I'm feeling conflicted about my yeast starter approach for tomorrow night, so I'd like to crowd-source an answer and see what comments I get. Basically I'm brewing a 5.5G batch of Marzen tomorrow night with WLP833 and need to get some yeast ready.
My plan is to do a SnS starter and pitch the whole thing at high krausen. Since I'm brewing a lager, I'm planning to do the starter tonight or first thing tomorrow and leave it in the ferm chamber at ~50F for 12-24 hours. That way I don't temp shock the yeast when I pitch them into 48F wort late tomorrow night.
I have two choices for yeast:
1) 500mL of WLP833 slurry from a Dortmunder (brewed 4/17, harvested 5/4, ~30 days old)
2) 3 vials of WLP833 that I already received from my LHBS (cheap since they expired on May 20)
The slurry performed well and has been stored ~38F. However, my GFCI tripped earlier this week so the chest freezer that the yeast was in warmed to ~68F over a period of ~12 hours. Once I discovered the issue I slowly decreased the temp back to ~38 over ~12 hours (to prevent shocking the yeast and/or breaking any glass bottles in contact with the walls of the freezer).
The vials were stored at the LHBS the whole time so I expect they've maintained proper temps.
Seems like either would work fine, but why make a decision and second-guess myself when there's such a great resource at my fingertips