Used plate chiller corrosion, clean with oxyclean?

[Nemanach]

I just got a used plate chiller and there is a little green corrosion on the outside. What should I used to clean any possible corrosion from the inside? Will oxyclean work or should I stop at the store and get PBW?

 

[Nemanach]

I did a little more searching and it seems acid cleaners are best. Think a cup of vinegar in a gallon of water recirculated for a while would do it?

 

[augiedoggy]

I did a little more searching and it seems acid cleaners are best. Think a cup of vinegar in a gallon of water recirculated for a while would do it?

Just be careful the acid will weaken the copper brazing over time I believe.

 

[mpmccann]

I have baked my plate chiller, used OxiClean, but I am now using home made PBW which I believe is working the best for all brewery cleaning. You can find the recipe here https://www.homebrewtalk.com/showthread.php?t=467655...
I might also add, you will never get it completely clean. There will always be some junk that comes out no matter how many times or how long you recirculate cleaner through it. Just the way it is my friend. I ended up using a SS mesh strainer that hangs on the side of my BK for all hop additions and Irish moss, etc. to keep stuff out of the chiller.
Hope this helps...

 

[Nemanach]

It actually seems very clean. Nothing comes out when I flush it and flow is great. My only concern is hidden green copper corrosion which I understand to be poisonous. I plan on recirculating the last 15 minutes of boil through it and will be using a hop spider so it will be sterilized that way, I’m not really concerned about a little hidden hop material.

 

[thekraken]

Verdigris, nasty stuff: https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+258

Acute exposure and attendant copper toxicity is possible when cooking or storing highly acidic foods in unlined copper vessels for extended periods, or by exposing foodstuffs to reactive copper salts (copper corrosion, or verdigris). Continuous, small ("chronic") exposures of acidic foods to copper may also result in toxicity in cases where either surface area interaction potentials are significant, pH is exceptionally low and concentrated (in the case of cooking with, for example, vinegar or wine), or both, and insufficient time elapses between exposures for normal homeostatic elimination of excess copper.

https://en.wikipedia.org/wiki/Copper_toxicity

I remember reading somewhere in the forums a while back about someone giving an initial soak in a vinegar solution, then rinsing it out, then repeat until the solution no longer turns blue/green. Though I don't understand how soaking in vinegar solution in even clean copper wouldn't in if itself cause the solution to turn green.

So how about rinsing it really well with hot vinegar solution, then rinse out even better with pbw? idk... What's copper's reaction to high pH (pbw) solutions?

http://howtobrew.com/book/appendices/appendix-b/brewing-metallurgy

 

[augiedoggy]

I ended up using a SS mesh strainer that hangs on the side of my BK for all hop additions and Irish moss, etc. to keep stuff out of the chiller.
Hope this helps...

Same here but since Ive used one from the start I have had no issues with solid stuff or buildup going in or coming out of my plate chiller..(knock on wood)

 

[augiedoggy]

Verdigris, nasty stuff: https://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+258


https://en.wikipedia.org/wiki/Copper_toxicity

I remember reading somewhere in the forums a while back about someone giving an initial soak in a vinegar solution, then rinsing it out, then repeat until the solution no longer turns blue/green. Though I don't understand how soaking in vinegar solution in even clean copper wouldn't in if itself cause the solution to turn green.

So how about rinsing it really well with hot vinegar solution, then rinse out even better with pbw? idk... What's copper's reaction to high pH (pbw) solutions?

http://howtobrew.com/book/appendices/appendix-b/brewing-metallurgy

This is exactly why unlined copper pots and pans are not sold anymore and why copper is banned wine/food contact in wineries. brewing is one of the only industries left where direct contact is allowed along with cheese making I believe..

 

[hotwatermusic]

Just to be clear is the OP posting about a copper brazed plate chiller? If so and there is signs of verdigris on the outside, I would just suggest taking the loss and wasting it. Can you disassemble the plates for a proper cleaning? I had a hand-me-down immersion chiller with signs that I could never get clean and that was with access and scrubbing.
...But Bar Keeper's Friend might be another option. With a rinse immediately after.

