Concern: Overpitching With Harvested Yeast?

[alfista]

Hi All,

I just started harvesting yeast and was planning on using some in the near future. I harvested the yeast about 2 months ago and it looks healthy, but for the first time I'm using Mr. Malty to calculate starter sizes, etc. How does one determine the cell counts they are starting with, and their viability %? Or is this just a rounding error for a mid-level home brewer and I should just create a starter and if it smells good, pitch?

Thanks,

Jason
P.S. Did do some searches, and read most of microbiologist thread but I'm still confused.

 

[Homercidal]

Not sure how they come up with cell count advice other than experience. They are using lab equipment to count cell and cell viability. You won't have this luxury, so you'll have to estimate.

One of the downsides to harvesting is not actually knowing how many viable cells you have working for you.

I think it's safe to say that you will be starting with fewer cells unless you drank like 2 6-packs to get your harvested cells. From there you can step up the starters until you get close to the Mr. Malty recommendations.

However, take those recommendations with a grain of salt. For one, he cannot know for certainly how many yeast live or die in your particular vial/packet of yeast. There are environmental factors to consider.

My advice would be to make up the recommended amount and see what happens.