Will D-76/ID-11 increase in activity as it ages?

I have a full half gallon of ID-11 stock solution that was mixed almost a year ago. It was mixed using distilled water using a temperature controlled magnetic stirrer. Filled to the brim, no air space in a brown "Plastic" photo chemistry bottle.
Now almost one year later, I decide to use it, as I have used up the previous half gallon. Visual inspection shows it to be very clear in color, perhaps a slight tint of pinkish purple. I then proceeded to develop some exposed test snips of Plus-X in stock solution, another with Plus-X in 1:1, then Ilford Pan F stock solution and Pan F 1:1. O my Gosh, they looked like they were processed in hot D-72 or D-19, talk about soot and chalk. Very contrasty, No not quite Kodalith ortho type contrast. And yes they are printable, but very dense and contrasty.
QUESTION: Can D-76/ID-11 increase in activity or perhaps alkalinity with age?? I always thought that developer lost its activity as it aged NOT increased.
I'd bet I could cut 1 1/2 minutes off the development time before I'd get a normal density.
I've never heard of such as this. Has anyone else had this experience with D-76 or ID-11??
With thanks,
Sam Hotton

I'm surprised to hear that the developer is still very active. I've read reports that D-76 will increase in activity for the first 24 hours after it is mixed up. After that, the activity level drops to what's considered normal and remains stable over the long term. To see an increase in activity over the very long term as you've described is not very likely. It is more likely that you've overdeveloped your film. Perhaps your thermometer reads low, or you got the times wrong.

It is a well known fact that D-76 increases in "contrast" as it ages, regardless of use. Since ID-11 is in essence a clone of D-76 I think the same would apply.

Dear Sam,

Amazingly, the pH (and hence the activity) of unbuffered D-76 cycles up and down; or so I am told by people who should know, though I have never verified it. From what I understand, though, the effects are not as great as what you describe. Also, I am pretty sure that ID-11 is buffered. Some D-76 is; some isn't; it apparently depends on where you buy it. At least that is what Ilford found when they tested it a few years ago.

Cheers,

R.

I have had ID-11 in a full fizzy-pop bottle kept in darkness (a rarely opened cupboard) for 14 months with no detectable deterioration or colour change: still as clear as the day it went in. I didn't put a densitometer or suchlike on it but I'm sure there must have been some change, but it was not detectable to my untutored eye.

I'm not sure that ID-11 and D76 are still as similar as they used to be: certainly IIRC, some film's recommended times are quite different in Ilford's datasheets.

Cheers, Bob.

Published formula D-76 (and ID-11) can undergo fluctuation of developer activity. This is due to partial oxidation of hydroquinone raising the pH by a small degree, and it can be prevented by better buffering agents or increase of borate content, but it is unnecessary if the developer is used rather fresh. (If hydroquinone is left out int from D-76 and pH is adjusted to 8.5 to 8.6 range, the pH won't rise but just drop gradually.) The increase in activity (contrast) is usually small, but when hydroquinone is oxidized to such a degree, sulfite is also oxidized and less amount of effective sulfite is in the solution (but not to the degree to affect superadditivity), so expect change in granularity as well. People who use D-76 stock strength with 400 speed films often notice that they get best image quality when the developer is absolutely fresh. Both the pH and sulfite are involved.

toss it, and other unsolicited advices

Developer is so cheap, why bother and worry whether your next, important, roll of film is going to survive an unpredictably active, year-old batch of developer?

It sounds like your film developing is, like mine, an intermittent activity, with bursts of processing separated by long periods of fallow time. This pattern suggests that, like I have, you should switch to developers with long shelf lives. I use PC-TEA and 510-Pyro, which are cheap and easy to mix and last forever on the shelf.

Alternatively, you could purchase the bulk chemicals for mixing D-76/ID-11 and make each batch up fresh just before you use it.

Mixing your own is easy, cheap, and the best way to ensure that each batch you use is fresh and ready to go.