Early development of potential wine styles for PIWI varieties in grapevine breeding

Abstract

In a framework in which climate change is increasingly recognized as a critical global challenge, traditional viticulture must be reconsidered in order to provide better solutions for future needs [1]. Grapevine breeding plays a key role by developing new varieties that combine high wine quality potential with resistance to fungal diseases and better adaptation to the changing climatic conditions. In this context, resistant grapevine cultivars, so-called PIWIs (from the German word “Pilzwiderstandsfähig”), represent a promising solution to new challenges posed by climate change. While the successful introduction of disease resistance in PIWIs is already detectable few weeks after germination via marker-assisted selection (MAS), the assessment of a breeding strain to deliver grapes suitable for the production of high quality wines lasts decades. Standardized micro-vinification allows exploring the basic of wine quality potential from new variety candidates [2]. Consequently, this study aims to investigate the sensory wine profiles from new PIWIs by determining key sensory traits and evaluating their response to different winemaking techniques. Hereby, potential wine styles for new cultivars are identified in the later steps of the breeding program when sufficient grape material becomes available. Based on this, recommendations for pioneering winemakers can be provided to assist their market introduction. Three recently released white wine PIWIs: Calardis Musqué, Calardis Blanc and Calardis Soleil developed from the Julius Kuehn Institute were investigated. Small-scale experimental vinifications were carried out in 30 L steel tanks, with different winemaking processes that varied in skin contact time, fermentation temperature and fermentative yeast strains. Three different sensory evaluations were conducted using a panel of 20 trained tasters; first, a triangle test to establish discrimination among the wines, followed by two rapid and cost-effective methods: sorting and Napping® [3] and RATA (Rate-All-That-Apply) [4]. This study reveals first potential wine stylistics for the investigated PIWIs and show their sensory characteristics and plasticity induced by the different oenological treatments. This highlights their potential to produce high quality wines with various sensory profiles. Establishing such studies in the breeding process for promising candidate varieties will support the final breeding decision and provide an initial understanding of potential wine styles to support their introduction to the market.

References

[1] van Leeuwen, C., Sgubin, G., Bois, B. et al. (2024). Climate change impacts and adaptations of wine production. Nat Rev Earth Environ 5, 258–275.

[2] Töpfer, R., Trapp, O. (2022). A cool climate perspective on grapevine breeding: climate change and sustainability are driving forces for changing varieties in a traditional market. Theor Appl Genet 135, 3947–3960.

[3] McSweeney, M. (2024). Rapid and Cost-Effective Methods for Wine Sensory Profiling: Napping and Sorting. In: Pozo-Bayón, M.Á., Muñoz González, C. (eds) Wine Analysis and Testing Techniques. Methods and Protocols in Food Science. Springer, New York, NY

[4] Valentin, D., Brand, J., Sáenz-Navajas, M.P. (2024). Rapid and Cost-Effective Methods for Wine Profiling: CATA/RATA. In: Pozo-Bayón, M.Á., Muñoz González, C. (eds) Wine Analysis and Testing Techniques. Methods and Protocols in Food Science. Springer, New York, NY.