So… I make up a solution of a cleaner and want to use it, at some point in the future from five minutes to five months. But how long will it really last? For a StarSan solution, the forum consensus seems to be that a pH is < 3 means that is still effective. They are conservative, though. A FiveStar rep. said to be sure it is below 3.5. Good stuff! How about other cleaners? PBW is good for up to 8-12 hours. Anyone have any hard limits for other cleaners and sanitizers? e.g. Campden sprays, etc.? Chlorox sprays (multiple uses)?
Me do use. Pdw powder wash. For the cleaning. Of my carboys. And kettles. Quick rinse afther soaking. Than i sanatize. With starsan. Use for the rest starsan. During the actual boil to keep my hoses spoon airlock. And other things. Sanatized. In a bucket but have been using. Deluted bleach for cleaning. My glass carboys as well. And again rinse sanatize with starsan
I keep a gallon of One Step and another of San star under the sink for cleaning bottles as I drink them or for quick sanitizing before dry hopping. They seem to last for months without a problem. I also have a small spray bottle with San Star I keep around. I haven’t checked PH but I’ve used if for a while and never had contamination issues.
I wouldn’t use star-san with a pH of 3.5, there are plenty of yeast and bacteria that can live happily at that pH. Not that it’s the only factor to consider, but still… mix it with distilled water, and it should last for months and months.