## 5 Concluding Remarks and Future Prospects  
Various scientific and wine technological developments have occurred in the wine industry to improve the varietal aroma and flavour profiles as well as the quality of wines. These advances have given rise to innovative wine styles being produced from the same grape varieties through either the direct manipulation of the grape berry before the winemaking process, or a combination of processes during wine production. However, the ability to manage the development of flavour compounds, i.e., varietal thiols, and their association with the sensory quality of wine using viticultural or oenological practices is yet to be demonstrated. The literature reported that a combination of these practices could influence varietal thiols and their precursors. Subsequently, most procedures demonstrated varied results, with the number of precursors in grapes not directly reflected in the varietal thiols quantified in the final wine. Therefore, specific vineyard and winemaking practices for increasing thiol and aroma compound concentrations in wines are still needed.  
Moreover, the cryogenic treatment of grapes as a pre-fermentation treatment could be a useful alternative based on cryogenic processing technologies already applied in the beverage industry. Previous studies demonstrated its potential for thiol management in Sauvignon blanc, with thiol precursors increasing by four times in frozen grapes stored at \(-20\)\({}^{\circ}\)C for two months compared to that found in frozen or fresh juices. Subsequently, studies using dry ice for the pre-fermentative cryomaceration of Sauvignon blanc grapes must also show an increase in 3-SH and 3-SHA concentrations in the resulting wine. However, it should be noted that although these new winemaking technologies greatly contribute to the increase in the extraction of aroma compounds, the grape variety used is still largely responsible for the aroma profile of the final wine due to differences in their skin cell layers and sizes. Moreover, there is a lack of information on the effect of these treatments on methoxypyrazines, which needs to be addressed as they are major compounds contributing to the varietal style of Sauvignon blanc and other wine grape varieties.  
Furthermore, it is recommended that future research applications combine ultrasound technology, microwave-assisted extraction, and pulsed electric field technology with cryogenic pre-treatment technologies to further improve the extraction of aroma compounds to produce innovative wine styles. These technologies could add value to the wine industry as they showed promise in the acceleration of aroma extraction from oak chips, for the reduction in microbiological populations, reducing SO2 usage, as well as the acceleration of aging on the lees. However, current studies are only being conducted on a small or laboratory scale and further optimisation on an industrial scale is needed to verify the reliability of results.  
Writing--review and editing, V.M.v.B.; visualization, V.M.v.B.; supervision, F.P.v.J. and J.v.W.; project administration, F.P.v.J.; funding acquisition, F.P.v.J. All authors have read and agreed to the published version of the manuscript.  
This research was funded by South Africa Wine grant number [P04000266].  
Thanks to the Agricultural Research Council (ARC), Infruite-Nietvoorbij for providing the infrastructure and financial support; the industry partner, i.e., South Africa Wine, for financial support; [PERSON] (Post-Harvest and Agro-processing Technologies Division, Agricultural Research Council Infruite-Nietvoorbij) for continuous technical support, mentorship, and motivation; [PERSON] (Basic Wine) for consultation services and technical support.  
The authors declare no conflicts of interest.