Yeast Starter? Why does the manufacturer recommend just pitching one vial or pouch but must homebrewers recommend using a starter? I understand the manufacturer recommends starters with lagers and high gravity beers but the others they say The Activator is designed to deliver professional pitch rates (6 million cells/ ml.) when directly added to 5 gallons of wort. ( <1.060 at 70 degrees). However, if a package is slow to swell, suspected of being mishandled, or if the date is approaching the six month shelf life it is a good idea to build the culture up with a starter. High gravity or low temperature fermentations require higher pitch rates. This can be achieved with inoculating with additional packages or making a starter.