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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Comparing protocols for thiol production in Sauvignon Blanc (Scottlabs)(2018)

Veritas Vineyards and Winery, Emily Pelton

Thiols have become a defining characteristic of aromatic Sauvignon Blanc wines. Enological companies have developed specialized products to increase thiol production during fermentation and protection during aging. In this study, the standard protocol used at Veritas for production of Sauvignon Blanc is compared to the protocol recommended by Scottlabs. General wine chemistry was the same for both treatments. Wines were distinguished as different in a triangle test, with the Veritas protocol scoring higher in thiol intensity. Concentration of thiols and select esters were higher in the Veritas protocol wine.

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Reducing Green Character with Yeast Strains (Enartis) (2017)

This study examines the impact of different yeast strains on green character in Cabernet Franc. Cabernet Franc grapes were harvested and processed on the same day into 3 separate T Bins. Each T Bin received 25ppm sulfur dioxide and were then inoculated with either CSM (ScottLabs), D254 (ScottLabs), or D20 (Enartis). D20 yeast may reduce green character through higher fermentation temperatures blowing off pyrazine (Enartis 2018), therefore this T bin was fermented in the sun. CSM was chosen because it is also marketed as being able to reduce green character (Scott Laboratories 2018), but since it did not specify a higher fermentation temperature, this treatment was not fermented in the sun. Each T Bin was punched down twice per day and pressed on the same day for 9 days of maceration. All other treatments between wines were identical. All yeast strains had similar fermentation kinetics, with D20 perhaps being slightly warmer. Wine chemistry was similar between treatments, except that IBMP was slightly lower in the D20 yeast treatment. There were no strong trends for the descriptors used in this study. There was a slight trend for the CSM wine to have higher Fruit Intensity, and for the CSM and D20 wines to have higher Astringency. There was a slight preference for the D254 wine.

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Using Yeast to Improve Color and Aroma Extraction from Skins (in Collaboration with 2B) (2017)

This study examines the impact of Rubino Extra (2B), BM45 (ScottLabs), and Alchemy III (Anchor) on the phenolic and aroma characteristics of Cabernet Franc wines. The goal was to see if the Rubino Extra yeast could enhance anthocyanin and aroma extraction from the grapes, relative to other yeast strains. Grapes were harvested on the same day and processed into 3 separate T Bins. Each of the three T Bins were inoculated with one of the three yeasts. All other treatments between wines were identical. The BM45 trial fermented slowest, and Rubino Extra trial fermented fastest. Lactic acid was higher in the wine produced with BM45. Color intensity varied among yeasts. Anthocyanins were higher in the Alchemy 3 trial, and lower in the Rubino Extra trial. Overall, not many trends were seen between these wines. The Rubino Extra yeast tended to produce wines with slightly lower Overall Aromatic Intensity and Fruit Intensity. The Alchemy 3 and BM45 yeasts were fairly similar, except that BM45 was perhaps more in-between the Rubino Extra and the Alchemy 3 yeast. The Alchemy 3 yeast appeared to produce a distinctive floral or fruity quality. Preference trends reversed between tastings, and as such it is unclear which yeast strain was the most preferred.

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Enhancing Color Stability of Norton with Different Enological Fermentation Tannin (2017)

