Quote Originally Posted by heterolysis View Post
The colder it's kept, the longer the shelf life, theoretically.


Are you talking about powders or liquids?

Liquids will benefit greatly from being kept cold. Powders it won't make much of a difference. Liquids in a fridge will be roughly 20C below room temperature and should theoretically last 2^2= 4 times as long as their listed shelf life, if they have one. And this is probably a gross underestimate of it, since they live longer than shelf life to begin with.

Vacuum sealed powders will probably last forever.
Liquids. I seem to recall from college chem courses that chemical activity roughly doubles with each 10 C rise in temperature. This would suggest that each comparable drop in temp would halve deterioration, although enough drop might precipitate components which might then be difficult to redisolve. So, with the proper temperature for a fridge being perhaps 35 F what will precipitate out, and can it be re-dissolved? Any experience out there? I know that some formulae for developers specify the temperature of the solute and the order of addition of components; this suggests that cooling below STP might be deleterious.... Any photo chemists out there who might weigh in?