Just a small update. I just got done freezing my yeast for the year and decided to do a little qualitative testing while I was at it. I used three different strenght glycerine solutions this time. 35% 50% and 60%. My plan is to see if different levels of glycerine affect the lag time when making the first step of starter from frozen yeast. If more glycerine = shorter lag time then I will assume that more glycerine = more viable yeast surviving the freeze. If I observe no appreciable difference, then I will stay with my current assumption that the yeast are just sluggish after freezing and need more time to regain activity. If Brewitt does some viability assays for us and contributes that information, then we should have a pretty good idea of what to expect from freezing yeast at home.