Pulled out a mason jar of wy2001 urquell slurry from March to make a starter the other night and when I opened the jar lid there was yeast up around the lid and even under the top. There was about 500ml of slurry in the jar with another 300ml or so of beer on top of it. So I'm not sure what went on in there at 36f in my serving fridge but it had a rather unsettling odor. I had already made the 2L starter so I pitched it. Foamed up like crazy when I shook it...got to thinking about it later on in the evening and sniffed it...nope...tossed it out.
Luckily I have another jar of it from Feb that looks ok.