PBW solution turned blue?

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PlexVector

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I have a Marks Keg/Fermenter cleaner and the well water was clear when it started and then when I came back from dinner it had turned swimming-pool blue. I used one tablespoon/gal of PBW and I am recirculating it through my RIMS to keep it around 120F. I also rigged it through my plate heat exchanger to clean it again in prep for the a brew day this week. Could it be a reaction with the copper in the heat exchanger? The RIMS has an ultra low watt density heating element that is for high lime content water, which is the dark color rather than bright SS. Should I be using the SS heating element?

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jtratcliff

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My DIY PBW (oxiclean & TSP90) gets fairly bluish when I first mix it up with city tap water.

Do you have pH test strips? As long as you're under 3, you should be fine.




Edit to add:

Ignore this. I'm an idiot. It's star san that needs a pH under 3, as pointed out below.
I still get slightly bluish water from DIY PBW in a white bucket, though...
 
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PlexVector

PlexVector

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Everything had a basic cleaning from the last brew day, but I wanted to give everything another hit since I had not brewed in a while, so the pH should have been okay. I had some old test trips that will go that low I think. I'll test it. My well water is just a tad acidic anyway. I don't remember it being that blue, although this is the first time its been in a white container.
 

Hopper5000

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My DIY PBW (oxiclean & TSP90) gets fairly bluish when I first mix it up with city tap water.

Do you have pH test strips? As long as you're under 3, you should be fine.
PBW is a base. I think you might be thinking of Starsan having to be below 3?

Mine has turned blue before too. As long as it cleans I don't think you have anything to worry about.

You could always email the manufacturer...
 

flars

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The presence of copper will show a blue flame in gas chromatography. Your water source could be part of the reaction.
 

Shooter

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I suspect the copper in the exchanger is the problem. I notice I get a blue color initially when clearing my nitro faucet after letting it soak with cleaner. This doesn't seem to happen when soaking it with anything else.
 

IslandLizard

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Amazing!

I recirculate homemade PBW through my DudaDiesel plate chiller for up to an hour at 160-180°F. The PBW water always turns yellowish/brown from wort and hops deposits in the chiller. Yours must be ridiculously clean to see this.

Some Copper salts tend to be greenish or blue. Most plate chillers we use are brazed with copper, so that could be a source. Did you store your chiller filled with Starsan (an acid)?
 
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PlexVector

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PBW is a base. I think you might be thinking of Starsan having to be below 3?

Mine has turned blue before too. As long as it cleans I don't think you have anything to worry about.

You could always email the manufacturer...
Yep, PBW is a strong base. So, it may be copper hydroxide. Does anyone know if this is detrimental to the plate exchanger?


EDIT:
The PBW liberated some of the copper brazing material, not enough to cause problems but enough to make the water blue with copper hydroxide. If you are concerned with residual copper hydroxide in chiller, soak inside with sodium bisulfite followed by hot water flush.
Okay, I found this in an old thread. I guess I will do a good rinsing before I use it again. Don't know what the sodium bisulfite does chemically to the copper hydroxide.
 
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PlexVector

PlexVector

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Amazing!

I recirculate homemade PBW through my DudaDiesel plate chiller for up to an hour at 160-180°F. The PBW water always turns yellowish/brown from wort and hops deposits in the chiller. Yours must be ridiculously clean to see this.

Some Copper salts tend to be greenish or blue. Most plate chillers we use are brazed with copper, so that could be a source. Did you store your chiller filled with Starsan (an acid)?
This one is a dudaDiesel. After the last brew day it got a good cleaning. I would hook it up to the sink hot water with silicon hose. pinch the output hose and the input hose would swell and build pressure and then release. It spit like crazy. then reverse direction. It was amazing as to what came out. Did that about 15 times before running clear.
 

IslandLizard

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This one is a dudaDiesel. After the last brew day it got a good cleaning. I would hook it up to the sink hot water with silicon hose. pinch the output hose and the input hose would swell and build pressure and then release. It spit like crazy. then reverse direction. It was amazing as to what came out. Did that about 15 times before running clear.
I have the short and tall chiller (30 plates) and must have more deposited gunk in there than you do. After the back and forth purging runs clear, my PBW always comes out a shade of yellow/brown, probably masking the blue copper salts. Is this a wake-up call?

I used to store mine filled with Starsan, until I read that the copper brazing can be attacked by the acid. So I shake it dry now. I bake mine regularly at 350-400°F, with bread or pizza, to sterilize.

Have you tried with just Oxiclean by itself? My home compounded PBW only contains generic Oxi-product and Sodium Metasilicate (TSP-90). There's plenty of OH- available in those alkaline cleaning solutions to attack the Cu.

Real PBW contains Sodium EDTA, a strong metal ion sequestering agent. It can suck the metals out of glass, over time.
 
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PlexVector

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I have the short and tall chiller (30 plates) and must have more deposited gunk in there than you do. After the back and forth purging runs clear, my PBW always comes out a shade of yellow/brown, probably masking the blue copper salts. Is this a wake-up call?

I used to store mine filled with Starsan, until I read that the copper brazing can be attacked by the acid. So I shake it dry now. I bake mine regularly at 350-400°F, with bread or pizza, to sterilize.

Have you tried with just Oxiclean by itself? My home compounded PBW only contains generic Oxi-product and Sodium Metasilicate (TSP-90). There's plenty of OH- available in those alkaline cleaning solutions to attack the Cu.

Real PBW contains Sodium EDTA, a strong metal ion sequestering agent. It can suck the metals out of glass, over time.

PBW is probably being used in copper kettles and fermenters. I would think this would not be a new subject.
 
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PlexVector

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Before things get out of hand I did a quick google on PBW and copper. Sounds like PBW is okay with copper and that the copper brazing inside of my chiller is probably nice and shinny in that the PBW removed some of the oxide layer.
 

IslandLizard

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Oxide layers tend to protect the underlying, more reactive bare metal. So dissolving it still corrodes, slowly but surely. We probably shouldn't worry so much and stick to more basic things we understand better, like brewing beer! :mug:
 

maierhof

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I have also seen this - as my carboy/keg/keggle cleaner has a copper shaft attached to the pump itself. It is the copper and time that you had it cleaning the copper.

Shorten your cleaning cycle if you don't want the color, but IMHO - just rinse the s#!t out of it and you are done. Nothing to fret over.

At first when I saw this color I thought - omg I broke a seal in the pump - and was just stumped trying to figure out how this happened...

Then I got a piece of copper and stuck it in small pool of 120*F PBW for a few hours - there you go. :mug:
 
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PlexVector

PlexVector

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Thanks all. Ignorance is not bliss after all. At least not in home brewing. I solved the problem by not using white containers. :)
 

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