Tired of slow starts, I made my first starter and planned to pitch at high krausen (which happened at 24 hours on the stir plate.) Couldn't brew, so it went in the fridge and after a few days, I warmed it to ambient over 12 hours and planned to brew. Couldn't brew (again! 
) so now I plan to leave it at ambient, RDWHAHB, and use it when I can brew in another 2 days.
But, being a tech geek, it DOES leave me VERY curious about a few things:
1. When is the optimal time to refrigerate a starter after high krausen? I've read that you want to let the yeast to go through their life cycle in order to build up their glycogen stores. So, does that mean taking it off the stir plate and letting it flocculate out before chilling? What affect on viability does prematurely (in this context) crashing the temp have?
2. What is the rate of death for yeast at 70F (room temperature) v. 35F (refrigerated?) Of course, it is slower when refrigerated, but how much more so? I've seen the 25% per month number, but assume that is when refrigerated? Where does that number come from? Anyone have a reference (other than White Labs FAQ) page to point me to?
3. What affect on yeast viability does temperature cycling have? I.e., if I warm it up anticipating to brew but can't, then refrigerate it again, what happens?
Brian
) so now I plan to leave it at ambient, RDWHAHB, and use it when I can brew in another 2 days.But, being a tech geek, it DOES leave me VERY curious about a few things:
1. When is the optimal time to refrigerate a starter after high krausen? I've read that you want to let the yeast to go through their life cycle in order to build up their glycogen stores. So, does that mean taking it off the stir plate and letting it flocculate out before chilling? What affect on viability does prematurely (in this context) crashing the temp have?
2. What is the rate of death for yeast at 70F (room temperature) v. 35F (refrigerated?) Of course, it is slower when refrigerated, but how much more so? I've seen the 25% per month number, but assume that is when refrigerated? Where does that number come from? Anyone have a reference (other than White Labs FAQ) page to point me to?
3. What affect on yeast viability does temperature cycling have? I.e., if I warm it up anticipating to brew but can't, then refrigerate it again, what happens?
Brian
