Wednesday evening, the Top10 Sauvignon blanc wines will be announced. The cream of the crop was carefully selected from the finest Sauvignon blanc wines in South Africa!

Now is the perfect time to recap on the 2017 winning wines before the newcomers take the spotlight! In case you missed the roadshows (and some seriously interesting discussions!) which took place in the past few months, here are links to download the information sheets on the respective wines:

 

2017 FNB SAUVIGNON BLANC TOP 10
Technical Data

Chemical Composition
Sensory Results

In terms of the wine styles, the wines ranged from tropical fruit bombs to greener styles, more mineral driven wines as well as wines with wood components. The contribution of 4MMPto some of these wines added the sought-after blackcurrant aroma and diversified the styles produced from this noble cultivar. Often a wine showed a combination of the above-mentioned aspects highlighting the potential complexity that can be crafted.

Diemersdal created a unique new world Sauvignon Blanc from frozen juice! The grape must was frozen soon after harvesting and was only thawed during the winter months after which fermentation was initiated. The astonishingly high level of volatile thiols (3MH and 3MHA, the compounds responsible for the tropical fruit aroma) found in this wine (see chemical composition) can be as a result of using the freeze-thaw process.

A study done in New Zealand also showed that freezing and thawing the juice can lead to increased amounts of volatile thiols in the corresponding wine. The explanation for this could be the increased leaching of precursors and enzymes into the grape must due to berry damage from ice crystal formation. Ice formation thus not only increases contact between reactants, but also concentrates the reactants in the available liquid thereby facilitating the reaction. The expense involved in using this freeze/thaw cycle may not be economical when processing large volumes of must, however, this technique could be applied in smaller batches to obtain larger diversity in wine styles.

The question of the aging potential of the winning wines was also a hot topic during the roadshows. It is well known that volatile thiols are subjective to oxidation and acid hydrolysis and a decrease in these compounds can be expected over time. For interest sake, Vinlab tested 10 wines for volatile thiols one year after the announcement of the top10. Interestingly, there were no large differences in 3MH concentrations after one year, however the concentration of 3MHA did, in most cases, decrease quite significantly.

3MHA can transform into 3MH over time and is also much more sensitive to oxidation compared to 3MH. For the best preservation of the volatile thiols sufficient sulphur dioxide concentrations should be present. Vinlab also tested the sulphur dioxide content after one year and results showed that the free and total SO2levels remained relatively stable which is a good indication of effective bottling procedures in place. This also suggests 3MHA underwent a natural degradation over time. The temperature at which the wines are stored will also have a pronounced effect on the volatile thiols, especially 3MHA. The tested wines were stored at room temperature for the 12 months which could have facilitated the degradation of 3MHA.

In future, SBIG would like to informally test the efficiency of low storage temperatures on the preservation of not only the volatile thiols, but the wine as a whole. The idea is simply to store a few bottles of the top10 wines at room temperature and a few at 4ºC, aiming to lock-in that top10 goodness!

adminWednesday evening, the Top10 Sauvignon blanc wines will be announced. The cream of the crop was carefully selected from the finest Sauvignon blanc wines in South Africa!