[animaldoc]

Charlie Talley did a great interview that you can listen to on the Brewing Network - download the podcast

http://thebrewingnetwork.com/shows/The-Sunday-Session/The-Sunday-Session-03-19-06-Sanitation-w/-Charlie-Talley

Tells you all about Star San and tubing, lifespan, cloudiness.

Reader's Digest version -- BDDS (benzyldodecylsulfate, I believe) the detergent in StarSan is electrostatically attracted to the plastic in the tubing and migrates into the pores of the plastic creating that white haze.  It's not actually damaging the plastic.  Star San becomes cloudy beause of the BDDS binding with metal ions in the water and coming out of solution.  Using RO or distilled water *dramatically* prolongs the cloudy-free usage of Star San -- it still works when cloudy as long as the pH stays under 3.5, but it will leave a detergent film.

-- Scott

[tschmidlin]

Actually, that makes perfect sense... Essentially, the charge of the plastic slowly adds positive charge to the solution over time, until the PH is high enough that it can no longer keep the surfactant (detergent) dissolved.  If you were only getting the goo on your plastic parts and the water was NOT getting cloudy, then that would be an indication that the plastic is being eaten away. 

If it's adding positive charge to the solution it would get more acidic, not less, but I get your point.  My point is, if the hose is absorbing H+ and making the solution less acidic, what makes you think it is not breaking down the hose?  That's how acid works to break stuff down, the H+ reacts with it.  So it's possible the cloudiness is the surfactant coming out of solution because of the rise in pH, because the hose is breaking down and getting gummy.  Or it's possible the gumminess is the surfactant.  We'll see what Five Star says.

Ah, I see animaldoc's post - great info, thanks, I'll have to go back and listen to that one.

[richardt]

Also consider the fact that concentrated StarSan solution is:
stored and shipped to us in a plastic container (HDPE, #1),
often diluted (1 oz. Starsan in 5 gallons of distilled water) and stored in a 5 gallon Homer bucket (HDPE, #1),
often stored in and used to sanitize Better Bottles (PETE, #2),
routinely used to sanitize vinyl tubing (V, or PVC, #3).

It does not corrode or break down plastic.
Just make sure the pH of the diluted Starsan solution stays below 3 (use distilled water or water w/ very low residual alkalinity).
The StarSan solution will remain clear and there will be no slimy/gummy residue on your equipment and hoses.

[tschmidlin]

Also consider the fact that concentrated StarSan solution is:
stored and shipped to us in a plastic container (HDPE, #1),
often diluted (1 oz. Starsan in 5 gallons of distilled water) and stored in a 5 gallon Homer bucket (HDPE, #1),
often stored in and used to sanitize Better Bottles (PETE, #2),
routinely used to sanitize vinyl tubing (V, or PVC, #3).

It does not corrode or break down plastic.
Just make sure the pH of the diluted Starsan solution stays below 3 (use distilled water or water w/ very low residual alkalinity).
The StarSan solution will remain clear and there will be no slimy/gummy residue on your equipment and hoses.

Fair enough.  Although just because something is used to sanitize something doesn't mean it won't corrode it, chlorine and stainless for example.

[richardt]

True (re Cl and SS).  No disrespect intended at all, Tom--I just wanted to make sure that forum readers get the right idea before 'acid degradation of plastic tubing" became an urban myth and had its own Wiki entry. 

In fact, I sympathize--I, too, have a tendency to think aloud (or online) when I encounter a problem--and my comments and reasoning are not always correct.  That's what makes this forum so fantastic--we're all on the same journey towards a better understanding of brewing great beers and there are a lot of enlightening comments and tips from the pros/veterans here on this forum.

[tschmidlin]

True (re Cl and SS).  No disrespect intended at all, Tom--I just wanted to make sure that forum readers get the right idea before 'acid degradation of plastic tubing" became an urban myth and had its own Wiki entry. 

In fact, I sympathize--I, too, have a tendency to think aloud (or online) when I encounter a problem--and my comments and reasoning are not always correct.  That's what makes this forum so fantastic--we're all on the same journey towards a better understanding of brewing great beers and there are a lot of enlightening comments and tips from the pros/veterans here on this forum.

No worries, I'm from NJ, I have a thick skin and a tendency to vigorously defend my position.

But I'm also a scientist, and I prefer to know the truth than cling to a failed hypotheses.  I just take some convincing sometimes.