Certain yeast species belonging to the Pichia genus are known to form a distinctive film on grape must and wine. In a mixed-culture type fermentation, Pichia spp. (P. kluyveri in particular) are known to impart beneficial oenological attributes. In this study, we report on an easy isolation method of Pichia spp. from grape must by exploiting their film-forming capacity on media containing 10% ethanol. We isolated and identified two Pichia species, namely Pichia kudriavzevii and Pichia kluyveri, and subsequently co-inoculated them with Saccharomyces cerevisiae to ferment Gewürztraminer musts. Noteworthy differences included a significant increase in the 2-phenethyl acetate levels with the P. kluyveri co-fermentation and a general increase in ethyl esters with the P. kudriavzevii co-fermentation. Both Pichia co-inoculations yielded higher levels of glycerol in the final wines. Based on all the wine parameters we tested, the P. kluyveri strain that was isolated performed similarly to a commercial P. kluyveri strain.

Clonal evaluation of winegrapes in California has not been extensive. Early selection work by Alley (1977), Olmo (unpublished data) and Goheen (personal communication) resulted in the current collection

In northern cold climate conditions, chilling requirement fulfillment in dormant grapevine buds is slowed or stopped by subzero temperatures impacting the transcriptional processes needed to complete chilling requirement. Cabernet Franc and Reisling in Geneva, NY were used to determine the impact of natural oscillating temperatures on grapevine bud transcriptional activity during light and dark periods of a two-week period in January with fluctuating diurnal winter temperatures. Cabernet Franc and Reisling bud samples were collected at 32 time points during the natural vineyard temperature cycle at 6:00 (dark), 14:00 (light) and 18:00 (dark) hours) to monitor gene expression in consecutive freezing and non-freezing temperature oscillations. Genotype, light and dark, and temperature oscillations conditions were explored.

The wine sector is one of the most significant industries worldwide, with Spain being a leading country in wine production and export. A key factor in wine quality is its aroma, which is directly influenced by the volatile compounds present in the grape, with terpenes being among the most significant contributors.

The global non-alcoholic wine market is projected to grow from USD 2.7 billion in 2024 to USD 6.97 billion by 2034, driven by health awareness, lifestyle shifts, and religious factors [1-3]. Consequently, the removal of alcohol can significantly alter the key quality parameters of wine.