Microbiological characteristics :
-Killer (K2) factor neutral
-Fermentation speed : fast
-Lag phase : short
-Sugar to alcohol conversion : 16 g/1% alcohol
-Alcohol tolerance : high (up to 17%)
-Fermentation temperature range : 15 to 25°C
Enological properties :
-Low need for available nitrogen
- Important survival factor requirements (sterols and fatty acids)
- sensitive to copper (> 1 mg/l)
- Volatile acidity production: average (approximately 0.35 g/l eq H2SO4). More volatile acidity may be produced during the first three days of the alcoholic fermentation if the instructions and conditions of use are not respected.
- Reveal terpenes (Muscat, Muscadelle, Semillon) through its ß-glycosidase activities.
- Preserve the aromatic balance with dominating geraniol (rose) and linalol (orange flower, rose) characters.
- Good expression of certain aromatic thiols (grape varieties such as Sauvignon, Riesling…)
Winemaker’s notes :
Levuline ALS has an excellent fermentation potential allowing for a good implantation in the inoculated tanks. However, its growth requires an important amount of sterols. In order to optimize its qualities and limit its production of volatile acidity, it is ESSENTIAL to add a sufficient quantity of sterols and to follow the instructions for use described in this technical data sheet.
Moreover, it is necessary to:
- perform a pumping over towards the end of the growth phase (density of 1040)
- maintain turbidity level above 100-150 NTU as sediments are a source of sterols.
- add a complex activator (such as Helper or Milieu Total), which is a source of yeast sterols if SO2 is above 5 g/hl.
With aromatic grape varieties, maintain a temperature of 18°C during fermentation in order to better reveal the varietal aromas.
It is recommended to add Genesis Native, a source of yeast sterols, to the medium before adding Levuline ALS. Dilute the required amount of Genesis Native in 20
times its liquid weight (30 g/hl of the wine to beinoculated). Mix well. Add the yeasts and mix again. Rehydrate for 30 minutes.
After rehydration, prepare yeast regeneration: aerate the medium for 30 seconds for homogenization. After 30 minutes of regeneration, homogenize again before adding the preparation to the tank. When inoculating, the temperature difference between starter and must should not exceed 10°C.
Total duration for yeast preparation is one hour.
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