This study examines the impact of adding different kinds of exogenous tannin prior to fermentation in Norton grape must. Norton grapes were harvested on the same day and destemmed into four T bins. The T bins then received the following treatments: 1) No tannin addition (control), 2) Tan Color (Enartis) addition at 180g/ton followed by Pro Tinto addition (150g/ton) partway through fermentation (mostly condensed tannins), 3) FT Rouge (ScottLabs) addition at 60g/hL (hydrolysable tannin), and 4) a series of BSG product additions: UVA V-Tan at 30g/hL, Premium Limousin at 15g/hL, and Premium Color at 15g/hL (mix of condensed and hydrolysable tannins). All other treatments between wines were equal. After approximately two weeks, wine was pressed off. The BSG wine and the FT Rouge wine had slightly slower fermentations. Wines had slightly differing alcohol contents (slightly higher when using condensed tannin, and slightly lower when using hydrolysable tannin), but otherwise no major chemistry differences were seen. No color differences can be seen. The addition of these products may have slightly lowered caftaric acid and increased epicatechin and gallic acid, and these increases were more correlated to products containing condensed tannin. No major tannin or anthocyanin differences could be seen. For the descriptive analysis, there were no strong trends for the descriptors used in this study. There were slight trends for the control to have lower Fruit Intensity, Astringency, and Body. The wines made with BSG products tended to have higher Fruit Intensity, Overall Aromatic Intensity (along with FT Rouge in this regard), Bitterness, Astringency, and Body. The Pro Tinto/Tan Color and FT Rouge treatments were relatively similar and often fell in-between the Control and BSG products, except for FT Rouge with Overall Aromatic Intensity (where it was higher) and for Pro Tinto/Tan Color with Herbaceous/Green quality. In general, there was a preference for the wine produced with BSG products; however, judges thought that the wines were all fairly similar. In the future, more studies should be performed with these products on different grape varieties.

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The Effect of LalVigne Mature Foliar Spray on the South Side of Merlot Vines (2016)

This study examines the impact of LalVigne Mature Foliar Spray (ScottLabs) on ripeness and the chemical and sensory qualities of the South side of Merlot vines planted East-West. Every other row of a block of Merlot was sprayed at 5% veraison and 10 days later following the LalVigne spray protocol with a tunnel recycle sprayer, allowing for a treatment of sprayed Merlot and a treatment of unsprayed Merlot. Both treatments were harvested only from the South side of the vine (afternoon side) and processed identically and on the same day, but kept separate. All other treatments between projects were identical. The LalVigne spray slightly decreased tannins and anthocyanins in the grape berries. Caffeic acid was higher in wine from grapes treated with LalVigne. Tannin was also increased in wine from grapes sprayed with LalVigne, but anthocyanins were decreased. Triangle sensory testing revealed no significant differences between wines, and there was no strong preference for either wine. The sprayed wines tended to exhibit greater Fruit Intensity, but this was not a strong tendency.

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The Effect of LalVigne Mature Foliar Spray on the North Side of Merlot Vines (2016)

This study examines the impact of LalVigne Mature Foliar Spray (ScottLabs) on ripeness and the chemical and sensory qualities of the North side of Merlot vines planted East-West. Every other row of a block of Merlot was sprayed at 5% veraison and 10 days later following the LalVigne spray protocol with a tunnel recycle sprayer, allowing for a treatment of sprayed Merlot and a treatment of unsprayed Merlot. Both treatments were harvested only from the North side of the vine (morning side) and processed identically and on the same day, but kept separate. All other treatments between projects were identical. The LalVigne spray slightly increased tannins and anthocyanins in the grape berries, but lowered cluster weight (although not berry weight). Anthocyanins were decreased in the wine from grapes treated with the LalVigne spray. Triangle sensory testing found significant differences in the wines (p<0.05), although there was not much of a preference for one wine over the other. No major descriptive sensory trends can be seen.

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The Effect of LalVigne Foliar Spray on Cabernet Franc (2016)

This study examines the impact of LalVigne Foliar Spray (ScottLabs) on ripeness and the chemical and sensory qualities of Cabernet Franc. Every other row of a block of Cabernet Franc was sprayed at 5% veraison and 10 days later following the LalVigne spray protocol with a tunnel recycle sprayer, allowing for a treatment of sprayed Cabernet Franc and a treatment of unsprayed Cabernet Franc. Both treatments were harvested and processed identically and on the same day, but kept separate. All other treatments between projects were identical. The LalVigne spray slightly increased phenolics in the grape berries, but lowered cluster weight (although not berry weight). The LalVigne spray also increased YAN in juice. No chemical or phenolic parameters were very different in the wine. For the triangle test, of 20 people who answered, 12 people chose the correct wine (60%), showing a statistically significant difference between wines (p<0.05). These wines were voted to have an average degree difference of 4.2 (out of 10) among those who correctly identified it, suggesting that the wines were moderately different. In general, people who answered correctly had no preference for one treatment over another. There were no strong trends with regard to the descriptors used in this study.

