Is my Star San still effective?

[MaltySmoOTH]

so, I have a bottle of Star San that I lost the cap to about 2 years ago. I have since been covering it up with a sandwich bag.
Will exposure to oxygen over time compromise it's effectiveness? ..

[NateBrews]

If it still looks normal when it is mixed up, I would probably not worry about it. That said, the cost of a new bottle of star san pales in comparison to a ruined batch of beer.

[brewinhard]

2 years is quite a long time. But, I did use a bottle of star-san with aluminum foil as its cap for quite a bit of time with no issues whatsoever. I think that stuff is pretty acidic in its concentrated form.

[Charlie]

The cap of one of my bottles of Star-San broke too. That ought to be a known defect.

There are a lot of caps that will substitute. Just look around in your cleaning and auto supplies. Meanwhile some plastic wrap and a rubber band will keep the air out of it.

Charlie

[cascadiabrewer]

make a small test batch and check with a pH meter if it is above 3 pH it is no longer an effective sanitizer.

[Ozwald]

An actual, logical test? Are you serious? I think we should just keep waving sticks at it & making guesses.

[cascadiabrewer]

Ha okay we'll meet in the middle....keep waving a stick as long as it is a pH strip!

[Ozwald]

Pfft. You and your new fangled magic.