# Stepped starter

I am planning on using a 3711 pack from 7/25/11 on a saison noir of about 1.080 OG. Mr. Malty wants me to use 3 packs in a 2.8 L starter to get 287 billion cells. I only have this one pack to work with and will likely need to do two steps.
At 22% a 4L starter will get me 88 billion cells.
Decant this into another 3L starter should get me enough, right?

Assuming you’re starting with 35 billion cells and using “intermittent shaking”, it looks like 1 L, then 2.5 L should be about right.

I use an orbital shaker. I am having trouble with the math involved with multiple steps. I tried the Wyeast calculator and this does not include the viability but does factor in multiple steps. Mr. Malty factors in the viability but does not give information on multiple steps.

Per Mr. Malty
A 22% viable pack with assumed 100 billion cells should give 22 billion cells.
A 2L starter should double this to 44 billion cells.
A 1L starter pitched to a 4L started would give me 88 billion cells.

A 2L starter pitched to 4L starter would give me 176 billion cells, still too small.
A 3L starter pitched to 4L starter would give me 264 billion cells, just about right.

Any thoughts?

I was estimating viability based on the date you gave, and a loss of 25%/month. 0.75^3.5 = 0.37, or 37 billion cells. If you’d rather start with 22 billion, that works too. The growth factor is enough that it doesn’t make a huge difference.

http://seanterrill.com/2010/03/08/two-s ... culations/

Using the “stir plate” setting:
1 L first stage yields ~100 billion cells total.
1.64 L second stage yields 287 billion.

Very much appreciated!