Kodak D76 Expiratiotion Date: Mix By or Use By?

I have an unopened Kodak D76 1 Gallon powder sachet, with a 10/2015 expiration date. Am I supposed to mix it by the expiration date, and presumably still have about 6 months to use the properly stored stock solution? Or am I supposed to use it all by next month? I realize it will likely work fairly well either way, but if it will produce slightly suboptimal results one way then I would rather buy new. Developer is cheap.

It does not last very long once it is mixed. That is the expiration date of the powder.

It should b good for far, far after that expiration date as long as it hasn't been opened or exposed to high heat. Once it was mixed up, I never managed to get more than 3 to 6 weeks out of it before the PH would build up and it would start to cause more grain. If I'm using this developer, I usually buy the small 1 qt size packets due to this issue, or save up my rolls until there's enough to use up the 1 gallon of developer.

All of which is why I switched to TD-16 from Photographers' Formulary, a very similar developer that gave me 4 months or more of storage w/o issues. Not everyone seems to have this issue w/ D76, but it's a well documentation problem, and I certainly experienced inconsistent results after the storage times that were mentioned.

http://stores.photoformulary.com/td-16-improved-d-76/

The powder (in Kodak bags) seems to last forever. I have tried the last one I had a year ago and it was already 5 years old. It worked perfectly.
Now I get the chemicals and mix D76 and D23 by my own. D23 even diluted lasts considerably longer and gives consistent results all the way till the end.

Everyone experiences will be different, I'm sure. For the last 10 years I've been working on a lot of d-76 that was manufactured in Sept 1963. No use-by date. Of course, it is seal in cans, and the packaging has been very important to it's longevity. In ten years when I finish this lot, I expect it will still be good. I have mixed d-76 (cans and modern packaging) and seen it last 6 months in a well-sealed plastic bottle. And that's stored in a garage where extreme temperatures fluctuate summer to winter. I don't do testing as long as the negatives are good. The old paper/foil packages are perty bad. I have had about 50/50 luck with those.

I'd mix it ebfore the end of the year and use it fairly rapidly. You don't risk anything really.

I'm about to do a contact-sheets session with some Eukobrom that is black and I'm confident I'll get good results.

Does anyone know what happens to D-76/ID11 once it is mixed in liquid form, technically speaking? Presumably oxidation occurs, but what does this mean visually?

I can tell you what exhausted d-76 "doesn't do". It doesn't develop your negatives to the expected contrast within the recommended time. You can expect weak, under-developed negatives. I would expect the same results from developer that has been left in the open for an extended period, ie; allowed to oxidize. I want to say that the color of oxidized developer is brown. Similar to Dektol. I have some in powdered form, that is in that condition. I'll try and post an image. I may have saved those negatives also. If so, I'll post an image of that also.

I suspect an unopened bag to last way beyong the expiration date. Once mixed, it is a different story but it is not that critical as we often read . I prepared some D76 earlier this year and even after 6 months, my bottles of stock solution are still crystal clear, no color.

DannL. said:

I can tell you what exhausted d-76 "doesn't do". It doesn't develop your negatives to the expected contrast within the recommended time. You can expect weak, under-developed negatives. I would expect the same results from developer that has been left in the open for an extended period, ie; allowed to oxidize. I want to say that the color of oxidized developer is brown. Similar to Dektol. I have some in powdered form, that is in that condition. I'll try and post an image. I may have saved those negatives also. If so, I'll post an image of that also.

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Thanks. I recently put a roll of Tri-X through some ID11 I mixed almost two years before, and the results were better than anticipated. As I tend to use lower speed films in Rodinal, the ID11 oxidises before it gets used.

I think the expiration date is mostly to get retailers to rotate their stocks properly than any other consideration. As long as the packaging isn't breached, I'd expect it to last indefinitely. One mixed, it will last about six months in a regular plastic Datatainer bottle -- possibly more with better storage.

The expiration date is required for a bunch of practical reasons, including to aid retailers in stock management. It is also required as part of ISO certification (when product that does have a limited lifespan is involved).

Most likely, the date reflects the fact that the packaging isn't impervious to damage - the handling it receives when shipped and when sitting on retailers' shelves, along with temperature and humidity variations, all together contributes to the developer inside having a limited lifespan. The date chosen reflects a very conservative projection of that limited life. Kodak (or Ilford, or ...) would rather be almost completely certain that your developer be good when you use it, than that you stock up on developer because of an expiration date that is far in the future.

To the OP: How long have you had the developer? How have you stored it? Have you any reason to believe that it has been exposed to harsh handling either since you obtained it or before?

Unless you have specific reason to doubt its efficacy, I would suggest you mix it up and, 24 hours later, develop a test roll. If that roll develops well, you can reasonably expect your developer to last as long as a package that is not so close to expiration.

One final point: I have seen innumerable posts here over the years where people have been tremendously concerned about maximizing the use of every drop possible of developer. While I don't like to waste money or valuable chemicals, I can't help but point out that developer itself is cheap - generally far cheaper than film or our time. If you end up wasting 25% of a package of D-76 because you don't use it up before the mixed developer starts to lose activity, than that is unfortunate, but it represents a tiny amount of money, and is more a sign that you ought to be shooting more film than anything else.

If your photography requires you to use large quantities of developers, there are choices available to you to minimize costs. If your photography only requires you to infrequently use small quantities of developers, there are choices (HC-110?) available to you make that more convenient as well, if you so choose.

Expiration dates are just a way for a manufacturer to cover their rear end and to help move products. This goes for all industries because the dates have so much padding to protect themselves. Very few thing actually go bad anywhere near those dates.

Here's a picture of oxidized (old) Dektol. I don't have any old D-76 on hand, but I would expect it to have a very similar color. This amber/brown color would also appear in mixed developer. This came from an old paper/foil bag.

A year ago I bought 14 packs of D-76 that were long expired (unmarked, thought to be from the 80's or 90's), in the old paper/foil packs. So far I've used one pack, mixed back in Apr/May, and I'm still using it. I have not had any issues. As long as the stock solution comes out a light wheat color, you're good to go.

I wouldn't be in a rush to use it. Stick it on a shelf, and when you have the need for D-76, mix and use it then.

Kirks518 said:

A year ago I bought 14 packs of D-76 that were long expired (unmarked, thought to be from the 80's or 90's), in the old paper/foil packs. So far I've used one pack, mixed back in Apr/May, and I'm still using it. I have not had any issues. As long as the stock solution comes out a light wheat color, you're good to go.

I wouldn't be in a rush to use it. Stick it on a shelf, and when you have the need for D-76, mix and use it then.

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By the way to check the developer when you mix a batch, just develop one sheet of film rather than a large batch the first time you use it.

Sirius Glass said:

By the way to check the developer when you mix a batch, just develop one sheet of film rather than a large batch the first time you use it.

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Even better, develop a short bit of 35mm film.

Mixed D76 in a FULL well stoppered glass bottle is good for 6 months just as Kodak says. I have a studio test set up and exposed, developed, printed film from a test 8 oz bottle, weekly for 2 months . then once per month. It works as intended for 6 months and a slow degradation sets in.

The secret is decant fresh mix to small one time use bottles. Mine are 4 or 8 oz.

Kodak says a half full bottle is good for 6 weeks. My test show 1 week is a significant increase in activity, after which it degrades. The Whole process is not predictable so I only use fresh unopened bottles.

If you want to punish yourself, run the test carefully on your own.