Glycin Keeping Properties
However they may be the only source for Glycin. Buy only enough of this chemical as you think you can use in a few months as it does not keep. Keep any used in a baggy in the frig.
I'll offer another data point here. My last purchase of glycin powder from The Photographer's Formulary was shipped by them to me on 5/19/2008. On 7/30/2010 I mixed my most recent 4-liter batch of Ansco 130 using most of the remaining powder from that batch.
That's a storage interval of 2-years 2½-months.
The resulting stock solution of print developer was, as near as I could tell without performing controlled tests, perfect. And the glycin powder appeared unchanged as well. It was the same very pale tan color I remembered when first opened. To the best of my knowledge and observation there was no degradation in the resulting Ansco 130 developer's performance.
From the date it was received the dry powder was stored in its original screw top plastic container. I further air-sealed that container by wrapping a single layer of plastic electrician's tape around the cap edge. The bottle remained in its light-tight black plastic bag while subsequently stored in my freezer.
When I needed some for mixing I would remove the bottle from the freezer and allow it to warm to room temperature before opening. I would then open, extract, close, and reseal the bottle, returning it to the freezer within an hour. This cycle was repeated four times using the current batch.
I have measured the temperature range in the freezer. It fluctuates between -5F/+5F (-21C/-15C), except during its brief defrost cycles when it rises to around 25+F (-4C).
This protocol has proved so successful that my next purchase of glycin will likely be a 1-pound (454 g) bottle. For the record, I did also save a small amount of the current glycin powder so I can compare it visually to the newly purchased powder, just to see if there is any slight difference in appearance.
And I seem to remember reading that The Photographer's Formulary is currently the only source for glycin. I read that they make it up by the batch something like every two weeks, or so. But I don't know how true this is. A quick email to them may be in order.
Since this data point involves the long-term keeping properties of a chemical substance, the standard 'YMMV' disclaimer is especially appropriate.
Ken
