Author Topic: Copper Kettle issue / Parm  (Read 85 times)

Offline Sir Loin

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Copper Kettle issue / Parm
« on: September 10, 2014, 02:55:13 PM »
So, this is my first post, been making cheese for a while.  Today I made my first parm, and also for the first time I used an old copper kettle that I have. The kettle is BIG and OLD as you can see from the pictures below.  Yesterday I cleaned it thoroughly with a vinegar and salt solution and this morning I washed it with hot water and also disinfected it with a standard bleach solution.  There is no getting all of the patina off of this pot, and if it ever had a tin or nickel coating on it, its not there any longer.  My 8 gal. parm make went well except ... the cheese has an ever-so-slight green tint, obviously from the copper.  After some googling, I convinced myself not to worry too much about copper toxicity (or should I be?) because the curd was pulled from the kettle at a PH of 6.3 which should not be acidic enough to react with the copper too much.   Unless the consensus is that this should go in the dust bin, does anyone have advise on how to get the rind to 'overcome' the green tint?  Normally, I would not do anything to a parm rind except salt and maybe oil.  But in my head, this is a cosmetic issue.  I added 9 drops of annatto into this make, so I am thinking that after long aging the inside might obtain the right hue ...  Also, this might come out of the brine looking just fine ... I am always amazed at these albino looking cheeses that somehow look yellow a few weeks later.  Thanks for any help and cheers all!


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Offline ArnaudForestier

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Re: Copper Kettle issue / Parm
« Reply #1 on: September 10, 2014, 05:35:41 PM »
Unequivocally, I would not eat this.  Green in copper is verdigris, your pot has it extensively, and that is absolutely poisonous.  I could be wrong, but I believe that's what you've got going and it's not simply copper leaching into your curds (in which case, you'd pick up some copper - still not great, especially over time, but at least it's not poisonous like verdigris).  Forgetting even this - the old adage If in Doubt, Throw it Out is a good one. 

Strongly suggest you toss this wheel and thoroughly clean the pot.  Sorry, man.
« Last Edit: September 10, 2014, 06:16:25 PM by ArnaudForestier »
- Paul

Offline Sir Loin

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Re: Copper Kettle issue / Parm
« Reply #2 on: September 10, 2014, 06:49:19 PM »
Thanks! I can see you are correct and I think I was engaged in a bit of wishful thinking.  I just finished tearing it in half and tossing it.  But I think I learned something about PH at pressing.  After tearing it in half, I noticed that the PH at the surface and side of the cheese was significantly lower (about .15 lower) than in the middle of the cheese.   I could never figure out what to measure at pressing, the cheese or the whey.  So, I think the whey is closer and probably will let it overshoot a bit in the future.  Cheers,   

Offline ArnaudForestier

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Re: Copper Kettle issue / Parm
« Reply #3 on: September 10, 2014, 07:07:35 PM »
I actually do both, typically.  I'll take a small sample of curds from the vat, say, 1/4 cup, and try to keep it under the same conditions as my pressing curd.  Not an ideal measure, but pretty close (I have some leeway, given all I do are alpines).  I also measure whey.  Whey is going to be a bit higher.  Can't recall exactly, but I believe Pav might have said, by +.02 or .03.  Don't quote me. 

Good luck!
- Paul