I've been using the same bucket of Starsan since September. I never quite trusted when people said it would last a long time, but then I ran out of Starsan and haven't bought a new bottle. So, I have forced myself to keep using what I've got. Haven't had any problems yet. Maybe after the holidays I'll get around to buying a new bottle of the stuff.
Fermenting - BBD Sour; Oat No! (an Oat Wine); Signpost Old Ale; Chris' Tall Ale 2.0; SSB (Signpost Sour Blonde); County Western Bottled - NB Ares' Biere de Mars; Ol' Bitter Bastard; Chris' Tall Ale; 4 small batch sour blends - 1 w/ cherries and 1 w/ peaches; Back To School Porter w/cacao & vanilla; Signpost Creek Paint Cider; Signpost Oud Bruin; Land of Pils and Honey, Imp. Saison with Clover Honey; Ad Hoc Berliner Weisse Kegged - BBD WIPA (but I think it has chlorophenolics); Keg #2 is EMPTY!