[alt-photo] Re: casein

[Peter Friedrichsen]

I can confirm that some time ago I also measured 
exactly 23% by weight of ammonium caseinate 
precipitated from skim milk using vinegar. 
I  measured out 1 ml my casein emulsion, then 
dried it in an oven at about 50 C for about an 
hour, then weighed it on a scale that measures 
down to 0.001 g to get the percentage solution 
strength, and then scaled this up based on the 
total volume of the casein emulsion and finally 
comparing that to the starting weight of the milk powder.

Peter Friedrichsen


At 02:03 PM 13/06/2012, you wrote:
>Hi Chris,
>about making homemade casein, I tried this some 
>years ago when I began experimenting casein printing.
>My first approach had been preparing casein from 
>powdered milk, finding a dry casein yield of 23% 
>by weight. I don't know if changing powdered milk the yield may be different.
> From the yield, I calculated that Franklin 
> Enos/Ernest Theisen recipe is equivalento to 
> about 5% solution of casein, while Bob Schramm 
> (www.usask.ca/lists/alt-photo-process/alt95/0831.html 
> if still there...) cited by Laura Blacklow in 
> Alternativephotography.com is 4%, and that in "Spirit of Salts" is 10%.
>In Italy we have not cottage cheese and use 
>ricotta instead. But ricotta is not casein, 
>being made warming the whey up to 90°C, and 
>lightly acidifying it (ricotta means "cooked two 
>times") so that albumin and globulin denaturate 
>and become insoluble. So, I did not investigate 
>about a potential "ricotta printing" :-)
>For me, powdered milk was not easy to buy, and 
>fresh low-fat industrial cheese (a possible 
>substitute of cottage cheese) are often treated 
>with lactic or citric acid, alginate and cream. 
>Finally I ended using dry casein in order to 
>avoid all my problems of supplying and purity.
>BTW, I am still without my darkroom, so that I 
>have not yet had the opportunity to give a try to your ammonium caseinate.
>Alberto
>www.grupponamias.com
>www.alternativephotography.com/wp/photographers/rodolfo-namias-group
>
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