The Effect of Bactiless on Microbial Stability in Petit Verdot (2016)

This study examines the impact of Bactiless (ScottLabs) on the chemical, microbial, and sensory profiles of two Petit Verdot wines, one of which was not tasted. Petit Verdot wine was racked into two separate barrels for each wine, and allowed to undergo natural malolactic conversion. After malolactic conversion, one barrel from each wine received a sulfur dioxide addition of 6.6g/hL, whereas the other barrel from each wine received 4.4g/hL sulfur dioxide and 50g/hL Bactiless. After 10 days both barrels were racked and returned. Bactiless seemed to lower cell counts for Pediococcus sp, acetic acid bacteria, and Oenococcus oeni. The results varied between wines, however. Other microbes were not strongly impacted by the treatment, but in many cases the cell count may have been too low to be impacted by the treatment. The wines were not significantly different from triangle testing. No major descriptive trends could be seen in this study.

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Hyperoxidation Fining Trials of Petit Manseng (2016)

This study examines the effect of adding fining agents to hyperoxidized Petit Manseng juice on the sensory and phenolic characteristics of Petit Manseng. After reducing the temperature to 10-12°C, Petit Manseng juice was hyperoxidized by pumping four volumes of juice over a sump screen, taking about 10 minutes. After this process, juice was very brown and then sulfur dioxide was added at 50ppm. Juice was then split into two vessels, one of which was fined with casein, PVPP, and bentonite to remove solids and phenolic compounds. All other treatments between juices and wines were identical. Overall, no major chemical, color, or phenolic differences were observed between the wines, suggesting that fining juice after hyperoxidation does not do much to alter the color and phenolic properties of the wine. Triangle testing suggests that the wines were significantly different from each other (p<0.001), likely due to a difference in turbidity. No preferences could be seen for one wine over the other. The fined wine had a slight tendency for lower Tropical Fruit and increased Bitterness/Astringency.

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