Impact of climate change on grape cluster structure, grape constituents, and processability

Over the last 20 years in the Pfalz region of Germany, GDD were highest in the vintages 2018-2020. To visualize the effect of climate change for the Pfalz region of Germany, the development of TSS and TAwere documented during Pinot noir grape ripening for the vintages 1998-2021. It was observed that climate change causes sooner and accelerated ripening, however, sooner or accelerated ripening were not connected with each other. The presented study investigated the impact of vintages on berry physiology development, ripening heterogeneity in grape clusters, changes in grape constituent concentrations and their extractability with progressing grape maturity. Pinot noir and Cabernet Sauvignon, both cultivated in the Pfalz region, were compared during three consecutive vintages. Different maturities were considered in the range of 17-25 Brix and berry size distribution was documented. The changes in grape constituent concentrations and their extractability with progressing grape maturity were analyzed using HPLC-DAD/FD, LC-QToF-MS and protein precipitation assay. It was revealed that tannin extractability differs for grape varieties and vintages and progressing maturity seemed to have only a small influence on the extractability of anthocyanins