Monitoring small-scale alcoholic fermentations using a portable FTIR-ATR spectrometer and multivariate analysis

Nowadays, winemaking is dealing with great challenges, notably climate change, disease resistance and low pesticide inputs, desire for more sustainable agricultural productions and permanent changing of consumer preference.

In order to attenuate the effects of climate change on the ability to cultivate quality wine grape vines in Australia, it is essential to adapt to the projected less favourable Australian climate scenarios. One response may be to convert a portion of the current grapevine plantings to those varieties that demand less water and can tolerate increased heat. This investigation aimed to (i) generate sensory profiles and (ii) obtain knowledge about Australian wine consumers’ preferences and opinions of Australian wines made from potentially drought tolerant, white wine grape varieties not traditionally cultivated in Australia. A Rate-All-That-Apply (RATA) sensory panel (n = 49) generated sensory profiles of 44 commercial white wines made from 7 different white grape varieties (Arinto, Fiano, Garganega, Greco, Verdejo, Verdelho and Vermentino), plus two benchmark examples each of an Australian Riesling, Pinot Gris and Chardonnay wine.

Climate change is increasing the frequency of water deficit in many grape-growing regions. Grapevine varieties differ in their stomatal behavior during water deficit, and their ability to regulate water potential under dry soil conditions is commonly differentiated using the concept of isohydricity. It remains unclear whether stomatal behavior, water potential regulation, and the resulting degree of isohydricity has a relationship with changes to fruit growth during water deficit. This study was conducted on four varieties (`Cabernet Franc`, `Semillon`, `Grenache`, and `Riesling`) subjected to both short-term, severe water deficit and long-term, moderate water deficit applied at both pre- and post-veraison.

AIM: Agiorgitiko (Vitis vinifera L. cv.) is the most cultivated red grapewine variety in Greece1 located mainly in Nemea region, the largest PDO zone in Greece2. Although Agiorgitiko is considered as one of the most interesting red grape varieties, not only in Greece3, but also at international level4,5, however, there is a lack of knowledge

Spatial variability of vine productivity in winegrapes is important to characterise as both yield and quality are relevant for the production of different wine styles and products. The objectives were to understand how patterns of variability of Cabernet Sauvignon fruit composition changed over time and space, how these patterns could be characterised with indirect measurements, and how spatial patterns of the variation in fruit compositional attributes can aid in improving management. Prior to the 2017 vintage, 125 data vines were distributed across each of four vineyards in the Lodi American Viticultural Area (AVA) of California. Each data vine was sampled at commercial harvest in 2017, 2018, and 2019. Yield components and fruit composition were measured at harvest for each data vine, and maps of yield and fruit composition were produced for eight ‘objective measures of fruit quality’: total anthocyanins, polymeric tannins, quercetin glycosides, malic acid, yeast assimilable nitrogen, β-damascenone, C6 alcohols and aldehydes, and 3-isobutyl-2-methoxypyrazine. Patterns of variation in anthocyanins and phenolic compounds were found to be most stable over time. Given this relative stability, management decisions focused on fruit quality could be based on zonal descriptions of anthocyanins or phenolics to increase profitability in some vineyards. In each vineyard, dormant season pruning weights and soil cores were collected at each location, elevation and soil apparent electrical conductivity surveys were completed, and remotely sensed imagery was captured by fixed wing aircraft and two satellite platforms at major phenological stages. The data collected were used to develop relationships among biophysical data, soil, imagery, and fruit composition. The standardised and aggregated samples from four vineyards over three seasons were included in the estimation of ‘common variograms’ to assess how this technique could aid growers in producing geostatistically rigorous maps of fruit composition variability without cumbersome, single season sampling efforts.