IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Significance of factors making Riesling an iconic grape variety

Significance of factors making Riesling an iconic grape variety

Abstract

Riesling is the iconic grape variety of Germany and accounts for 23% of the German viticulture acreage, which comprises 45% of the worldwide Riesling plantings. Riesling wines offer a wide array of styles from crisp sparkling wines to highly concentrated and sweet Trockenbeerenauslese or Icewines. However, its thin berry skin makes Riesling more vulnerable to detrimental environmental threats than other white wine varieties.

Trying to adapt Riesling to climate change we investigate how to mitigate premature Botrytis infections, the loss of quality and yield due to sunburn or increasing levels of TDN, which causes the unique petrol off-flavor. Weather variation from year to year necessitates an active acidity management, either diminishing acidity by skin maceration or use of lactic acid bacteria but also more recently lowering pH by ion exchange resins or malic acid producing yeast. A strong focus is to enhance intensity and diversity of Riesling aroma by viticultural and oenological measures, which are controlled by sophisticated chemical analysis including a measure of odorless precursors.

 Riesling is a highly transparent variety in respect to terroir, deviating strongly in odor and taste due to different bed rocks and soil types, micro climates and inclination of individual vineyards. Applying comprehensive stable isotope dilution analysis of volatiles and sensory evaluation we could demonstrate not only the sensory relevance of terroir, but also how stable these patterns were over five vintages and even individual winemaking measures. Using next generation gen- sequencing techniques to study spontaneous fermentations, we could also reveal the significant impact of site specific microbiomes.

 Riesling wines are highly acclaimed for their longevity due to their exciting balance of acidity and sweetness. Re-tasting terroir defined Riesling wines again after four years revealed the expected modification in sensory terms due to aging, but prove that the general differences among the specific terroir expressions were conserved through the maturation process.

 Many of these scientific puzzle pieces were successfully implemented by the Riesling producers over the last two decades and they succeeded to improve Riesling wines in each of its multitude of stylistic facets. However, it will be a challenge to preserve their unique and diverse characters in the course of progressive climate change

DOI:

Publication date: June 22, 2022

Issue: IVAS 2022

Type: Article

Authors

Ulrich Fischer¹*
¹Institute for Viticulture and Oenology, DLR Rheinpfalz, Breitenweg 71, 67435 Neustadt, Germany

Contact the author

Keywords

Riesling, aroma compounds and precursors, sensory evaluation, terroir, acidity management, ageing of wine

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Grapevine rootstock field evaluation under drought and saline condition in California

Climate change impacts grape production worldwide and in California drought and salinity became increasingly challenging for grape growers to maintain sustainable production and fruit quality.

Assessing the climate change vulnerability of European winegrowing regions by combining exposure, sensitivity and adaptive capacity indicators

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.

Methyl Jasmonate Versus Nano-Methyl Jasmonate: Effect On The Stilbene Content In Monastrell Variety

Stilbenes, a kind of non-flavonoid phenolic compounds, have been reported to be responsible for various beneficial effects. Their biological properties include antibacterial and antifungal effects, as well as cardioprotective, neuroprotective and anticancer actions (Guerrero et al. 2009).Several strategies can be used to increase stilbene content in grapes and one of them could be the use of elicitors such as methyl jasmonate. The use of this elicitor has been proven to be efficient in the production of secondary metabolites which increases the quality of wines, but its use also has some drawbacks such as its low water solubility, high volatility, and its expensive cost (Gil-Muñoz et al. 2021).

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Fast, and full microbiological wine analysis using triple cellular staining.

We propose here a brand new large routine microbiological analysis method intended for oenology, in flow cytometry, using high performance equipment and triple selective cell staining, activated by fluorescence. The results and practical applications of the method are presented: Brettanomyces (Dekkera) Monitoring, fermentations monitoring, bottling and enological practices monitoring.The method allow a complete new microbiological tool for wine industry.The method has been accredited ISO 17025 in our laboratories.