American Wheat Yeast. Activator pack. 100 billion cells. A dry fermenting true top cropping yeast which produces a dry, slightly tart, crisp beer in American Hefeweisen style. Flocculation: low, apparent attenuation: 74-78%, 58-74 deg F. 125 ml XL packets contain 5 times the amount of yeast as a regular Wyeast package. There is enough yeast to pitch 5 gallons of wort without incubation or 15 gallons with incubation.