Chrome dissolved in beer?

[paulmic]

Hello all. This is my first post so hopefully it's in the right place and the following question's not too stupid.

I recently dry hopped a 19L batch of IPA by putting dry hops in a muslin bag in the FV (after primary fermentation had finished). I put a sterilised 25mm stainless steel ball bearing in the bag to sink it. It wasn't heavy enough so the bag sat just submerged under the surface. After a week, I removed the hop bag and put it to one side, racked off the beer and bottled it. The next day I got round to emptying the hop bag and found that the ball bearing had turned from nice shiny silver to a mottled matt black colour.

I then checked and realised that the ball bearing was chrome plated and I presume that the acidity of the beer has actually dissolved the chrome plating and exposed the steel underneath. Does this sound right and if so, have I poisoned the whole batch or is it still safe to drink? (It tastes OK).

Thanks in advance for your help.

[Jim]

Are you sure the chrome is completely corroded through? Have you tried cleaning it up to see what's under the black mottling?

[paulmic]

Yes, I had a go on it with some wire wool and there's nothing shiny underneath - just dark grey/black.

[Jim]

I personally wouldn't drink it - it's just not worth the risk.

However, I'd make pretty sure that there was a problem before I chucked it. Even stainless steel can get badly stained (paradoxically!) - there may be a way to make sure whether or not the metal under the staining is normal steel or stainless (google may assist there).

[Dads_Ale]

How did you sterilise the ball bearing? Several household cleaners, such as bleach, can corrode S/S and chrome.

[Pinto]

Possible you got a BZP mild steel bearing ?: I' d agree that its better to junk this brew too sadly

[keith1664]

Seeing as how you can buy chrome plated beer taps I'd be surprised if beer could dissolve it.

[paulmic]

Thanks folks for the replies so far.

Jim - I will try to find out what the metal is underneath, but I'm pretty sure it was chrome on top and that seems to have gone.
Dad's_Ale - I used Star San. The ball was smooth and shiny when it went in the bag so I don't think the steriliser caused the corrosion.
Pinto - I'm pretty sure it was chrome plated. If it was BZP - zinc plating - I guess that's just as worrying as you suggest.
Keith1664 - good point! I don't know what the answer is to that one, but I'll keep researching - not planning to ditch it just yet.

[Jim]

Nickel plate looks very similar to chrome plate but is cheaper. Maybe that's what you had?

[paulmic]

Pretty sure it was chrome but I'll certainly double check.

[millmaster]

I did something similar - used what I thought was a stainless steel bolt and a couple of nuts to weight down a bag of hops to dry hop. The bolt came out black as you describe ( so it wasnt stainless !! ) and the nuts came out as they went in, bright and shiny - so they were.

I just thought oh, well, wont use that bolt again and unlike you, I never even gave it a second thought and just drank the brew - I havent turned into a zombie ( yet ) or suffered anything I can detect ( over and above the advancing old age that is ) from drinking the brew.

I'm pretty sure that what ever it was, it wasnt chrome plated ( its the chrome in stainless that makes it stainless ) and would agree with the previous poster ( Pinto ) who suggested zinc plated/passivated and the zinc has been attacked.

Would I drink a brew where that had happened again - I honestly dont know - but I will probably use something glass as a weight next time. On the presumption in both our cases we used something zinc coated or plated ( its unlikely to be anything else because the coating is meant to protect the bolt/bearing from corrosion ) then actually people need trace amounts of zinc and also of iron.

Would there be more than a trace amount of zinc and iron in the brew - almost certainly.
Will the amount in the brew be harmful - I don't know, I don't appear to have suffered, but a high enough dose will be harmful
Some internet research from reliable sites would tell what is a high dose and what the associated risks are of high dosage of zinc or iron.

Dump the brew if you are worried about the risk. If you do decide to drink it, then dont drink it as a session ale, just have the odd pint now and again.

[Pinto]

Some reading for you. It seems that Zinc itself isnt too dodgy;

https://www.teck.com/DocumentViewer.asp ... talName=tc

Drawing attention to section 11....

"...Ingestion: Zinc is not expected to be harmful if ingested. When ingested in excessive quantities, zinc can irritate the stomach
resulting in nausea, vomiting, abdominal pain and diarrhea. Ingestion is not a typical route of occupational exposure..>"

Thing is - in an acidic wort, who knows what compounds it might have formed which arent so benign. I dont think I'd risk it personally.

For future brews, glass makes a much better alternative - especially where glass marbles are so cheap.

[millmaster]

Thanks for the link, Pinto, I did not appear to suffer any of the problems described so I probably didnt get a zinc overdose !
Definitely, I will be using glass weights next time !!

I think the consensus opinion here is don't take the risk, dump the brew

[paulmic]

Thanks for the info millmaster and Pinto, and for the link Pinto. Doesn't sound promising - as you say, not sure what's been formed after reacting with the acidic wort. Preparing myself to dump the brew - and will use marbles next time!

[weetabixface]

Zinc passivation layer will only be microns in thickness, concentration of zinc in your brew will be quite low,

for reference my bottle of multivitamins give me 15 mg per day of zinc

Perhaps worth considering before dumping your batch

W