[alt-photo] Re: casein image
pfriedrichsen at sympatico.ca
Mon Apr 4 12:14:20 GMT 2011
I did some experimentation with casein in the last couple of years so
I can add a little to this:
First off, I duplicated Alberto's results of the percentage of casein
by weight. I had read that it is 28% by weight of skim milk,
(specifically cows milk ) but when I dried it down after separation I
noted 23% of dried weight of skim powder which is the same value
noted by Alberto. Information I gathered about the viscosity is that
it varies by pH, temperature, type of caseinate salt, and of course
concentration. First, the viscosity goes up rapidly with
concentration; for instance, the viscosity increases almost 6 fold
going from 8% to 11% of sodium caseinate. If you want to delve into
this in more detail, try to find "Casein Viscosity Studies by Harper
F. Zoller. I found it some time ago freely on the internet.
What I enjoy about casein is its ability to hold such a high pigment
load without staining, when using such a low percentage of actual
casein in the emulsion vs gums 30-40%. I always wish to load more
casein into the emulsion for a stronger image but the viscosity will
go off the chats above about 12 % making it un-brushable. The best
for me is to work with it on the slightly acidic side where its
viscosity is less than when made alkaline but not too acidic of
course, because the emulsion starts to break down going below about
pH 5.5, based on my tests.
At 05:02 AM 04/04/2011, you wrote:
>>I was following Franklin Enos' formula,as much as I can deduce from
>There are three identical articles from Enos/Theisen notes:
>These notes explain how to prepare casein solution by adding ammonia
>to powdered milk curdled with acetic acid, and not straight from
>>... Lukas Werth uses an 8%, even thinner. It is difficult to deduce
>>percent solutions from the old recipes because they would pour
>>ammonia into milk or whatnot and then extract the whey, so who
>>knows how much the whey weighed.
>Lukas Werth's website www.lukaswerth.de is not online anymore, nor I
>have now at hand PF #6", but my notes say 0.8 g of dry casein plus
>10 cc of 9.5% ammonia. This is indeed about 8% or something less, if
>you take into account the volume of the casein. But this is not
>thinner than Enos/Thiesen formula.
>I tried to measure the yield from (my) powdered milk: it was 23% of
>dry casein. In addition, the apparent density of (my) powdered milk
>was 0.29 kg/dm3. So, to find the amount of dry pure casein used by
>those recipes that start from powdered milk, you have to multiply
>the volume (in metric units) by 0.29 and then by 0.23.
>This said, Enos/Franklin formula uses 1/4 cup (that is 2 fl.oz = 58
>cc) of powdered milk, and to the curdle you have to add 75 cc of ammonia.
>This means 58*.29*.23= 3.87 g of dry casein = less than 5% depending
>on how much water is in the curdle. And how much ammonia is in the
>supermarket bottle? 5%? 1%? In mine it is written "not more than
>9.5%". BTW, as a matter of fact, also pure water contains not more
>than 9.5% of ammonia!
>>The interesting thing is there is a difference in pH between sodium
>>and ammonium caseinate: sodium is 6.6-7.2, ammonium 5.7-6.7.
>It is not surprising, because at first it depends on the strength of
>the bases (NaOH or NH4OH) bonded to the casein. Then it depends on
>how much sodium hydroxide or borax has been used to dissolve the casein.
>>Alberto, if you would like me to bring you some ammonium caseinate
>>when I come to Italy, I can.
>I am (was) happy with my casein+ammonia solution, but I am ever
>curious so I will give it a try. In return, If you wish and we will
>have time, I may show you how to prepare a casein solution ready for
>use in about 15 minutes.
>>I traveled with some casein powder already and no questions were
>>asked, but my friend's husband's casein/whey protein powder for
>>drinking was confiscated so you never know. I thought since it was
>>in a baggie they might think it was cocaine.
>In 1990, I travelled Austrian/Switzerland/Italian borders with a
>fridge full of snow samples gathered for a study on Alpine
>pollution, and I had to declare that I was carrying "snow"... :-)
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