My experience mirrors Thomas's. No matter how old or funky the Xtol looks, ya have to try it. This last time I did some in Xtol I shook up the sediments, then filtered it thru heavy Chemex filter. Did a 250ml straight fresh Xtol top up replenishment, ran a test and bingo, same time and temp same awesome fine grain, great contrast and tones. I think my current batch is at least 3 years old at this point, 2 or 3. I think it gets better with age.