Sensory and aroma impact of mitigation strategies against sunburn in Riesling

Climate change is an environmental challenge that impacts the wine industry due to frequent sunburn damage triggered by heat waves, sun radiation and severe water deficits. This leads yield losses sensory changes in resulting wines, presumably caused climate-induced off-flavours. study aims develop viticultural oenological strategies mitigate highly sensitive variety Riesling its detrimental properties. In 2020, we combined timing intensity of defoliation measures with application kaolin calcium hydroxide suspensions, reflecting a portion solar radiation. Seven treatments were replicated three field experiments. Grapes from each replication maintained as fermentation and, therefore, separately vinified following standardised protocol. Replicates, including replicates, further used replications. Descriptive analysis (DA) temporal dominance sensations (TDS) revealed significant impact experimental trials eight twelve attributes. Additionally, wines analysed gas chromatography-mass spectrometry. The early exposition treatment partial grape zone after flowering, followed second at berry closure, reduced fruity aroma but increased smoky notes enhanced 4-vinylguajacol formation well atypical ageing note (ATA) reminiscent acacia blossom, naphthalene fusel alcohols. Applying or particles on skin slightly mitigated these unpleasant effects even fruitiness sweetness. Late closure diminished green note, which was most prominent non-defoliated control. Further smokiness ATA intensities lowered, contrast their rise defoliation. However, late 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN), causing petrol off-flavour. TDS higher sweet during first 10 seconds defoliation, while fostered dominant lingering sourness. conclusion, lowers incidence adaptation towards exposure, increases flavours diminishes fruitiness. These could be significantly applying skins.