 

[Nemanach]

Duda responded to my email on the chiller. They suggested soaking in vinegar for 5 minutes, rinsing really well then flushing with lye, PBW or baking soda to neutralize. They said the vinegar needs to be flushed well or it will make the problem worse.

When I drained the vinegar it was definitely had a blue/green tint to it. I'm not sure if that means there was verdigris or if that would happen anyways with vinegar and copper. I throw a piece of hard copper pipe in vinegar for 5 minutes to test and didn't see any green but that could be because of the alloying.

Attached are pictures from the exterior of the chiller. This was after I splashed vinegar all over it so there wasn't as much. You can see a little in the corner photo.

Edit: I can't understand why the pictures are upside down. They were upside down when mine are correct on my computer, I flip them on my computer and they are still upside down.

 

[day_trippr]

Allow me...





Cheers!

 

[Nemanach]

This morning I acidified water to 5.1 pH which should be similar to wort. I let it sit in the chiller for 30 minutes. I dumped it into a glass jar and couldn’t detect any blue coloring, the water tasted sharp but I assume that is the acidity, I don’t taste copper in it. It makes me feel better but I’m not sure if it’s a false sense of security. Maybe I’m making too big of a deal about a small amount of exterior corrosion.

 

[thekraken]

This morning I acidified water to 5.1 pH which should be similar to wort. I let it sit in the chiller for 30 minutes. I dumped it into a glass jar and couldn’t detect any blue coloring, the water tasted sharp but I assume that is the acidity, I don’t taste copper in it. It makes me feel better but I’m not sure if it’s a false sense of security. Maybe I’m making too big of a deal about a small amount of exterior corrosion.

I'd try it with the liquid boiling hot and recirculating.

 

[Jayjay1976]

Maybe recirc with starsan, I know it brightens up tarnished copper immersion chillers.

 

[Nemanach]

Good suggestion on the recirculation and hot solution. Definitely a green tint. Maybe this isn’t going to be saved.

 

[processhead]

So are you assuming that since there is visible corrosion on the outside, that the inside is also corroded?
Not saying that it isn't, but I don't think you can just assume that it is either.
When I recirculate hot cleaning solution (PBW) through my copper CFC for a long time, I will sometimes get green/blue tinted coloration to the solution. This even when it is clean. I think some metallic copper will dissolve and react with strong acid or alkaline solutions under the right conditions.

 

[Nemanach]

The outside is what brought up the concern. I put vinegar in it for 5 minutes and it came out very blue which confirmed my suspicion. I then ran 5.1 pH water through it which should be similar to wort and got light blue water in the post above. Since then I have soaked it in vinegar for 5-15 minutes each time for ~5 cycles, each time the vinegar was blue. The vinegar at the end of my cycles was certainly much better than the first time but it was still blue.

As a test I soaked it for 15 min in vinegar. I also soaked my immersion chiller in a different bucket with the same amount of vinegar. The plate chiller vinegar had a light blue tint, the immersion vinegar was clear. I wanted to see if the blue color was normal for clean copper.

As a final test I again ran 5.1 pH water through it while boiling for 15 minutes. Then circulated for another 15 min when the burner was off. I got a light blue solution. I did the same test with my immersion chiller and still got a blue solution but it was much lighter, barely noticeable as blue. So some comes off with the immersion and more comes off with the plate chiller.

The blue against the immersion chiller control has me nervous but I’m not educated enough to know how much is too much. The immersion chiller is probably an alloy which may slow the leaching of copper and it may be completely normal for the plate chiller to add more copper to the water but I don’t know. I would much prefer to just use this chiller and be done but I don’t want to risk my health and my families health by feeding everyone something dangerous.

 

[Shwagger]

A side note to cleaning. I boiled, flushed, oxyclean, etc my shirron all the time. Seemed clean. Then one day I soaked it in BLC and water for a few minutes. A ton of gunk came out. Incredible.

Now, immediately after I'm done cooling wort, I backflush it with oxyclean and water, then sanitized with star San. Let it dry upside down, and cap it.

Damn things work great but love getting gunk