Originally Posted by 944play
I would make a small batch (3-4 gallons) of helles or Vienna lager with 2 vials direct-pitched and rinse the cake. If you make a starter, it will have to be at least a couple gallons anyway. You'll need about a cup of thick, healthy yeast for a doppelbock.
From what Brewsmith and MrMalty say you would need to pitch 2 vials of yeast and using a stir plate
need about a 3 liter starter. The size of your starter goes up exponential if you do a lesser method of a starter ie.. simple starter or shaken every few hours!
If you don't have a stirplate I'd go with what 944play recommends!