Quote Originally Posted by Photo Engineer View Post

I thought you had added more Metol to the concentrate to estimate how much was oxidized. If so, which concentrate did you use? Was it the original or the "enriched" and younger version?

No, I added some ascorbic acid to this batch. I have several batches going now, but this is the oldest. The problem is that it's going to take a year to determine keeping qualities if it's any good. Much less, of course, if it's not. I'm hoping that a time history of some number of tests from the same batch will show a trend before a year.

It was another poster who added Metol to his 1/3 bottle of old Metolal. I'm still learning. It seems I can get very good results at pH=11 or less in the working solution, but I don't trust either my pH meter or my ability to use it. It does read close to 14 in a stiff solution of KOH.