Long term storage of star san...

Was thinking about storing star San in a 5 gallon plastic water jug, and I was wondering if anyone has done this an is it safe... I don't know why it wouldn't be safe I'm just curious.

Do you mean storing a solution of water and star san in a plastic jug, or do you mean 5 gallons of "raw" star san (ie, unmixed with water)?

As long as you have relatively soft water, you should be able to store it for a few weeks.

You can test it with a ph strip. But I forgot what level is still considered usable.

As long as the the pH is in the low 2s it's still effective. Killing bacteria happens (this number will probably vary based on whos telling you and for what purpose) under a pH of 2.5. If you mix up a batch with RO or distilled water there wil be very little alkalinity to "use up" the acid.

I'm going from memory here as I did the math a while back... Properly mixed StarSan will be around 2.1. Let's just call it low 2s. As long as its still 50% w/w phosphoric acid, that was on the bottle last time I checked.

Use Distilled water...

+1 to what GotPushrods said about the pH. On the podcast on the sticky Charlie Talley said throw it out if it’s cloudy or the pH goes above 3.0. I just made a batch and measured pH 2.15.

Don’t forget about the detergent, it’s not just the acid. If I remember correctly Charlie said the acid weakened the bacteria and the detergent ruptured the cell. If it turns cloudy then the detergent has been weakened or depleted.

It would be a mixed solution. I have it just sitting in a 5 gallon bucket and I thought that a 5 gallon water jug would be a little bit easier to store