Lallemand Fermaid® AT is a blended complex yeast nutrient developed for low to moderate YAN conditions, which supplies a well balanced mix of organic nitrogen (wine yeast derived), inorganic nitrogen (DAP) and the vitamin thiamine.
The nitrogen content of Fermaid® AT is composed of 50% yeast derived organic nitrogen (amino acids and peptides) and inorganic (NH4+).
Organic nitrogen is assimilated more gradually than inorganic nitrogen. Different amino acids are taken up at different rates. Once inside the cell the alpha amino acids are integrated directly into proteins, degraded into ammonium (NH4 +), or used to produce fruit driven esters.
The NH4 + component is involved in biomass production of yeast cells. Reaching critical biomass is essential for successful fermentation.
The addition of thiamine to this complex nutrient allows for an improvement in the assimilation of both nitrogen sources and reduces the risk of off flavour production. Fermaid® AT contains the maximum permissible level of thiamine as stipulated by the OIV / EU. This preparation is designed to assist wine yeast in the latter half of alcoholic fermentation (AF). When Fermaid® AT is used in place of a DAP-only nutrient strategy, significant improvements in the sensory profiles of the wines are also evident. Fruit driven esters and a reduction in sulphidic characters can be achieved.
Re-suspend Lallemand Fermaid® AT in 10x its weight in water. Ensure it is well dispersed with no lumps, then add immediately to the tank.
Dose Rate of Fermaid® AT: Fermaid® AT is recommended for low YAN conditions.
A 30g/hL (300 ppm) dose of Fermaid® AT provides 36 mg/L of actual YAN.
For moderate to high YANs Lallemand recommends to use the product Fermaid® O.
Circumstances such as fruit quality, variety, winemaking practice, must parameters, yeast nutrient demand and cellar conditions are infinitely variable and impact on yeast performance.
- Store in a cool (below 25⁰C) and dry environment away from direct sunlight and strong odours.
- Shelf life at the recommended storage conditions is 4 years from date of production.