2025 Post-Veraison in Pennsylvania - October 14

Report #7, Samples taken the week of October 6, 2025

This is the seventh 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. We thank 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 and Fayette Counties (Cabernet Franc grapes were not received from Lehigh County); Chambourcin has been harvested in Chester County; Chardonnay has been harvested in Lehigh and Snyder Counties; Riesling has been harvested in Chester and Fayette Counties; and Vidal blanc has been harvested in Snyder County.

Primary fruit composition: soluble solids (Brix), pH, and titratable acidity.

Cabernet Franc samples from the week of October 6 were only collected from Erie and Snyder Counties, as Cabernet Franc was harvested at other locations before samples could be sent in for this report. Samples collected the week of October 6 indicated that fruit maturity was more advanced in Snyder County relative to Erie County; however, the trends suggest that maturation advanced towards harvest in both locations. (Figure 1). Compared to the previous week's fruit composition in both counties, Brix levels increased by a range of 4.1 (Erie) to 4.6 (Snyder); pH increased by a range of 0.21 (Erie) to 0.50 (Snyder); and titratable acidity decreased by a range of 0.60 g/L (Erie) to 5.25 g/L (Snyder).

Note - the three counties that participated/are participating in PVIP in 2024 and 2025 are Erie, Fayette, and Snyder Counties. Average Cabernet Franc fruit composition from Erie, Fayette, and Snyder Counties are used to compare last year's and this year's editions of PVIP (except for this report, which averages across Erie and Snyder Counties since Cabernet Franc was harvested in Fayette Erie County). Relative to the sixth week's report from 2024 (samples collected during the week of October 7), last week's samples showed: higher average Brix (+1.8), comparable pH, and lower average TA (-5.50 g/L). These differences suggest that Cabernet franc primary fruit composition in 2025 is relatively more mature and advanced compared to the same period in 2024. This contrasts with last week's report, which indicated that 2025 trends were "delayed relative to 2024," which may have been due to the onset of rain in some locations that week.

Chambourcin was most mature in Snyder, followed by Fayette, and then Erie (Table 1). Relative to samples from last week, Brix increased by a range of 0.9 (Fayette County) to 6.2 (Erie County). While Chambourcin pH remained the same in Erie, it moderately increased in Fayette County and dramatically decreased in Snyder County. Relative to last week's report, Chambourcin TA decreased only in Erie (-0.45 g/L) but increased in Fayette County (+0.60 g/L) and Snyder County (+ 1.20 g/L). The only Riesling and Vidal blanc samples received last week were from Erie County, where the only indicator of maturity advancement was an increase in Brix (+1.6 and +2.1, respectively), as pH decreased (-0.24 in Riesling) or didn't change (for Vidal blanc) and TA increased (+2.55 g/L and +2.40 g/L, respectively).

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 viticulture@psu.edu.

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.