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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => EQUIPMENT - Making Cheese => Topic started by: susanky on January 20, 2013, 06:05:32 PM

Title: Will brass affect milk?
Post by: susanky on January 20, 2013, 06:05:32 PM
I'm guessing it is not a good idea.  I won't bore you with the details of what I am trying to do.  But I needed a 1/2" 90 degree elbow make of some food grade material.  This plumbing piece fit perfectly.  The milk will come in contact with it (inside and out).  Does anyone know if this will affect my milk? (They didn't have stainless)
Susan
Title: Re: Will brass affect milk?
Post by: Al Lewis on January 20, 2013, 09:47:28 PM
Most brass contains lead.  Do not use it around food. 
Title: Re: Will brass affect milk?
Post by: bbracken677 on January 20, 2013, 11:27:50 PM
for real? I thought brass was a combo of nickel and copper...
Title: Re: Will brass affect milk?
Post by: Al Lewis on January 21, 2013, 01:13:33 AM
The composition of brass is normally made up of copper and zinc. More specifically it is usually 68.5% to 71.5% copper, .07% lead, .05% iron with the remaining ingredient being zinc.  Ornamental brass has much more lead in it.  That's why it shines so well and the polishing cloth turns black.  There are brass' without lead but without knowing exactly what the composition of the metal Susan has is it would be irresponsible to use it.  Typically aluminum bronze is used as a substitute for brass when you want to eliminate the lead.
Title: Re: Will brass affect milk?
Post by: MrsKK on January 21, 2013, 11:57:37 AM
Copper is reactive to the acids in milk, and so is aluminum, so I don't think she'd want to use either one...
Title: Re: Will brass affect milk?
Post by: susanky on January 21, 2013, 12:01:23 PM
Lead?  Really?  It is intended for water pipes in your home.  It doesn't seem like that would be allowed.
Susan
Title: Re: Will brass affect milk?
Post by: Al Lewis on January 21, 2013, 03:35:06 PM
Here's a link to an engineering site that lists the properties of materials.  There are 9 pages of different brass alloys.  You are welcome to peruse them all to find the one your fittings are made of to see if it contains lead. :D  You should also understand that comparing water to an acidic product is not really a good practice.  Seems a lot of folks over on the PVC thread do the same. ;D

http://www.matweb.com/search/QuickText.aspx?SearchText=brass (http://www.matweb.com/search/QuickText.aspx?SearchText=brass)
Title: Re: Will brass affect milk?
Post by: curd nerd on January 21, 2013, 04:01:41 PM
dear SUSAN,,,,,,,,,please do not use BRASS,,,,,,,,,,,i make this "bold" statement as i have a Ph.D in both organic chemistry

and chemical engineering..please listen to AL LEWIS.............i'm sure you can find  a S.S. fitting

many regards ,,,,,,,,,brian
Title: Re: Will brass affect milk?
Post by: susanky on January 22, 2013, 02:31:27 AM
I am not going to use it.  But am just trying to understand.  Difference in acidity makes sense.  Though I don't exactly know why  :-[  I'm sure I will be able to track down something stainless steel with a little effort.  Thanks for all of your comments.
Susan
Title: Re: Will brass affect milk?
Post by: Tomer1 on January 23, 2013, 10:00:12 AM
Look in winemaking and beermaking shops servicing the proffesional industry, they will likely have it or will be able to get it for it and ship it by mail.
Title: Re: Will brass affect milk?
Post by: susanky on January 25, 2013, 01:48:01 AM
OK well now I looked more closely at the packaging.  Did I assume it was brass?  Or maybe the salesperson told me it was.  But now I see it is copper.  So that makes a little more sense with the brass/lead issue.  This is not brass.  Sorry!  But is copper any better?  I know if you whip egg whites in copper you don't have to add the cream of tartar..... :D
Susan
Title: Re: Will brass affect milk?
Post by: MrsKK on January 25, 2013, 01:32:10 PM
Copper reacts to the acids in milk, too.  Not a good idea, as it may affect curd set, etc.
Title: Re: Will brass affect milk?
Post by: Al Lewis on January 25, 2013, 03:14:03 PM
I thought they made Emmentaler and Gruyere in copper pots.
Title: Re: Will brass affect milk?
Post by: Sailor Con Queso on January 25, 2013, 04:58:33 PM
Lots of Europeans use copper vats, but generally not allowed in the USA.
Title: Re: Will brass affect milk?
Post by: Alpkäserei on January 30, 2013, 02:28:58 AM
Copper reacts to the acids in milk, this is a half truth.

