I'll answer what I can. I researched the crap out of yeast life cycle etc before doing this. Just answering from memory and it's been awhile so feel free to check my facts.
Yeast must prepare wort for fermentation by lowering the pH to acidic levels so you end up with a lag time based on starter batch size. Smaller volume=quicker start.
Pitching a starter at fermentation temps and holding it at those temps w/o using a stirplate is just like fermenting a small batch of beer and will result in no off flavors from oxidation. If you stir for a limited amt of time...and I don't remember the exact cutoff time...the yeast will use the O2 youve put into solution for fermentation and the starter will not oxidize. As stated above, I stir till I see small bubbles at the edge of the jar and stop but never stir over 5-6hrs. Not vigorous just enough to keep yeast suspended.
New info has come to light about total yeast count not being as important as yeast vitality. Makes sense. Build starters and crash--youre putting them to sleep. Active high krausen and they've got their pads on and are ready to enter the game.
As far as other concerns such as pitching your high krausen or fermented starter into oxygenated wort. I gently pour the starter into the wort after oxygenating it.
My WAG WRT this not being a problem with oxidation: Whatever amt of O2 you introduce into the fermented starter volume will be used for fermentation.
well I'm considering giving this method a go on my next lager.
the specs and initial conditions are as follows:
10 gallon batch of lager
OG of 1.051
vial of WL833 (best by some time in December)
I'll make a small starter on the stir plate ahead of time. Probably 1.5L. I'm not sure if I should crash it and decant first. I'll take suggestions on that.
I'll mash in at night. And I'll be mashing thin, like 2.8 qt/lb thin. My first runnings should have a gravity around 1.046.
So after an hour I'll collect 1.5 gallons of first runnings (this seems right based on yeastcalc) and boil it for 20-30 minutes. I might even toss in a few hop pellets b/c hey why not?? I'll then chill this and pitch the yeast in and let it ferment at appropriate lager temps (50Fish) for the night.
The following morning I'll drain the rest of the mash tun, do the world's smallest sparge on 10 gallons (1.5 gallon sparge) and finish making the rest of the wort. My hope is that by the time I have this wort chilled the first 1.5 gallons will be really chugging along and I'll be able to pitch it in that day.
Any problems or suggestions here?
Edited by Evil_Morty, 30 September 2015 - 05:15 AM.