Non Saccharomyces wine yeasts: emerging trends and challenges in winemaking

Table grapes (Vitis labrusca and hybrids) are widely cultivated in Brazil [1] due to the climate, their resistance to disease and the way they are consumed and commercialized, either in-natura or for processing, producing whole juices, jams and table wines.

The Institut Français De La Vigne Et Du Vin (IFV) is conducting many experiments on innovative winegrowing practices, which are emerging in companies in the sector, or which are still at the R&D stage for agricultural suppliers. The purpose of these practices may be to reduce environmental impact, to adapt vineyards to climate change, or to achieve other technical, economic or social aims. Whatever the objective, it is necessary to verify the relevance of these new practices, and in particular their environmental relevance, i.e. That at the very least, the changes in practices do not increase the environmental impact of the technical itineraries.

Anthocyanins and phenolic compounds play a crucial role in winemaking, contributing to the profile, flavor, color, texture, and stability of wine. Grape clusters, specifically Vitis vinifera L. cv. Grenache, were handpicked from a commercial vineyard sited in Tudelilla, La Rioja, Spain (42°18′ 52.26″, Long. -2°7′ 59.15″, Alt. 582 m) on five distinct dates from veraison to harvest during the 2015 season. Non-contact spectral measurements were conducted on intact grape berries using a VIS-NIR spectrometer operating in the 570 – 1000 nm spectral range under controlled laboratory conditions, positioned at a distance of 25 cm from the berries. The quantification of 16 anthocyanins and phenols in 120 grape clusters was performed using HPLC, established as the reference method for validating the spectral tool.

The fortress of the Herodium, built towards the end of the first century BCE/ante Cristo, on the orders of Herod the Great, Roman client king of Judea, attests the expansion of Roman influence in the eastern Mediterranean. During archaeological excavations of the Herodium in 2017[1], a winery was discovered on the ground floor of the palace, with an assortment of clay vessels in situ, including large dolia – clay fermentation vessels each capable of fermenting up to 300-400 L of wine. Thanks to the recent progresses in the field of paleogenomics[2], we could analyse the organic material consistent with grape pomace at the bottom of these vessels, by extracting and sequencing the DNA using shotgun metagenomics and targeted capture, aiming for enrichment of DNA from fermentation associated microbes.

Grape flavour management in the vineyard requires knowledge of the derivation of individual flavour and aroma characteristics and the effects that different concentrations and interactions between these compounds have on flavour potential.