It's tough to go a full 2L in a2L flask because you add the DME to the 2L volume which pushes you over the limits for a 2L flask. If you're not using a stirplate then ANY container can be used for a starter as long as you can sanitize it....go buy a gallon of apple juice in a glass jar and you're set...drink or dump the AJ....or buy 4 and start a batch of apfelwine and you'll have 4 starter vessels of 1 gallon each!!
Something is always fermenting....
"It's Bahl Hornin'"
Kegged: Sour Saison, Pale Ale, Aggie Ale, Firestone DBA, De Koninck Blonde
Bottled: Belgian Quad (Grand Reserve), Derangement (Belgian Dark Strong)
On Deck: Pliny the Younger