I have been rinsing yeast and storing in 30ml vials for several months. Now I am getting a similar sulfur smell from all of them. All are 2-4 months old. WLP001, upon opening after 4 months, foamed over heavily and gave off a strong sulfur odor. I dumped them all, thinking they were contaminated.
I recently opened a similarly stored vial of wlp530 and found a very similar odor with a bit of foaming. I made a 1L starter out of it and found that the starter smelled fine after it really got going on the stir plate. I pitched a vial in a small test batch and it smells/tastes great.
Out of curiosity, I opend a small mason jar of 001 tonight which is 5 months old. It vented a bit of pressure and had the same smell, just not as strong. All were rinsed with boiled water and containers were thoroughly boiled as well. Any thoughts on what is going on?