Year old yeast

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk:

JuanMoore

Getting the banned back together
HBT Supporter
Joined
Oct 19, 2009
Messages
29,305
Reaction score
7,111
Location
The Old Pueblo
I have a few vials of white labs yeast that are 10-11 months old. I plan on making a starter to see if they're still viable, and then stepping them up if so. My question is what size starter should I use for the first step? There seems to be a lot of conflicting and unsure information about long term yeast viability, and I want to make sure the inoculation rate isn't too low for the first step. Or does it even matter for the first step?
 

el_caro

Well-Known Member
Joined
Feb 3, 2011
Messages
606
Reaction score
34
Yes there are many schools of thought on this one but I suspect whatever path you take will get a result.
If you believe YeastCalc then you have only around 1% viability while Mr Malty suggests 10% viability.
Some who have conducted their own tests suggest these figures are too conservative and the figure would be significantly higher.

If I was aiming for around 200Bn viable cells.

If there is in fact only 1 Bn viable cells as YeastCalc suggests then I would probably do it in 3 steps
0.5L , 1L then 2L

If I believed Mr Malty's suggestion of 10Bn cells then I would probably still start with 0.5L then a 2L.


It would be great if you tried different options of starter size and SG of wort and report back the results. I for one would be most interested.
 

DurtyChemist

Well-Known Member
Joined
Mar 22, 2012
Messages
1,555
Reaction score
153
Location
Reno
Calculate the efficiency of the yeast. That will help you determine it's viability.


I personally would go straight to 2 L starters and castle based off a 1050 brew.
 
OP
JuanMoore

JuanMoore

Getting the banned back together
HBT Supporter
Joined
Oct 19, 2009
Messages
29,305
Reaction score
7,111
Location
The Old Pueblo
Thanks guys. I used a 1L starter for the first step on the first vial, and it started to take off at the 30hr mark. That kind of lagtime tells me I should have started smaller. I think I'll start with 500mL for the others, and then step up from there.
 
Top