StarSan--Stable when diluted?

[LawMonkey]

A quick question. I've got a bit of starsan that I mixed up and put in a plastic spray bottle that's been sitting out on the sink for a while. It's a clear bottle in an area where it does get light. I did it as a handy way to conserve solution and (especially) for sanitizing individual bits of equipment.

So, is starsan solution stable once it's mixed up? IF so, for how long?

(I have the same question about iodophor, since I don't much like starsan--the foaming bugs me!)

 

[homebrewer_99]

Iodophor is good up to 24 hours.

Star San is good for months...

 

[Thalon]

StarSan is basically an acid bath. It loses effectiveness only when the pH of the solution goes above 3.5. So as long as it's a sealed container, it should stay effective for a very long time.

I'm gonna try and look up the link to the audio clip where I learned this from.. it was an interview with the chemist that designed it, one of the founders of Five Star Chemicals.

EDIT: this isn't quite what I was looking for, but the info may be here.

EDIT2: Found it!

EDIT3: By the way, diluting it with water will raise the pH of the solution since water is (defined as) pH 7. So the answer to your question is no, StarSan is not stable when diluted past its recommended concentration.

 

[FlyGuy]

You can 're-energize' it, though, by adding some fresh StarSan to the solution.

Star-San will keep longest if you use distilled or de-ionized (e.g., reverse osmosis) water. The minerals in normal tap water react with the detergents, causing it to become cloudy -- an indication that it should be replaced.

 

[abracadabra]

Iodophor will keep but you'll have to keep it out of sunlight. The color is a good indication of it's effectivness.

The people that sell it recommend you throw it out after 24 hours.

But in a closed container kept out of the sun I've used mine for a month or more and never had an infection.

That being said it's pretty cheap so if there was any question I'd mix a new batch.

As far as the PH of water you can get a pool test kit for about $5 and you can find out what your water's ph is. Mine is in the acidic range around 6.3-6.5 if your water was in the alkaline range above 7 that would neutralize a portion of your Star-San.

Don't be afraid of the bubbles the bubbles are your friend.

 

[AiredAle]

As long as the pH of the Starsan solution is below 3.5 (as stated above) and the solution is clean not cloudy, it is infinitely stable. I have a similar sprayer bottle that I've used for several months that is still clear, still foamy and I (fingers crossed) believe is still sanitizing. I have noticed it makes the sprayer mechanism stick a bit, and I have to pump it a bit to free it to work properly.

I've also noticed that if I leave Tygon tubing (plasticized vinyl tubing we all use) soaking more than a day or so in StarSan it brings the plasticizer to the surface. This makes the tubing sticky or slimy to the touch, and I won't use it to siphon beer, but save it for bleeding car brake lines. Don't really want to dissolve that phthalate plasticizer in MY beer, doncha know.

 

[LawMonkey]

Thanks for the help, guys. I'll keep my bottle around for spot sanitizing and figure out some way to check the pH. I had a bit of a problem with a bad batch, where I used the spray bottle to sanitize the inside of bottles, but I suspect that may have had other causes...

 

[b767fo]

I mixed up a 5 gal solution of Starsan in a spare bottling bucket using tap water (from a well). It turned cloudy right away. So...is it already bad or will it turn bad sometime in the future and I just won't be able to tell?

 

[Got Trub?]

I mixed up a 5 gal solution of Starsan in a spare bottling bucket using tap water (from a well). It turned cloudy right away. So...is it already bad or will it turn bad sometime in the future and I just won't be able to tell?

Its bad. As mentioned above if it is cloudy it is no longer effective. You will need to use distilled or dionized water rather then your tap water to mix it with. I too make up a large batch in an extra bucket and use it for weeks to months as long as it is clear so your cost if you have to buy water won't be too bad.

 

[b767fo]

Well then I'll dump it and get some distilled water. Thanks for the response. I gotta say I really like this forum; I've learned more stuff from here just reading along than I ever learned from my brother-in-law, and he runs a microbrew out in OR!