« Last post by toby on September 03, 2015, 05:17:05 PM »
I strongly empathize considering my own recent issue with a couple of stored yeast samples. The main difference is that I'm uber paranoid about it at the moment, since this was a relatively rare case for me. I had isolated and stepped up some WLP028 and WY1728 collections since I've been brewing more Scots ales this year. Well, when I brewed my BrewUnited Scotch Ale, I figured I'd make a 1L starter out of two of my small jars (since it's a really big beer). I was nonplussed when the first jar I pulled had this thick crud at the top. Apparently I had picked up a contamination in two jars since pulling another two turned up one with a slight film (I'd describe it as a starter pellicle). I took a closer look at all the other jars, and only those two seemed to have issues, so they're going to get a special treatment. But, my philosophy is to trust your senses and not assume. I visually and olfactorily (not even sure if that's a word, but I'm going with it) checked all the rest before settling on the 2 I used. Only the WLP ones had the issue curiously. These were only 2nd generation, though, so I'm assuming more an isolated issue with those 2 jars (out of 10 or so).