Can Star San damage plumbing?

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HectorJ

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I have my little brewery in a basement and use the "soak" method to disinfect my fermenter. This is run out into a reservoir/pump contraption that pumps the liquid up a large pipe and out into the regular municipal waste water. For the moment, I have been running a lot of water while/after emptying the fermenter so dilute / wash the Star San out of the reservoir.

I know the pump includes a blade that chops up solid waste, it is made of metal and plays an integral part of the reservoir/pump machine.

Is there any risk of the Star San causing an issue with any parts of the pump / reservoir? I have read on here it can cause problems for metal, but what about plastic / rubber ?

Thanks,
Hector
 
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Golddiggie

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The actual acid level in mixed Starsan isn't enough to damage anything. If being run into municipal waste system, I wouldn't worry about it one bit. I run some water after dumping mixed Starsan down the sink where I am. BUT, I'm on a septic system, so running the water after is in the advisable list. There have been more than a few times I've dumped a bucket of Starsan (3-5 gallons of it) onto plants and they gave zero F's. If plants can shrug it off, I don't think it will do anything to plastic/rubber. It's NOT like you're using it at full concentration.
 
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HectorJ

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Thanks! I'll continue to run the water to empty the reservoir/pump, it's not mine (I rent the space) and don't want a tonne of someone else's dirty toilet water backing-up into the brewery...
 

mashpaddled

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I wouldn't make a regular practice of dumping undiluted starsan into the drain (I don't know why you would) but even occasionally you are unlikely to cause damage. Undiluted starsan I believe is around 1.5 ph while lemon juice and vinegar are around 2-2.2. Vinegar is a common home pipe cleaning chemical so not much of an issue there. I wouldn't unload gallons of vinegar into my pipes but a small amount isn't going to create damage.
 

RufusBrewer

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If you are on municipal sewer and your sewer pipes connect with your neighbors pipes and those go on to some city processing plant, do not think twice.

If you are on your own septic tank, at some point you might (a big might) pour in too much StarSan into your septic system. At normal doses and normal volumes, and normal frequency, hard for me to imagine A homebrewer can induce a problem.
 
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HectorJ

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If that's your concern, you have MUCH larger issues (than from Starsan).

It would only be my concern if Star San could somehow damage the plumbing (there is a 1 way valve that prevents the back-flow).
 
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HectorJ

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I wouldn't make a regular practice of dumping undiluted starsan into the drain (I don't know why you would) but even occasionally you are unlikely to cause damage. Undiluted starsan I believe is around 1.5 ph while lemon juice and vinegar are around 2-2.2. Vinegar is a common home pipe cleaning chemical so not much of an issue there. I wouldn't unload gallons of vinegar into my pipes but a small amount isn't going to create damage.

Thanks. I'm not dumping undiluted, it's properly diluted to a PH of below 3 (usually 2.something)
 

Beermeister32

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I used to leave my stainless steel aeration stone in a jar of Star San solution. The 45 degree stainless flare fitting on the end of it began to corrode and pit. There definitely are some grades of stainless which can be affected after a long soak like this. Concentration probably plays a factor as well.
 

Vale71

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I used to leave my stainless steel aeration stone in a jar of Star San solution. The 45 degree stainless flare fitting on the end of it began to corrode and pit. There definitely are some grades of stainless which can be affected after a long soak like this. Concentration probably plays a factor as well.
Assuming the fitting was soldered on this was probably caused by welding too hot and causing the stainless to locally lose its properties.
 

Golddiggie

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Assuming the fitting was soldered on this was probably caused by welding too hot and causing the stainless to locally lose its properties.
And/or the maker failed to fully passivate the stainless post manufacturing/welding. Since anything touching beer (or anything for fermenting), when stainless, should be a 300 series (303/304/316) it shouldn't have any impact from sitting in Starsan. Of course, when I was using the O2 stone (on a wand) I would clean it and then wrap it in a piece of aluminum foil to keep things off of it. Not leave it in Starsan for X weeks between uses.

People use PVC pipe to hold concentrate ferric acid (for etching damascus blades) all the time. If that doesn't do damage to the pipe, then mixed Starsan sure won't.

Keep in mind, we often put out hands in buckets of Starsan (when dunking items or fishing items out) and it has zero impact. Hell, it doesn't even bother cuts on my hands. I've also run Starsan through a sump pump (running back into a CIP ball in a conical fermenter) and have had zero pump issues.

When I was on city water (and sewer lines) I didn't think twice about pouring Starsan down the drain. Zero impacts were had. As already mentioned, people run a LOT stronger solutions through the pipes in their homes than Starsan (and/or PBW mix).
 

