Single Step VS Multi Step Starter efficiency

[GeorgeWilliam88]

I am using the pitch rate calculator to determine how big of a starter I need. While playing around with the numbers, I noticed that doing two steps with 1L per step yielded more yeast than a single step with 2L. Why is this? Its the same amount of DME...I would think that should yield the same amount of yeast but apparently this isn't the case. Anyone able to "explain like I'm five years old" why that is?

 

[Mark Farrall]

Placeholder until someone with actual knowledge chimes in...

I'm guessing because you get two growth phases. The second growth phase in the one litre starter will have a larger starting count than the starting count on the two litre starter. So even though it'll probably be a shorter growth phase, it'll start with a higher number and end with a higher number.

The growth phase being the part where the yeast bud until they work out there's enough of them and the fermenting starts in earnest.

 

[GFHomebrew]

This should help
http://braukaiser.com/blog/blog/2012/10/08/yeast-growth-experiments-some-early-results/