannin fraction adsorbed on polyvinylpolypyrrolidone is not sufficient to describe their composition and highlight their chemical diversity.

Read More