What we have is this:

Clean copper does not pose any problems. This would only react with milk at boiling temperatures and even then I am skeptical of the supposed dangers because we make Ziger in the copper vats, which is made by heating the whey to near boiling and coagulating with lactic acid (like ricotta)

When copper is dangerous is when it is tarnished. It is the dull brown tarnish that will react with the acids in the milk.

More specifically, (as I understand it) Copper will oxidize into tarnish, which is a dull brown (which can further oxidize into green verdigris later) The acids in milk will react with copper oxide (I don't know which copper oxide it is specifically) What is bad is when the sulfur compounds react with the oxides and form copper sulfates which are extremely toxic (they treat lumber with it)

European cheeses are traditionally made in copper vats, all Swiss cheeses are made in copper and most AOC's in the country state that only copper can be used. Cheese WILL NOT taste the same out of stainless steel. I don't know why, I don't care if it makes no sense chemically or biologically, I know that it is true.

I don't have a PhD to back up my claim, just thousands of years of traditional experience which I trust far beyond what any words of science will tell me, because it has proven itself to be true.

So with copper in cheese, it is important that we keep the copper shiny and copper-colored, not dull or green at all or it can create poisons.

When it comes to piping, we have to consider that it is not practical to clean the inside of a pipe fitting every time you use it. It will get heavily tarnished. In water, this is no problem and it may not be a problem in milk, but I would say avoid it. The only exception would be if you flush it out with strong vinegar or lactic acid after each use, and then cleanse through with water without letting in air between them

Actually, my advice would be to avoid pipes altogether, to me this is just asking for contamination either of bacteria or from cleansing agents.

Many US States do in fact allow copper vats, if you can prove that it is important to the process somehow. For example, it is often allowed (that is, you are excepted from the general rule) if you can prove that a copper vat is an important part of the traditional process, then you have to prove that you can keep it clean and safe. For example, many stateswill let you use copper vats to produce Swiss Cheese or Gruyere, because it is an important part of the tradition. But you won't be so lucky if you are making cheddar or bleu.
Title: Re: Will brass affect milk?
Post by: Al Lewis on January 30, 2013, 03:30:37 AM
Hopefully that is not a pre-soldered water fixture as the solder may have lead in it.
Title: Re: Will brass affect milk?
Post by: Alpkäserei on January 30, 2013, 05:03:12 AM
plumbing solder is lead free,
tin, silver, copper and bismuth
Title: Re: Will brass affect milk?
Post by: curd nerd on January 31, 2013, 02:20:07 AM
dear ALPKASEREI,,,,,,,,,thankyou for such a comprehensive post, spent my working life in whisky distilling and other

spiritous beverages industry and consequently have a deep respect for copper for the reasons you gave plus the following

it assists in the removal of sulfides............dissapates heat readily.........inhibits liquid borne micro-organisms such as

bacteria , viruses , algae and parasites through it's anti-microbial properties / effects

E-Coli can only live on copper for a couple of hours even when the surface is dry but can "party on" , on stainless steel for

months

i'm sure you are aware of only using cadnium free solder  around food equipment too [ just saw your last

post come in ] 

last but certainly not least copper is very easy in the eye department

many regards,,,,,,,,,,brian