I’ve been mixing up fresh star San & reusing it a few times before dumping it. I read an article last night that said if it is cloudy it needs replaced. Mine is cloudy as soon as I mix it up!!! Should it be clear when it is newly mixed? How long does everyone use star San before mixing a new batch?
The cloudiness is due to your water chemistry I believe. Mine is also always cloudy. As long as the pH of the mixture is at or below 3.0 then it is still effective. Since I have no way of checking pH my MO is to mix a batch right before I bottle. I tend to brew a new batch soon after I bottle so the sanitizer is used for one bottling session, one brewing session, then for various other things I’ll need it for like checking gravity, sanitizing secondaries, making starters, etc.
It may be good for longer but I’d prefer to err on the side of caution and 3-4 weeks per 1oz of starsan won’t break the bank.
I’ve heard star san lasts pretty much indefinitely if mixed with distilled water. I’m guessing your water chemistry determines how fast it goes bad. I just moved from a place with pretty hard water where my star san was always cloudy. I haven’t got my water report back here yet but my star san stays crystal clear.
I mix mine with distilled water stays nice and clear. I usually save a squirt bottle full of it before dumping it. However this last time I made 5 gallons of it I saved the gallon jugs and poured the star san back into them. I would have done this sooner if I had though of doing it that way. I just made sure to clearly label them. Like Matt said its all about the pH. Although I also don’t have any way of checking it at the moment. I need to buy some pH test strips.