Potential climate change impacts on winegrape must density and titratable acidity in southwest Germany

Abstract

This research presents estimations for the development of must density and titratable acidity of wine produced during the 21st century in the federal state of Baden-Wuerttemberg in southwestern Germany. The estimations were based on 30 yr long records of climate data and vin- tages which were then used to initialize a statistical model. The results of the statistical model were used to estimate the must density and titratable acidity of future vintages based on data from climate simulation runs from 2 regional climate models: the regional climate model REMO with A1B and A2 emission scenarios and the climate version of the local model (CLM) with the A1B emission scenario. The estimation was made for the 30 yr periods 2011�2040, 2041�2070 and 2071�2100. An increase of must density and a decrease in titratable acidity for the viticultural dis- tricts of Baden and Wuerttemberg as well as for the Bodensee area were detected. The increase in must density from one 30 yr period to the next ranged from 4 to 7° Oechsle, and the decrease in titratable acidity ranged from 0.5 to 2 g l �1 . Changes of these magnitudes likely will endanger the quality of established brands without appropriate grower and winemaker adaptations. The results of this study provide a detailed description of possible forthcoming climate-driven impacts on must density and titratable acidity values which can assist viticulturalists in planning adaptations to those changes.