The effect of Stimula Sauv Blanc (Scottlabs) fermentation nutrients on Thiol Production in Sauvignon Blanc (2018)

Stinson Vineyards, Rachel Stinson Vrooman

Thiols have become a defining characteristic of aromatic Sauvignon Blanc wines. Enological companies have developed specialized nutrients to increase thiol production during fermentation. In this study, fermentation using Stimula Sauv Blanc, a yeast nutrient specialized for thiol production is  compared to fermentation using Fermaid O, a non-specialized yeast nutrient. Resulting wines had very similar general chemistry and thiol content. Triangle difference testing concluded the wines were different, however scores for thiol intensity were not significantly different between wines. Some fruity and floral esters were higher in the wine produced using Stimula Sauv Blanc.

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Summary Graph Stinson.jpg

The Effect of Juice Turbidity on Aroma Development of Sauvignon Blanc (2016)

This study compares the effects of fermenting Sauvignon Blanc juice at a low (50 NTU) or high turbidity (250 NTU). Juice from the same pick of Sauvignon Blanc was settled and racked into stainless steel barrels. Turbidity was adjusted by adding back fine lees to the juice. All other treatments between wines were the same. No major chemical differences could be found between juice or wine, except that the juice with higher turbidity had slightly higher YAN and its wine had slightly lower alcohol. High turbidity greatly increased 3-mercaptohexanol and 4-methyl-4-mercaptopentan-2-one, but decreased 3-mercaptohexylacetate. Triangle testing suggests that the wines were significantly different (p<0.001). No major preference could be seen for one wine over the other. No major trends could be found for the descriptors used in this study, despite the wines being found to be significantly different. There was a slight tendency for the High NTU wine to have more Varietal Character and Overall Aromatic Intensity, while having less Body.

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CY3079 and Vivace Yeast Trial in Chardonnay (2015)

Chardonnay wines produced with CY3079 and Vivace yeast strains were compared. Vivace yeast is marketed as a low hydrogen sulfide-producing yeast.  There were little chemical differences between the resulting wines, although significant sensory differences were discerned.  People tended to prefer the wine produced with CY3079.  No conclusions can be drawn about the efficacy of Vivace in producing low levels of hydrogen sulfide.

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Press Enzyme Comparison: Cinn-Free vs. Lafazym Press (2015)

The effect of press enzymes Cinn-Free (ScottLabs) and Lafazym Press (Laffort) on finished Sauvignon Blanc wine were compared.  There were no chemical differences between the wines except that the Lafazyme-treated juice had a slightly higher titratable acidity.  There were no significant sensory differences between the wines, but there seemed to be a slight preference for Lafazyme.  No yield comparisons were made.

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Concrete vs. Stainless Steel Aging with Sauvignon Blanc (2014)

This study compares the chemical and sensory effects of aging Sauvignon Blanc wine in concrete and stainless steel vessels.  Although there were no chemical differences between the wines, there were significant sensory differences between the wines.  This seems due in part to the stainless steel-aged wine being slightly oxidized, but there were reports of the concrete egg-aged wine having a creamier and fuller mouthfeel.

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Cold Soak vs. No Cold Soak with Merlot (2014)

Two different Merlot clones (181 and 343) were evaluated for chemical and sensory differences due to cold soaking.  Not much color difference was observed between wines that had undergone cold soak compared to controls.  However, significant sensory differences existed between wines, with most people preferring cold soaked wines.

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