Yeast Nutrient - Beer (Wyeast)
Wyeast's yeast nutrient for beer is a blend of vitamins, minerals, inorganic nitrogen, organic nitrogen, zinc, phosphates and other trace elements that will benefit yeast growth and complete fermentation. Additional nutrients are most valuable during yeast propagation and sluggish or stuck fermentations. Supplementing with nutrients will reduce lag time, improve viability and provide consistent attenuation rates.
Use 1/2 tsp. per 5 gallons of wort with 10-15 minutes left in the boil.