Terroir and precision viticulture: are they compatible?

REVINE is a 3 year European projected funded by PRIMA programme which proposes the adoption of regenerative agriculture practices with an innovative and original perspective, in order to improve the resilience of vineyards to climate change in the Mediterranean area. Regenerative agriculture ameliorates soil structure and microbial biodiversity that, in turn, leads to crop resilience against biotic and abiotic stressful factors. Moreover, enrichment of beneficial microbes in the rhizosphere, such as PGPR and PGPF, are known to trigger the plant immunity inducing the priming state.

AIM Aiming to explore the possibility of shortening red winemaking maceration times (1,2), this study presents the effect of the application of high-power ultrasounds to crushed grapes, at winery-scale, on the content of varietal volatile compounds (free and glycosidically-bound) in musts and on the overall aroma of wines.

Following anecdotal evidence of unwanted ‘tropical’ character in red wines resulting from vineyard interventions and a subsequent yeast trial observing higher ‘red fruit’ character correlated with higher thiol concentrations, the role of polyfunctional thiols in commercial Australian red wines was investigated.
First, trials into the known tropical thiol modulation technique of foliar applications of sulfur and urea were conducted in parallel on Chardonnay and Shiraz.1 The Chardonnay wines showed expected results with elevated concentrations of 3-sulfanylhexanol (3-SH) and 3-sulfanylhexyl acetate (3-SHA), whereas the Shiraz wines lacked 3-SHA. Furthermore, the Shiraz wines were described as ‘drain’ (known as ‘reductive’ aroma character) during sensory evaluation although they did not contain thiols traditionally associated with ‘reductive’ thiols (H2S, methanethiol etc.).

White wines are commonly stabilised by removing the heat unstable proteins through adsorption by bentonite, an effective but inefficient wine processing step. Alternative absorbents are thus sought and zirconium dioxide (zirconia) is recognised as a promising candidate.

This study evaluates the effect of microwave treatment in grape maceration on the content of free and glycosidically bound varietal compounds) of must and wine and on the overall aroma of wines produced in the presence and absence of SO2.