Originally Posted by Beerrific
If you use deionized water and clean everything really well before sanitizing, it should last a very long time.
technically, RO water. however since I don't think you can de-ionize water full of minerals and a non-neutral pH, DI water has been RO filtered.
distilled would work in a pinch too.
my tap water is hard enough that star san starts off cloudy/hazy even though its still effective.
my next spray bottle (probably today actually) will be made with RO water so it keeps for a longer period.
also when it does go 'bad' you can add enough star san to get it back down to the correct 'effective pH' and its good again! so it really is economical.
Primary: English Mild
On tap: Pale Ale, Lancelot's Wheat, English Brown Ale, Steam Beer, HoovNuts IPA
Bottled: MOAM, Braggot, Raspberry Melomel, Merlot, Apfelwein, Pyment, Sweet mead, Cabernet
Gal in 2009: 27, Gal in 2010: 34, Gal in 2011: 13, Gal in 2012: 10