Re: conservation of albumen
Hi Alberto, see this:
"...The albumen solution will remain useful for several weeks after the
one-week aging period. The smell of the albumen and its color,
sedimentation, etc., will reveal when it has decomposed too badly to
Also in the same page (located slightly above the first quotation):
"...Beating the albumen is necessary to accomplish the task of chemically
breaking down the different protein substances until a more or less
uniform substance is created. While beating to a froth does the major work
of evening out the viscosity of albumen's different components, further
'denaturation' by chemical means must take place before the albumen is
ready to apply to the paper. The chlorides added are vital to the
formation of the photographic image, but they also help to denature the
albumen; one of the effects of adding chlorides is to reduce the volume of
froth produced during the beating step. The third kind of denaturing
treatment usually employed is the adjustment of pH by the addition of
acids or alcohol. The chemical forces which bind together the enormous
molecules of protein grow weaker as the pH is lowered, and the physical
properties of the substance change as a result. The effect of adding
chlorides and acids, such as acetic acid, and finally beating the egg
white is to completely and irreversibly change it. After settling for 24
hours and aging in a refrigerator for one week it is a yellowish
homogeneous liquid with a slight 'aged' odor that signals its readiness
So, there's no other information about denaturation and long term storage
of albumen solution (as I can see/find) in the monograph.
Why not mixing in batches, just enough to coat the needed amount of
sheets? (Like say... 40 11x16" - quarter size - sheets at a time.)
Albumenized papers can be stored for much longer than a year...
18 Ocak 2009, Pazar, 10:34 pm tarihinde, Alberto Novo yazmış:
> What do you suggest for the long-term conservation of albumen solution
> at least one year)?
> Adding a preservative (thymol, sodium azide, ...)? Simple storage in a
> sealed jar? Sealed and refrigerated at 4°C? Freezing?