Winetech Technical Yearbook 2022

SHUTTERSTOCK

RESULTS Saccharomyces cerevisiae (control)

showed the juice had approximately 26°Brix/Balling and a pH of 3.9. Five different LT strains were used in this study (LT1, LT2, LT3, LT4 and LT5). Of the commercially available strains, LT2 has been identified as Laffort’s ZYMAFLORE ® OMEGA LT . 20 LT strains can ferment to about 10% v/v ethanol 21 and therefore require simultaneous or sequential addition of another co-starter to complete fermentation. In the current study, all LT strains’ performance was tested by doing a co-inoculation and a sequential inoculation with a Saccharomyces cerevisiae yeast strain. These fermentations and wines were compared to a treatment where the chosen Saccharomyces cerevisiae (SC) was used alone to ferment the juice, as well as an uninoculated treatment (UN). For the sensory evaluation, 47 experienced wine tasters were asked to evaluate the intensities of certain sensory attributes using a seven-point scale where 1 = extremely low, 4 = moderate intensity and 7 = extremely high. Assessors were also asked to indicate which attribute best described the wine acidity profile by selecting one or more of the following profiles: ‘flat/flabby’, ‘crisp/ fresh/bright’, ‘sour/tart’ and ‘harsh/acrid’.

Ethanol % v/v pH TA (g/L as tartaric acid)

Lactic acid (g/L)

16.5 3.86

5

0.4

• Resulted in high-alcohol and low acidity wines. • Sensory panel rated the wine as the least ‘acidic’.

• Sensory panel rated the wine high in ‘sweetness’, ‘hotness’ and ‘body’ (probably due to the lower acidity as these attributes did not correspond with the residual sugar levels). • High abundance of ethyl esters of medium-chain fatty acids, however, the compounds failed to enhance the fruity character of the wines. • Approximately 50% of the sensory panel described the wine as ‘flat/flabby’.

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WINETECH TECHNICAL YEARBOOK 2022