Beermeister32

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I'll take a look I think it was press fit. Here's an article from corrosionpedia on stainless corrosion resistance:

Also a picture of pitting on 304 stainless:
 

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sibelman

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I recently saw some corrosion on the swivel nut of a flare swivel that had been in diluted StarSan for a few days. Looks like brass that has lost most of its chrome plating. The (stainless?) barb was not visibly affected. (I've bought most of my swivel flares from BrewHardware, which does not mention what they're made of.) So @HectorJ may be right to be a bit concerned -- who knows what metals are in his drain's check valve?
 

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HectorJ

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I recently saw some corrosion on the swivel nut of a flare swivel that had been in diluted StarSan for a few days. Looks like brass that has lost most of its chrome plating. The (stainless?) barb was not visibly affected. (I've bought most of my swivel flares from BrewHardware, which does not mention what they're made of.) So @HectorJ may be right to be a bit concerned -- who knows what metals are in his drain's check valve?

Thanks. I will indeed keep the water running after I empty Star San into the reservoir/pump. Seems the prudent thing to do imo...
 

RolandD

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I recently saw some corrosion on the swivel nut of a flare swivel that had been in diluted StarSan for a few days. Looks like brass that has lost most of its chrome plating. The (stainless?) barb was not visibly affected. (I've bought most of my swivel flares from BrewHardware, which does not mention what they're made of.) So @HectorJ may be right to be a bit concerned -- who knows what metals are in his drain's check valve?

I've had diluted StarSan take the chrome off brass, as well. I just don't leave things to soak for prolonged periods, now. The loss of chrome is just cosmetic.
 

Beermeister32

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Here is a photo of the stainless steel carbonation stone I discussed. After use, this was boiled and then stored in a glass jar with Star San solution.

It is a mild, human tolerant acid, I know you can digest it, but given time, it does have a corrosive affect on some metals. Not all stainless is the same, some are more prone to corrosion than others, but remember you have the one factor not ordinarily discussed - not concentration, but “time” - deep time soaking in that solution can have a corrosive affect on some alloys.

Note the alloy of the stainless stone is unaffected. The alloy of the stainless fitting was affected by the solution.
7ADC9B04-87C1-46DC-8028-9160C89D9121.jpeg
 

Golddiggie

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I had my Spike carbonating stone filled with Starsan solution for a few days. Zero effect. Which leads me to believe it's actual 303/304 stainless. Who knows what the fittings showing being effected by Starsan solution actually are. I've left Starsan inside kegs for months with zero effect. So, if your "stainless" fittings are effected by Starsan, then chances are they're a lower grade of stainless steel than you were either told or lead to believe.

There's a reason kegs are 303/304 stainless, as are most things for brewing. I'm sure many think the same grade when they read "stainless steel" for an item. But without it being called out, or stamped on the item, it's hard to really KNOW what it is. Especially for small items like swivel nut nuts. Since those are not (typically) in contact with beer, they really don't NEED to be stainless steel.
 

Beermeister32

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I have a lot of experience with metals, it is entirely based on the alloy used by the manufacturer.

Those swivel nuts are usually brass with a quickie nickel plating, not surprising they are corroding.

Like I mentioned, extended time of contact is an important variable here.

I have a number of stainless aircraft fittings, Mil-spec items are held to higher standards than the unknown allows coming out of China. A lot of small batch items like carbonation stones might use items available from a local supply house.
 
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Beermeister32

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So, if your "stainless" fittings are effected by Starsan, then chances are they're a lower grade of stainless steel than you were either told or lead to believe.
We’re not always told the fine details of alloys, builders of parts aren’t always either so all sorts of things are used on limited production items. We just buy the stuff they sell through the beer vendors.
 

sibelman

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I see two related concerns here: avoiding corrosion of our equipment, and avoiding unwanted additions to our beer. The lack of visible corrosion on high quality stainless parts indicates that they tolerate Starsan well, but the corrosion we've seen suggests that even passivated 304 could lose some iron, nickel and chromium - but how much? Negligible, I hope. But probably a wee bit more than @Golddiggie 's "zero [visible] effect".

Doubtless, there's a small puddle of sanitizer in the bottom of the keg I've been purging with fermentation CO2 output. I'll be transferring beer into the keg on top of this. I'm not happy to imagine that some heavy metals may be making their way into the beer. But, of course, there's no such thing as total purity 😏
 

Golddiggie

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We’re not always told the fine details of alloys, builders of parts aren’t always either so all sorts of things are used on limited production items. We just buy the stuff they sell through the beer vendors.
If they claim an alloy, or that it's "stainless steel" it really SHOULD be the low 300 series when it comes to brewing. Since that's "industry standard" for such things. Most are 303/304 but some are 316. The alloy matters, as well, when it comes to TIG welding to make sure the correct filler rod is used.

I figured the nuts for swivel nuts were plated due to how they reacted to Starsan after a short amount of time. The barbs, though, appear to be good stainless since they are all "honey badger" when it comes to Starsan.
 

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