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Effects of Adding Hydrolyzable vs Condensed Tannin during Red Wine Fermentation (2016)

This study examines the impact of adding different sources of exogenous tannin to fermenters during Merlot processing. The treatments were set up as follows: 1) Control, 2) FT Rouge (ScottLabs) at 30g/hL, 3) FT Rouge (ScottLabs) at 50g/hL, 4) Tanéthyl Effe (AEB) at 10g/hL, and 5) Oenotan Selection (Esvin) at 10g/hL. All treatments were the same, except that the treatment with FT Rouge at 50g/hL was inoculated with a different yeast from the rest. This wine was therefore not tasted at sensory sessions. No major wine differences could be seen between treatments. The tannin varied with their effect on color intensity: some increased intensity slightly whereas others slightly decreased it. Anthocyanin, in general, was slightly lowered by tannin addition. Tannin content was relatively unaffected, except for FT Rouge 50, which experienced a large increase in tannin. The differences from FT Rouge 50, however, may have been due to the yeast strain used, and does not indicate necessarily that the increase in tannin addition had the effects. Overall, no major preferences could be seen for any treatment, except that the Tan Ethyl Effe was often least preferred. There may have been large changes in wine sensory qualities in bottle over time, as the wines seemed to taste different at the different tastings. This could confound any attempt to compare wines across tastings. This study suggests that exogenous tannin can have impacts on final wine chemistry and sensory qualities, and this may be largely impacted by yeast strain selection as well. In the future, more studies examining the combined impact of exogenous tannin addition with yeast strain selection should be performed.

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H2S Production by Different Low-H2S Producing Yeast Strains (2016)

This study examines the effect of different low H2S-producing yeast strains on the sensory attributes of Cabernet Franc and Cabernet Sauvignon Rosé. The grapes were harvested on the same day, pressed together, and after settling was racked into four different 484L puncheons (2006 Hungarian oak from the same cooper). The barrels were inoculated with the following yeasts: Rhône 4600 (ScottLabs), Allegro (Phyterra), Sensy (ScottLabs), and Fermol Elegance (AEB). Rhône 4600 is not marketed as a low H2S-producing yeast strain and was intended to act as a soft control. The strains showed similar fermentation kinetics except for Rhône 4600, which was markedly slower. Additionally, the wine produced by Rhône 4600 had a higher alcohol content and higher total SO2, possibly from yeast production. The sulfide contents of the wines, however, were essentially indistinguishable. No strong trends were found with the descriptors used for this study. Rhône 4600 tended to show higher Fruit Intensity and Overall Aromatic Intensity. Many of these wines were perceived as slightly reduced. In general, people tended to prefer wines produced with Rhône 4600 and Allegro yeasts.

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ScottLabs IONYS WF Yeast Trial on Chardonnay (2016)

This study examines the impact of IONYSWF yeast (Lallemand) on Chardonnay wine when compared to fermentation with CY3079. Chardonnay juice was settled and split into separate barrels, inoculated with either CY3079 or IONYSWF. Although the IONYSWF fermentation proceeded much slower, not many chemical differences could be seen between the different yeast strains, except that the pH and TA of the IONYSWF – fermented wine was slightly higher. The lower level of free sulfur dioxide in CY3079 suggests a slightly higher production of sulfur dioxide-binding compounds. These results suggest that people are able to tell a difference between Chardonnay wine produced with IONYSWF yeast and wine produced from CY3079. People often preferred wine produced with IONYSWF yeast, likely due to its tendency to enhance Fruit Intensity, Overall Aromatic Intensity, Depth of Flavor, and Body. Although the yeast is marketed to increase acidity, this was not observed in this study. This yeast shows promise with regard to aromatic development in Chardonnay, but more studies are needed to confirm this.

