Yeast nutrient is required to improve yeast health and ensure a good, vigorous and complete fermentation.
It is recommended to use yeast nutrient in all wine fermentations as it is often the only source of nitrogen in fruit wine musts and fruit juices. Yeast nutrient introduces nitrogen which is required to enable yeast cell reproduction during the growth phase and is essential for the wine quality by aiding the yeast in synthesising higher alcohols and esters.
In fermentations with a lack of nitrogen, yeast growth and the speed of fermentation are limited causing a slow or sluggish fermentation or even incomplete fermentation of all available sugars.
Yeast nutrient is added prior to fermentation by stirring into the wine must or beer wort.
For full bodied wines, a typical dose of yeast nutrient is around half a teaspoon per gallon, for lighter bodied wines 1 tsp is required per gallon. Maximum dosage is 1.5tsp per gallon of wine.