How long does Star San last?

[sgtpeppr56]

Was going to mix up a gallon of starsan to use for bottling today. Would it still be good to use for brewing tomorrow?

I was gonna keep it in a old gallon milk jug.

Thanks and brew on!

[RickBeer]

Weeks. Perhaps longer. PH Strips can test it, or you can keep it for 3 weeks, use it in a 2nd batch, then toss it as I do. $.10 per gallon for 2 batches = less than $1.00 per year.

I only mix up 0.8 gallons as that is exactly a teaspoon.

[berryman]

I always keep it for a few weeks, I like to store it in a clean 5 gal. carboy then when I secondary I'm all ready to go, or sometimes I store it in a couple of my LBK's. As Rick said a few weeks should be fine, but much after that you really should test it.

[Bluejaye]

StarSan will keep for weeks in a container (i.e. bucket, milk jug). If you have a pH meter, you know it is ready to throw out when it goes above 3.0. I never worry about it because I go through it before that would even happen.

And of course, this assumes you are keeping it clean, and not dipping spoons filled with wart into it, etc.

[Brewbirds]

The best way to keep Star San is to use RO water from the store to mix it; it can last months this way as long as you don't contaminate it (i.e. pour used batch back into container).

Star San is effective because it is a strong acid that creates a inhospitable environment for the bacteria etc. we don't want in our beer.

The reason people advise using a PH strip to test the viability of the solution is because minerals etc. in regular tap water can change the PH of the mixed Star San solution rendering it ineffective.

RO water has essentially been "scrubbed" of any potential PH challenges so that the solution will stay unchanged once mixed unless it is contaminated.

If you mix Star San in tap water and it turns cloudy immediately or within a day or so DON"T USE IT your water is "breaking" the Star San and it won't sanitize.

Mix the stuff (with RO water) in large batches; it will encourage you to use more of it and sanitizing is a good thing. If you don't already have one get a chemical resistant spray bottle (Walmart sells them) and have it in the kitchen/brew station so you can zap counter tops, lids, packaging etc. right through the brew session.

Hope this helps.

[Inkleg]

I mix mine 5 gallons at a time in a 7.5 gallon bucket with a Gamma lid on it. Makes it very convenient to access not having to fight a bucket lid.
I've mixed it and still have the pH read below 3 at two months. I use these pH strips to check before I use it. Still have the same bottle of strips that I purchased over 2 years ago.

Careful storing Star San in a milk jug. It is an acid and can weaken the seam and cause it to leak. The jug I had leak had Star San in it for at least a month. Just something to be aware of.

[jimjohson]

Careful storing Star San in a milk jug. It is an acid and can weaken the seam and cause it to leak. The jug I had leak had Star San in it for at least a month. Just something to be aware of.

I got a year and 8 months out of my milk jug. I didn't think about the acid weakening the seams, thought I had screwed up.

I make star san up in gallon batches and they typically last 2 brewing and 2 bottling cycles, before I just don't have enough left and have to make some.

[DaYooper]

Ive kept mine for several months. I really dont use that much since I use a spray bottle, and for bottling I prefer OneStep as I tend to make a mess and it is less caustic. Once mixed, OneStep has a limited shelf life and I would not use much longer than overnight, although in the past I did since I did not have this collective wisdom to advise me not to do that. Never had a problem.