i typically keep mine for 2 or 3 months, but it'll depend on how many times i brew. if i've been using a batch for a while, i might re-dose it with a little more star san to ensure i'm back under the required pH. i should get some test strips... but i haven't.
when i'm ready to replace my batch, instead of dumping all of it i save a gallon or two in an empty milk jug. i then use that less-than-fresh star san in my blowoff tube setup.
What hops should I grow? Looking for cheap honey?
- Drinking: NHCPA (BPA and APA made with ingredients from Baltimore), 2 blends of a rye sour: ECY20 + ECY34, local sour cherry kriek #2, brett'ed Belgian blond on raspberries
- Aging: sour blond on second-use cherries, English Barleywine (half on brett), 3726 saison w/ brett x2 (dregs mix & Lochristi), GNO 3724 saison w/ brett mix, sour cherry mead, acerglyn, and a few other sours...