will metal and other contaminants be removed during fermenting and racking

[Brad Haugen]

Hello, I screwed up by cheeping out.
I live in rural Alberta and bought a new 3 gallon galvanized chicken feeder.
Drilled it full of holes and put a 1 inch treaded rod in the center, cut two half moon boards and built a really cool apple press that fit onto the fermentor bucket so that the juice drained into it. Well after about 15-20 uses it seems the galvanized zinc coating was being removed by the acid in the apples. Now It seems I have about 50L of wine that may be contaminated with zinc.

My question;
Can or will the zinc be removed through the normal process of fermenting and racking?
Is there some way to remove the zinc from wine? (I have read what water plants do)
Am I going to have to run it all through the still to remove it and do you think that will even work.
I have a small 1 gal pot still but could borrow a 5 gal T-500 but have never run one.
Thanks in advance for your help and other comments :-(

 

[Vale71]

Zinc is a yeast nutrient but in trace amounts. The concentration you have in your wine is probably so high that even the yeast will be negatively affected. In any case most of it will still be in the wine at the end of fermentation so that's no help at all.
I presume distillation will remove all non-volatile compounds including zinc salts but as I don't really know much about distilling spirits (other than that it can be very dangerous and I don't mean just because of the fire hazard) I can't give you any specific advice.

 

[dwhite60]

Sure you don't want to hear it but, I wouldn't drink it.

All the Best,
D. White

 

[IslandLizard]

I've moved your thread to the Cider forum. Hopefully you'll get advice from the experts here.

BTW, apples make cider, not wine.

 

[AzOr]

I dunno. However your press sounds really cool. Minus the zinc contamination of course.


Can you post a pic?

 

[MaxStout]

Sure you don't want to hear it but, I wouldn't drink it.

All the Best,
D. White

And even if I was bold enough to drink it myself, I still wouldn't serve it to others.

It's not worth the risk. Dump the batch and use food-safe materials going forward.

 

[dwhite60]

If that chicken feeder was made in China there is no telling what else (cadmium) was alloyed in with the zinc.

All the Best,
D. White

 

[IslandLizard]

50L of wine that may be contaminated with zinc...

...and whatever else was in that galvanized coating.

 

[Yooper]

That sucks. It's a dumper I'm afraid.

 

[AzOr]

RIP

 

[gregbathurst]

Plastic, glass or stainless steel only, unless it is well painted.

 

[RPh_Guy]

How about some science?

Let's take a stab in the dark at how much zinc was dissolved. Let's say 5 grams, that's the weight of two pennies. To me that seems like a conservative over-estimate, without having seen the source.

I don't know how much you drink. You used the word "wine", so let's base your consumption habits on that.
So, perhaps you drink 2 glasses of wine (12oz total) per day, that's 355mL.

5000mg in 50,000mL times 355mL gives 35.5mg.

So if you drink 2 glasses per day, based on my assumed amount of zinc the theoretical maximum is 35.5mg/day.
The "Tolerable Upper Intake Level" suggested for zinc is 40mg/day, which is designed to provide a good safety margin for chronic exposure. Zinc is excreted, so you'd have to consume more than 40mg/day total zinc every day for months-years to potentially develop mild toxicity.
Source:
https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/

Of note, one large study gave participants zinc 80mg/day for 6+ years, with only minimal increase in adverse effects. These participants were all age 55+.

Also, yes, the yeast and other microbes certainly would have taken up a significant amount of the zinc. It's a necessary nutrient for them, just like it is for us. Therefore much of the zinc content would have been removed by racking. It's also probable that fining agents would remove zinc compounds, to at least some extent. I'm not sure this has been studied.

In my opinion, this cider is safe to consume in moderation.... Just like any alcoholic beverage.
The amount of zinc needed for acute toxicity is much higher than would be in a 750mL bottle. The only reported case of acute toxicity was from consuming 570mg (0.57g) of zinc, which resulted in vomiting.

Distillation certainly would leave behind all the metals, if that's something you're considering.

Obviously, time for a new press, one that doesn't dissolve.

Cheers

 

[S-Met]

I overlooked this important phrase:

Well after about 15-20 uses it seems the galvanized zinc coating was being removed by the acid in the apples.

What does 15-20 uses mean? 15-20 pressings in a single day, or do you mean this is 15-20th batch of 50 liters of wine?

Assuming the above phrase means batch and coupling with what @RPh_Guy informed us above, I would speculate that the estimated 5 grams of zinc may need to be reduced by the number of approximate uses. (5gram zinc/15 uses).

If this is your 15th batch, this is perfectly safe.

 

[dwhite60]

You'd really have to have a starting and current weight of this feeder to know how much zinc has been dissolved. As it is zinc and Chinese zinc at that, I couldn't trust it.

Some batches you pressed may have had higher acidity and therefore have a higher zinc content that others.

All the Best,
D. White

 

[IslandLizard]

Since it's only a 3 gallon bin, he can only crush a very limited amount of apples at a time. It's safe to assume he combined the 15-20 batches of crushed apples to obtain his 50 liters.

I'm surprised how fast the galvanization wore off/dissolved, though.
It's definitely the wrong piece of equipment for the job.

 

[RPh_Guy]

One more thing!

Sensory detection of high zinc levels:

Some people can detect zinc at 3mg/L, well below even chronically toxic. Even at this level, zinc gives an undesirable astringent taste.
The solution tends to be opalescent. You can see the metal.
Also, it develops a greasy film when boiled.

Source: World Health Organization

I hope I've painted a clear enough picture that this cider won't be a health risk.
Cheers

Lol @ "Chinese zinc".

 

[ten80]

How about some science?

Indeed, let's not recommend dumping the cider based on knee-jerk "gut feeling" paranoia.

Obviously, time for a new press, one that doesn't dissolve. Cheers

AMEN!

One thing to consider is that yeast will uptake and bind yeast, thereby reducing zinc concentrations in cider/beer/mead/etc. Additionally, an excess of zinc will inhibit or kill yeast, as suggested by the following sources:

"Zinc is an important co-factor in many enzymes and thus a requirement for yeast growth. Most yeast strains require 0.1 – 0.2 mg/l of zinc. Zinc levels greater than 0.6 mg/l can inhibit yeast growth (Priest, Handbook of Brewing)."

"The consensus of such studies is that, although zinc interactions are yeast strain-dependent, concentrations around 0.25–0.50 μg/mL appear to be optimal for cell growth, and 1–2 μg/mL for glycolysis"

Based on this, the cider is safe if you had a strong, complete, normal fermentation. A partial/slow/unealthy fermentation may occur the zinc levels were >0.6 mg/L. Even 0.6 mg/L would be safe according to the 40 mg/day dosing referenced by RPH.