Fermax Yeast Nutrient is a premium nutrient contains diammonium phosphate, dipotassium phosphate, magnesium sulfate and autolyzed yeast. Great for all beer and winemaking. Use 1 tsp per gallon in last 10 minutes of boil. Yeast nutrient is critical for vigorous and complete fermentations that result in the greatest tasting beers or wines. The addition of yeast nutrient creates a healthier yeast population and improves fermentation behavior. A strong yeast population dramatically enhances the flavor and character of all beers and wines. Yeast nutrient does not contain yeast which must be added separately.