use-by date?

[Steve Mack]

Thank you all who replied to my question about one-shot developers.

I have another question: what is the absolute maximum time (if there is such a thing) that I can keep a developer solution after it is mixed up?

To avoid risk of over-age developer,, I mix up a batch when I have 6-8 rolls of B/W film to process, and then make a long evening of it. I can't reliably predict when I'll have a roll of film done and ready to process, but it would help it I could have some idea of the keeping qualities of developers after they've been mixed and bottled.

What has been your experience?

Thank you to all who reply.

With best regards,

Stephen

BTW, over-age developer really stinks, at least the Ilford variety did, which was a good indicator that it really wasn't usable for film processing.

 

[brofkand]

Depends on the developer and storage techniques. Let's assume you're talking about a gallon of D-76/ ID11 and at room temperature.

If you store it in a gallon milk jug, maybe 4-6 months. The lid doesn't close very tightly, so air can get in.

In a special black chemistry jug, 8-10 months. As long as you squeeze as much air out as possible.

I've heard tales that keeping chemistry in stoppered brown glass bottles (with marbles thrown in to keep the liquid level up to the stopper) lasting indefinitely. Glass is not permeable. Even darkroom black jugs "breathe."

Those times are just guidelines. If you're worried your developer may be bad, just pour some in a dish and drop a film leader in. It should develop out to max black. If not, throw it out.

 

[Mike Wilde]

Vigorously boil distilled water, in the kitchen in a stainless steel pan, or kettle dedicated for the purpose, and then let it cool. It drives off any dissolved oxygen the otherwise usually is dissived in it. This will help stock developers last longer. Also try not to whip too much air into the liquid when dissolving the dry chemistry in.

Top of with nitrogen or propane or butuane or private preserve wine preservative to keep atmospheric gas off of the top of the liquid is another step you can take. I usally hold the last step for colour developers that are a financial investment, compared to any HQ developer. The other option is to reuse foil wine bladders if (ofthe poor) wine is sold by the box where you live.

 

[srs5694]

I'd like to emphasize part of brofkand's response: "Depends on the developer." Some developers, such as Rodinal, are legendary for their keeping properties. Undiluted Rodinal can keep for years, perhaps decades. Most powdered developers (D-76, XTOL, etc.) last for a few months to perhaps a year or two. A few last for much shorter periods, but I don't have any examples to name off the top of my head.

This assumes you're storing a stock solution. Once you dilute the stock for use, you should use it immediately. Working-strength developers seldom last more than a few days, and some only last an hour or two.