You can test it with a piece of enlarging paper.
See: www.covingtoninnovations.com/xtol

  Do you mean a partially filled bottle or one that's had
the cap off for two months. Assuming you mean the former
Kodak's life numbers are very conservative. The only way to
really tell is to develop some film and see if the density
and contrast are as expected.
  A test with a fogged scrap of film will tell if the
developer works at all but not if its developing as
expected.

I've developped a couple of weeks ago some films with XTol prepared
the 30th March of 2002. This means more than 2 years and a half
lifespan.
I still keep some of this batch to see if it can reach the 3 years, I
won't be able to test much further than this, I have only a few left.

I posted pretty recently on this NG (thread on ID-11 replacements) how
I prepare and store it, nothing special by the way, just common sense:

--------------------------------------------------------------------
- demineralized water
- part A *must* be fully diluted before adding part B, ambient
temperature water is used.
- stir without inserting air in the mixture
- brown glass bottles (pharmacy kind) fully filled (4x 1-liter + the
rest in 100ml)
- once the 100ml bottles are all empty, I fill them again with one
1-liter bottle
- 100ml is the minimum quantity for a 135-36 roll
- the 100ml bottles contain slightly more, as I use it 1+1, I just add
some more water to fill completely the bottle, then I complete up to
200ml for processing.
- bottles stored in the dark
--------------------------------------------------------------------

Regards,
Claudio Bonavolta
http://www.bonavolta.ch

In my limited experience with Xtol it's a bit "sneakier" than most
developers when it goes bad.  It doesn't change color or get an off odor,
makes it tricky.  If I were still running a big sink line I'd just monitor
developer activity with BW control strips, but not feasible with the volume
I am now running so I just use a different developer and one-shot it.

Phil,

This may not be a true test, but shouldn't it give some clue to use the suspect Xtol to develop
a test strip printed on photo paper without an incorporated developer???

Also, a few years ago someone on this group suggested using the mylar bladder in a boxed wine to
store developer.  I mix a 5 liter pack of Xtol in only 3 liters of water and store this
"concentrate" in a 3 liter wine bag.  Not long ago I found that the mylar bags can be obtained
from vendors of wine making supplies.

Bob
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