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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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The Effect of LalVigne Foliar Spray on Chambourcin (2016)

This study examines the impact that LalVigne Foliar Spray (ScottLabs) has on the ripeness of Chambourcin grapes. Lalvigne was sprayed at 5% veraison and then 7-9 days later on a 2 acre parcel of Chambourcin at the recommended rate. Control and treatment grapes from the same block were harvested and processed on the same day, fermented separately as 1.5 ton lots in T Bins, and all other treatments between fermentations were kept the same. A third treatment was also added, were 75 pounds of Tannat skins were added to LalVigne-treated grapes at the beginning of fermentation. Although ripening kinetics between each treatment were similar (data not shown), anecdotally, the sprayed berries exhibited more color development. Juice from LalVigne-treated grapes exhibited higher nitrogen numbers (except lower ammonia). Wine produced with Tannat skins added had lower alcohol and pH (58% increase in proton concentration). In general, grapes treated with LalVigne showed increased color intensity and increased amounts of phenolic compounds. The sprayed grapes showed a large increase in Malvidin glucoside but a slightly lower count of monomeric and total anthocyanins. Tannat skins added to the LalVigne sprayed wine showed a smaller increase in color intensity, a larger increase in catechin, epicatechin, gallic acid, and tannin, and a decrease in anthocyanin content. For the triangle test, of 21 people who answered, 9 people chose the correct wine (43%), suggesting the wines were not significantly different. In general, people who answered correctly had a slight preference for the sprayed wine, but this preference was very weak. Descriptive analysis did not show many trends between wines. The control tended to have slightly lower Overall Aromatic Intensity to the sprayed wines, and the wine with Tannat skins seemed to have higher Fruit Intensity. The LalVigne spray wines tended to have slightly higher Herbaceous/Green scores, except for the wine with Tannat added.

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Yeast Nutrient Comparison in Chardonnay (2015)

The effects of the yeast nutrients Go Ferm, Fermaid O, and Fermoplus DAP Free on fermentation kinetics, wine chemistry, wine microbiology, and wine sensory attributes, were compared .  Go Ferm resulted in the most rapid fermentation.  Not much chemical differences were observed.  Most people preferred the wine made with Fermoplus DAP Free.

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Anchor and ScottLabs Yeast Comparison in Merlot (2014)

ScottLabs EC 1118 PDM, ScottLabs CRVP, Anchor NT50, and Anchor NT202 yeast strains were compared for their effect on pH, ethanol and volatile acidity production in 2014 Merlot.  Fermentation kinetics were also compared.  CRVP exhibited the fastest fermentation kinetics but produced the highest volatile acidity. EC 1118 PDM produced the highest ethanol and lowest volatile acidity.

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Fermentation Tannins in Chardonnay (2015)

Chardonnay fermented with either Tan Citrus (Enartis) or FT Blanc (ScottLabs) were compared for chemical and sensory characteristics.  No significant differences were found for both chemical and sensory attributes, and there was no real preference between wines.  However, Tan Citrus should be put into a wine fermenting with a B-glycosidic yeast strain for full effect, and the yeast strain used in this study was not identified.

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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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The Effect of Different Products on Merlot Color Stability (2014)

One Merlot wine was made using a mixture of ScottLabs Color Pro, Tannin VR Supra (Laffort), and French oak chips.  The other wine was made with a mixture of Zym Color Plus (Enartis), Tan Fermcolor (Enartis), and Tan Color (Enartis).  Both experimental wines were meant to mimic similar enzymatic and tannin additions.  There were no chemical differences between the wines, and sensory testing was not performed in this project.  No resources to measure color or phenolic content were available for this project.

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LalVigne Mature Foliar Spray with Virginia Merlot (2014)

This study examined the chemical and sensory effects of LalVigne Mature Foliar Spray on finished Merlot wine.  There were no chemical differences in the grapes that were harvested in this study; however there were significant sensory differences between the final wines.  People tended to prefer the wine produced without the spray.

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