I've gone up to 5 months with crushed grain in sealed bags without noticing any ill effects, however that was with an extract recipe.
Primary: Apfelwein w/ fructose, Apfelwein w/sucrose
Aging: Matt's Mega Cider, Raspberry wine, Unfiltered Apple Cider
Bottled: IPA, Hefeweizen, Magic Hat #9 clone, CCA, Apfelwein, Panty Dropping Apple Cider
Kegged: Belgian White PM, Orfy's Hob Goblin