Dev. stock solution in fridge?

[MurrayMinchin]

This should be a quickie...

Does keeping paper developer stock solution (in an airtight container filled to the top) in the fridge extend its life?

Murray

[gainer]

This should be a quickie...

Does keeping paper developer stock solution (in an airtight container filled to the top) in the fridge extend its life?

Murray

It may cause precipitation of some of the ingredients. What developer are you concerned about?

[Dave Miller]

This should be a quickie...

Does keeping paper developer stock solution (in an airtight container filled to the top) in the fridge extend its life?

Murray

No.
Is that quick enough?

[MurrayMinchin]

Hi gainer,

I use a variation of Ansco 120 that I call 12/15 because it has 12 grams of metol and 15 grams of glycin in it. I order 50 grams of glycin at a time which gives 4 litres [oops...edit...make that 3 litres] of stock solution. I test for print development times using the emergence time of the negatives clear edge at a standard contrast setting, aperture, and exposure time, to which I multiply by a factor of 4.5. Normally, at 72 degrees the fresh developer emergence time is 40 seconds and gradually increases to 48 seconds where it stabilizes for quite a while, then I toss it when it gets to 50 seconds. (With Life and its complications and my sporatic appearances in the darkroom, this can take several months). This last batch mixed from 9 month old stock solution went from a 40 to a 48 second emergence time faster than what I'm used to, which caused me to wonder if keeping it in the fridge would extend its life.

Murray

[MurrayMinchin]

No.
Is that quick enough?

Yup

Murray

[Dave Miller]

Yup

Murray

To expand a little of my previous reply; just a little . I believe the key to developer solution longlevity is keeping the oxygen out of the solution rather than temperature control. I top up my developer bottles with gas, and keep them at around 20 deg C. Working solutions keep for a week or so, whilst undiluted stock is good for many months.

[Gerald Koch]

It's best not to put developers in the refrigerator since this can cause some ingredients to crystalize out of solution. It can be very difficult to get them back in solution. There is only one commercial developer I know of that recommends doing so and this is Ethol T.E.C.

The worst enemy is oxygen which is why developers should be stored in only certain plastic bottles or preferably in glass. The container is more important than the storage tmeperature.

[MurrayMinchin]

Thanks Gerald.

Murray

[avandesande]

Rule of thumb is that chemical reactions double every 10 degrees celsius of an increase in temperature. This would include the reaction with oxygen. Take a little bit of your developer and refrigerate it, if it doesn't come out of solution you can store it this way.

[Kirk Keyes]

I would say "no" on the basis of chemical safety - you don't want most developer chemicals to be stored where they may come in contact with food. If you have a separate, dedicated refrigerator which will only be used for chemical storage, and everyone in the house understands this, then I would say "yes".