Hey there, i want to brew a pilsner and my buddy gave me a baby jar of yeast that he properly froze with glycern. He washed the yeast from the bottom of the primary of wyyeast czech pilsner, and its bin frozen for like 6 weeks maybe. I usually use the mr malty calculator for pitching, and a excel calculater from "yeast" for stepping up my yeast. What should my viability percentage be? Is is gonna be the same and storing slurry in the fridge? id like to step it up and double it so i can store it, but id like a rough cell count so i can pretend i know { lol } how much yeast is in the jar. Any ideas?
frozen yeast viability
- Thread starter ukeedogs
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
No way to really know. There's some rules of thumb on how many cells in slurry, but it's a big guess.
To really know, you'd need a microscope with at least 400x optics, a hemocytometer, and a stain (methylene blue or citrine violet) to determine viability. Not many brewers have that, so...
Just grow a starter from what you have, decant, step it up with wort, repeat until you think you have a lot of cells. I've got a starter of Wyeast czech pilsner yeast that I've stepped up in a 4L flask several times, preparing for a 10g batch of beer.
ive always went by mr maltys calculator set on slurry and had no problems with under/over pitching, so what im really asking is, should i expect the same viability from the 6 weeks frozen slurry as a 6 weeks in the fridge slurry? thanks for the reply!
dbals
Well-Known Member
Sorry, meant citrate methylene violet. I've got some, I've used it, I haven't had time to do a qualitative analysis of it's merits vs. methylene blue, but the comparison is already available elsewhere.
I got mine directly from White Labs.
The violet is much more accurate with low viability measurements, but again I can't quote numbers myself. I really wish I could, and I have the equipment and materials to do so, I just haven't taken the time. Sorry.
dbals
Well-Known Member
Thanks for the info. I should of searched Sigma and would of found it without bugging you- sorry about that.
I just started digging around some on staining recently and finding papers, as I've been following the blogs of a few yeast wranglers. Good to see interest in finding other stains instead of the just old standby.
Thanks again,
Dan
I just started digging around some on staining recently and finding papers, as I've been following the blogs of a few yeast wranglers. Good to see interest in finding other stains instead of the just old standby.
Thanks again,
Dan
