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: November 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

Citation

Related articles…

Targeted and untargeted 1H-NMR analysis for sparkling wine’s authenticity

Studies on wineomics (wine’s metabolome) have increased considerably over the last two decades. Wine results from many environmental, human and biological factors leading to a specific metabolome for each terroir. NMR metabolomics is a particularly effective tool for studying the metabolome since it allows the rapid and simultaneous detection of major compounds from several chemical families.1 Quantitative NMR has already proven its effectiveness in monitoring the authenticity of still wines.

Read More

Influence of dehydration and maceration conditions on VOCs composition and olfactory profile of Moscato Bianco passito sweet wine

Among the Vitis vinifera L. cv. Moscato, Moscato Bianco is the oldest and most cultivated one in Europe (1). According to the OIV Focus 2015, Italy is the country with the largest cultivated area of Moscato Bianco with about 12500 hectares (2), that is used to produce well-known wines (i.e., Moscato Passito in Piedmont, Moscato di Trani in Puglia, and Moscatello di Montalcino in Tuscany), mainly obtained from partially dehydrated grapes (1). Different dehydration techniques can strongly modify the chemical compounds of oenological interest, among which Volatile Organic Compounds (VOCs) (1) that are the main responsible for the varietal sensory character of the final wine.

Read More

Intelligent use of ethanol for the direct quantitative determination of volatile compounds in spirit drinks

The quality of any alcoholic beverage depends on many parameters, such as cultivars, harvesting time, fermentation, distillation technology used, quality and type of wooden barrels (in case of matured drinks), etc.; however, the most important factor in their classification is content of volatile compounds.

Read More

Potential deacidifying role of a commercial chitosan: impact on pH, titratable acidity, and organic acids in model solutions and white wine

Chitin is the main structural component of a large number of organisms (i.e., mollusks, insects, crustaceans, fungi, algae), and marine invertebrates including crabs and shrimps.

Read More

Berry maturity effects on physic and chemical characteristics of traditional sparkling wines produced from Chardonnay and Sauvignon blanc grapes.

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

Read More