whats causing this

[Uncle Harley]

That's why I don't eat beef and switched to wild game  LOL

[coonhollow]

I'm putting my money on the anti-caking agent (yellow prussiate of soda).

http://en.wikipedia.org/wiki/Prussian_blue

Hope you're not generating Hydrogen Cyanide fumes.

you have the wrong chemical composition!
http://en.wikipedia.org/wiki/Sodium_ferrocyanide

[edit] Uses
As yellow prussiate of soda, it is added to road and food grade salt as an anticaking agent.[2] When combined with iron, it converts to a deep blue pigment, which is the main component of prussian blue.[3] In photography, it is used for bleaching, toning, and fixing. It is used as a stabilizer for the coating on welding rods. In the petroleum industry, it is used for removal of mercaptans


I would say your culpret is iron!

[misanoel]

Yes, iron reacts with sodium cyanide to produce sodium ferrocyanide (aka prussian blue).  What concerns me is that prussian blue reacts with strong acid to produce HCN  (per Wikipedia entry quoted below):

"Despite the presence of the cyanide ion, Prussian blue is not especially toxic because the cyanide groups are tightly bound. Other cyanometalates are similarly stable with low toxicity. Treatment with acids, however, can liberate hydrogen cyanide which is extremely toxic, as discussed in the article on cyanide."

Just to be safe, I'd switch to a salt that doesn't contain cyanide compounds of any sort.

[ljones]

 by golly coonhollow i think you have it , when i salt my skins i usually lay them on my shop floor and there could very well be some iron filings on the floor from where i have been using a cut off wheel to cut the wire mesh i use on bases

[misanoel]

Sorry, I should have said that sodium ferrocyanide is yellow prussiate of soda.  Ferric ferrocyanide is prussian blue.  Either one reacts with strong acid to generate HCN.

[coonhollow]

try to keep any mineral away from your tanning process. I got this years ago from weighing down skins with a piece of puck board that had a eye bolt through it.. the eye bolt was the culpret!

[cyclone]

Give this a try....

Take a small jar of your pickle solution, a clear jar so that you can take pictures...
Sweep up some of your iron filings and put them into the jar as well.
Don't get too excited if you don't see a color change at first but let the filings settle to the bottom.  Take pictures....
Let set several hours or overnight and see what happens..

Lightly stir or swirl the solution ...taking pictures to show us any reactions..


Try repeating the experiment only using copper filings...taking lots of pictures..

[Tom King]

Change salt.............
I used that feed salt when they didnt have the regular salt I used...........
Mine had a blue tint but not as bad as yours in the KT mix........
Use meat cureing salt...........fine grade.........

[coonhollow]

I think no matter what salt you choose it will still have "yellow prussiate of soda" it there for one reason only. so your salt isnt a hardened mass in a bag! we have 2 salt mines here and even table salt contains it..different levels for some. you should get granular "mixing salt" and not what is considered "feed salt"

[misanoel]

I have three 4-lb boxes of Morton brand of canning salt, labeled as "plain salt--nothing added.  For corning, canning and pickling."  It's available both as coarse crystals and as finer ones (similar to table salt).  After several years of storage in the kitchen, it hasn't yet congealed into unmanageable blocks, though it might in a more humid setting.

[Steve W]

Ljones,
I to have had this on some of my capes, don't know what's causing it? I use Krowtann also. I only notice it on capes that are prepped and shaved on the flesher. When I get the capes out to mount is when I notice these blue streaks on the skin side of the freshly thawed cape. Go figure!
Steve

[Steve W]

Just thinking, I wonder if the cape is getting some metal dust off of the blade or sharpening steel that would react with any acid still left after neutralizing? Mine seem to be straight line streaks of blue randomly across the cape.
Just a thought! Steve

[misanoel]

Unpurified well-water can contain iron, too.

[cyclone]

Really hard to say what the coloration is from...

The salt you have pictured there is no more than granulated rock salt...


http://www.unitedsalt.com/site/html/p_0022.htm

USC Ranch House Feed Mix rock salt is a money saving value when calcium and/or sulfur feed supplements are desired in addition to salt. The rock salt continues to be mined from natural deposits 1,500 feet below the earth's surface, as it has since the late 1920's. The salt is crushed and screened for the specific gradation suited for livestock and poultry feeds. An anti-caking agent, YPS, is added to prevent caking and lumping, ease handling, and maintain flow ability.

That being said, I'd go to a better grade of salt.

I'd be curious to know your exact pickle recipe and if anything concerning it  has changed recently..

Don't rule out your plastic vat either..empty it and wipe the sides down with a white towel, see if you pick up any color..it can bleed out of plastics and black plastic will have quite a few colors mixed..

[coonhollow]

I have three 4-lb boxes of Morton brand of canning salt, labeled as "plain salt--nothing added.  For corning, canning and pickling."  It's available both as coarse crystals and as finer ones (similar to table salt).  After several years of storage in the kitchen, it hasn't yet congealed into unmanageable blocks, though it might in a more humid setting.

canning salt would be quite pricey for a comercial shop!