## 4 Conclusions  
In Chardonnay, the concentration differences of total Cu and free Cu remained significant until bottle aging for 15 months. However, in the Shiraz wines, there was no significant difference for total Cu, except for free Cu at post-fermentation. Cu treatments increased the H\({}_{2}\)S concentration in Chardonnay, and SO\({}_{2}\) must additions resulted in elevated H\({}_{2}\)S concentrations in the Shiraz wines. While none of the treatments were found to have an effect on H\({}_{2}\)S concentrations at bottling, the impacts of Cu treatment remerged after 15 months of aging in the Chardonnay wines, regardless of the bentonite treatment. Cu treatments in the juice/must repressed MeSH concentrations in all the wines after fermentation, regardless of variety. However, the differences were most evident in Chardonnay after fermentation and became less significant after 15 months of bottle aging. In Shiraz, differences in MeSH levels decreased at bottling, but remerged after bottle aging. Both of the Cu and SO\({}_{2}\) additions increased the concentrations of hexanal, 3-methylbutanal, and phenylacetaldehyde after fermentation, showed no influences at the pre-bottling stage, and decreased their concentrations after bottle aging in Shiraz wines. In Chardonnay, only 3-methylbutanal and phenylacetaldehyde were impacted by Cu and SO\({}_{2}\) treatments, and importantly, the treatment effects remained significant throughout the wine production and the bottle aging process. Bentonite treatments increased the concentrations of most measured aldehydes, and this effect largely remained throughout bottle aging. Hexanal and methional showed more subtle differences due to Cu treatments after the cold stabilization, and no differences were evident after bottle aging. This study shows that the SO\({}_{2}\) and Cu composition of juice/must can have long-term implications for wine composition, and in particular it can impact wine compounds that are linked to oxidative and reductive wine aroma. The following are available online at [[http://www.mdpi.com/2306-5710/5/4/70/s1](http://www.mdpi.com/2306-5710/5/4/70/s1)]([http://www.mdpi.com/2306-5710/5/4/70/s1](http://www.mdpi.com/2306-5710/5/4/70/s1)). Table S1. Analytical standards used for the chemical analysis; Table S2. Concentrations of Fe (mg/L) in Chardonnay wines, and concentrations (\(\mu\)g/L) of analysed LMWSCs and volatile aldehyde compounds in Chardonnay and Shiraz wines during production and bottle aging process; Table S3. Color parameters and protein concentrations (Chardonnay only) of Chardonnay and Shiraz wines at PB; Table S4. Concentrations (ug/L) of analyzed esters, C6 compounds, terpen, and C13 compounds in Chardonnay and Shiraz wines during production and the bottle aging process; Figure S1. Concentrations of benzaldehyde in Chardonnay and Shiraz wines during production and the bottle aging process. The X-axis of the figure represented sampling time points: J/M, juice/must; PAF, post-alcoholic fermentation; PCold, post-cold stabilization; PB, pre-bottling; 15 Mo, 15 months after bottle aging. (A) Benzaldehyde in Chardonnay wines; (B) benzaldehyde in Shiraz wines. Conceptualization, X.Z., N.K., and A.C.C. ; methodology, X.Z. and J.W.B. ; investigation, X.Z., N.K., and A.C.C. ; resources, J.W.B. ; data curation, X.Z. and N.K. ; writing-original draft preparation, X.Z. ; writing-review and editing, X.Z., N.K., J.W.B. and A.C.C. ; visualization, X.Z. ; supervision, A.C.C. This research was funded by Charles Sturt University Postgraduate Research Scholarship and Wine Australia (AGW Ph1509). This work was conducted as part of a Ph.D. program at the National Wine and Grape Industry Centre (NWGIC) supported by a Charles Sturt University Postgraduate Research Scholarship and an International Tuition Payment scholarship. Further stipend and operating support was provided by Wine Australia (AGW Ph1509).