Yeast viabilty issue

[wes200x]

I have a vial of white labs WLP300 with a best before date of 12/12/2011. Beersmith 2 says the viabilty is of 36.5% when i set the production date at 8/12/2011. I made sure and set the brew date was set for today because i know that were it gets its date to calculate the viability. Mr Malty on the otherhand says it is 12% with the same 8/12/2011 entered. any reason to the huge difference thanks

 

[Kaz]

Beersmith has an options page for the yeast starter calculator. In it there are settings for viability and aging rate. My guess would be that the aging rate that Beersmith uses is off from what Mr. Malty uses.

 

[helibrewer]

In any case, just do a step-up starter and you will be fine

 

[wes200x]

So i am now wondering what do your great minds think is closer 36% or 13% any comments or what do you think my step up volumes should be with the starter. I am using a shaker table with pure oxygen with .5 micron diffusion stone.