2025 Post-Veraison in Pennsylvania - October 21

Report #8, Samples taken the week of October 13, 2025

This is the eighth, and final, weekly report for the third season of Post-Veraison in Pennsylvania (PVIP), a grape maturation reporting system across Pennsylvania vineyards. Reports consist of weekly grape ripening updates from cultivars that are planted widely across Pennsylvania (PA) vineyards (as based on feedback documented within Cultivars in the Commonwealth). Henceforth, PVIP reports will review the ripening patterns of some, or all, of the following cultivars: Cabernet franc, Chambourcin, Chardonnay, Riesling, and Vidal blanc. Due to the time required for grape samples to be shipped, processed, and measured, weekly reports will reflect maturation from the previous week. Participating stakeholders for the 2025 edition of PVIP manage vineyards in the following Pennsylvania counties: Chester, Erie, Fayette, Lehigh, and Snyder; thanks to these stakeholders for their participation and collaboration on this project. If you have a commercial vineyard in Pennsylvania, please let us know if you are interested in participating in a future edition of PVIP.

Note that these fruit samples are sent in from commercial vineyards; due to sampling methods and other factors, the samples may not necessarily represent the overall maturity of each cultivar across the entire block. These reports are meant to provide updates on general trends; some fluctuation from "anticipated ripening trends" in metabolites will be expected. Nonetheless, trends over time should give a good depiction of wine grape maturation across Pennsylvania. To date, Cabernet Franc has been harvested in Chester, Fayette, and Snyder Counties; Chambourcin in Chester and Snyder Counties; Chardonnay in Lehigh and Snyder Counties; Riesling in Chester and Fayette Counties; and Vidal blanc in Snyder County. Additionally, since the receipt of grape samples for this report, there were plans to harvest most of the cultivars in Erie.

Cabernet Franc samples collected during the week of October 13 were only collected from Erie and Lehigh Counties, as Cabernet Franc was harvested in other counties. Samples collected the week of October 6 indicated that fruit maturity was more advanced in Lehigh County relative to Erie County (Figure 1). Compared to the previous week's fruit composition in Erie, Brix decreased (-3.7°), pH decreased (-0.20), and titratable acidity (TA) remained the same. In Lehigh, however, fruit composition advanced toward harvest, as Brix increased (+2.4°), pH increased (+0.47), and TA decreased (-2.25 g/L).

Samples collected during the week of October 13 indicated that Chambourcin was more mature in Fayette County than in Erie County, as reflected by the greater Brix and pH, and lower TA, in Fayette County (Table 1). Compared to the previous week's samples, Brix increased by 0.8° in Erie County and 1.5° in Fayette County; pH increased by 0.17 in Erie and minimally changed in Fayette; TA decreased by 1.20 g/L in Erie County and 1.80 g/L in Fayette County. The only Riesling and Vidal blanc samples received last week were from Erie County. Relative to last week's samples, all primary metabolites in Riesling showed progress towards maturation – an increase in Brix (+3.2°), an increase in pH (0.22), and a decrease in TA (-0.75 g/L). However, the only primary metabolite in Vidal blanc that showed progress towards maturity was TA, which decreased by 2.70 g/L relative to the previous week's samples; Brix decreased by 3.0° and pH remained unchanged relative to last week's samples.

Pennsylvania stakeholders have reported harvest for the following cultivars in the 2025 vintage: Albariño, Aromella, Cabernet Dorsa, Cabernet Franc, Cayuga White, Chambourcin, Chancellor, Chardonel, Chardonnay, Gruner Veltliner, Marquette, Merlot, Noiret, Pinot grigio, Pinot noir, Pinotage, Riesling, Sauvignon blanc, Seyval blanc, and Traminette, Vignoles, Vidal blanc, and Zweigelt. If you have harvest updates you wish to be included in this report, please email them to [email protected].

The data in this report is possible due to the funding and support of the Pennsylvania Wine Marketing and Research Program. The authors and collaborators are grateful for the support.