PBW/ Starsan Lifespan

[Mark_tries_brewing]

Hey, pretty basic question here but I was wondering about mixing up and then keeping PBW and/ or starsan solutions. Right now I am soaking a corney with PBW, is it okay to use that same 5 gallons and siphon from one to another if they are relatively clean? Also can I mix up a bucket or some kind of plastic bin full of starsan and then just soak items in there when needed but keep the bucket? If so for how long before it will no longer effectively sanitize? Any kind of experience with lifespan/ effectiveness of PBW and/ or starsan over time would be appreciated.

 

[deepcdan99]

I keep starsan in a closed 5 gallon bucket and and spray bottle and use it for about a month. never had any problems. You can check the PH with a test strip, after it falls above or below a certain point it is no longer any good. Some say "when it gets cloudy" but I don't wait that long. PBW, can be used over and over and over. I have soaked probably 5 kegs in the same solution, from one to the next. Though better results with warmer temps.

 

[Mark_tries_brewing]

Is there a specific pH range that it should be within or just check and then if it has deviated/ has gotten cloudy it should be dumped?

 

[Captain Damage]

I heard a podcast interview with the owner of 5 Star, a couple of years ago. He said the oxygenating action of PBW is gone within 24 hours, and that OxyClean has a similar life.

 

[ja09]

I heard a podcast interview with the owner of 5 Star, a couple of years ago. He said the oxygenating action of PBW is gone within 24 hours, and that OxyClean has a similar life.

I can see that, but I keep a tub of oxy around for months to soak random beer and wine bottles for removing labels. Always seems to work fine, and keeps that slippery texture. I've also used this in my primaries and it works fine, but maybe not as effective as the first day.

And with starsan, mine is always cloudy within a couple days and I've never had a problem. I do check the pH every once in a while and try not to get it too dirty. Usually lasts 1-2 months.

 

[IslandLizard]

Is there a specific pH range that it should be within or just check and then if it has deviated/ has gotten cloudy it should be dumped?

From the Starsan Specs sheet (06/03!), the one that shows up in Google searches now:

When solution begins to cloud, sweeten with Star San or Phosphoric Acid. Solution must remain at a pH at 3 or below to maintain proper sanitizing level.

Beware, that sheet is dated June 2003. I'm quite sure I've seen a more detailed sheet before, where the fresh working solution pH was spec'd explicitly at 2.3.

In practice, the clouding seems to be a non-issue as long as the pH remains below 3.

I've kept Starsan in a plastic tub for several months (3-6). Yes it becomes cloudier over time, and even found a white chalky precipitate on the bottom and inside vinyl hoses (!), but it still seems to work just as well. I do measure pH at times and add some phosphoric acid when needed.

 

[IslandLizard]

I heard a podcast interview with the owner of 5 Star, a couple of years ago. He said the oxygenating action of PBW is gone within 24 hours, and that OxyClean has a similar life.

That's about right. The Sodium percarbonate in PBW (and oxiclean) is not very stable. Once dissolved, the oxygen starts to dissipate. I doubt it even takes 24 hours, perhaps in very cold water. I think the oxygen is gone or severely depleted within only a few hours after mixing, particularly in hot water.

If you've ever mixed it fresh in hot water you see the thousands of tiny bubbles rise. That's the oxygen!

So after the oxygen is gone, you're left with a solution of sodium carbonate (washing soda) and sodium metasilicate, and a little bit of sodium EDTA (sequestering agent). It still works fine as a cleaner, but without the benefit of oxygen action. The slick feel is from the detergents and the high pH.