We did, in fact, write something here
years ago about the shelf life of developer concentrates. I’d now like to say a few words specifically about the FX-39.
It’s based on Willi Beutler’s Neofin Rot, and Willi Beutler and Geoffrey Crawley were friends.
The formula is somewhat daring, as the sulphite content has been reduced so significantly that, using modern developer substances and a superadditive system, we end up with a developer that both increases sensitivity and provides sharp results. One minor drawback is what we might call its ‘cosmetic’ shelf life.
Tetenal bottled Neofin in glass vials. That’s hardly feasible these days – in other words, nobody’s going to pay us for that ;-)
ADOX has already done everything possible here to modernise and stabilise the product.
We wouldn’t be ADOX-FOTOIMPEX if we didn’t also have the confidence to bottle the whole thing in our oxygen-barrier 100ml bottles under an inert gas atmosphere and sell it to you as an easy-to-prepare concentrate. It works, mind you, though the bottles usually don’t look so good after one or two years’ storage. Lina and I develop all our films in FX-39 II, and recently we’ve been over the moon, as FOTOIMPEX has sorted out a lot of bottles and given them to us for free.
The purpose of this short post is to discourage you from disposing of FX-39 II (and thus creating unnecessary waste) if the bottles look like the one in this picture:
This brown discolouration clings to the sides of the bottle, but as long as the liquid inside hasn’t precipitated (crystal formation) and is as clear as it is in the measuring cylinder, FX-39 II will work reliably.
For the 100ml bottles, we do not recommend making partial batches; instead, you should prepare and use one litre from the 100ml bottle.
Caution should only be exercised if:
1) The concentrate shows
signs of precipitation 2) The small bottle has been opened previously or the aluminium seal is damaged
Otherwise: Happy developing!
PS As with all organic mixtures, FX-39 is best stored in the fridge (approx. 5°C – NOT in the freezer!). We once left a bottle in the lab fridge behind a sheet of paper. Production date 2019, used in 2026: still in perfect condition.
