### Sensory Evaluation of Wine Quality from Individual Variants  
In the sensory evaluation of the mature wine, without the influence of the variant, some results were in favour of the targeted oxygenation variant and some were neutral. This finding--that targeted oxygenation of the must does not have adverse effect on the wine sensory parameters--is considered a favourable result. Results from the sensory evaluation of the wines produced by reducing the technology or targeted must oxygenation are published in a previous study by [PERSON] et al. [29]. In summary, we observed the following differences: wines produced by the reductive method showed broad primary aromas of blossoming meadow, tropical fruit, linden blossom, and aromas of vanilla and green apple. The grassy, green, phenolic tones, which are a risk for the further maturation process of the wine, were disturbing. In the variant produced by the oxygenation method, the wines did not show grassy but spicy tones, which the commission assessed positively. Furthermore, the commission identified minerality (quartz), ripe apple, and varietal manifestation of ripe grapes as important descriptors. The results of the sensory evaluation with use of the 100-point test are shown in Figure 2.  
Unlike in red wines, the technology of white wine production has to take into account not only the positive antioxidant properties of the phenolic substances, but also their adverse effect on the oxidative and aging processes. It is necessary to naturally eliminate phenolic substances as the increased antioxidant content and high antioxidant activity do not affect the sensory profile of wine positively [40]. Influence of Targeted Must Oxygenation Technology on the Content of Volatile Phenolic Substances in Wine  
In both varieties and variants with targeted oxygenation, a statistically significant reduction in the content of undesirable 4-vinylguaiacol and 4-vinylphenol was achieved. The results are shown in Table 3. These substances are found in young wine in very low concentrations, usually in \(\mu\)g L\({}^{-1}\). The olfactory thresholds of the volatiles are very low. Therefore, the results obtained are considered to be very positive, in favour of the sensory attributes of wines produced by the targeted oxygenation of must. Other undesirable volatile phenolic substances that may be present in the wine are 4-ethylphenol and 4-ethylguaiacol. Their content was in all variants at a non-detectable level. For this reason, we did not include them in the evaluation. We compared the sums of the volatile phenolics in individual varieties in individual viteries in individual vintages in order to find out if the oxygenation contributed to the decrease in volatiles. Significant differences were found in all variants and vintages. A decline in the sum of the volatile phenolics ranged from 9.8 to 41.7%. In vintage 2015, we observed the highest decline in content of both volatile phenolics. 4-vinylguaiacol decreased in Welschriesling by 57.2% and 4-vinylphenol by 38.1% between the experimental variants. In Chardonnay, the decrease in phenolics ranged from 9.2 to 37.3% for 4-vinylguaiacol and from 7.2 to 29.1% for 4-vinylphenol. The findings are in agreement with those of [PERSON] et al. [41], in that the yeast _S. cerevisiae_ produces vinylphenols in alcoholic fermentation, but not ethylphenols. Ethylphenols are formed from hydroxycinnamic acids by the action of the microflora of _Brettanomyces/Dekera_ spp., _Pichia_ spp., _Toruslapora_ spp., and _Zygosaccharomyces_ spp., i.e., during long-term maturation and secondary contamination, especially in the case of red wines.