Yeast starter calculator

[DaveEsposito]

If this has already been answered I apologize.

I've been investigating the yeast starter calculator. Everything makes sense except one thing.

Based on starting yeast count and other parameters it estimates total number of cells produced by using a starter (total available for pitching to the wort). My assumption however is that the number of cells it estimates is dependant on the length of time from pitching to the starter until I pitch to the wort. Is it assuming some standard length of time or am I not understanding this correctly.

Thanks.

 

[Josh (Brewer's Friend)]

Good question. As I understand it (and I'm not an expert on yeast growth), the attenuation and fermentability of the starter aren't taken into account in the primarily used growth equations. For instance:
http://braukaiser.com/blog/blog/2012/11 ... st-growth/

In this method, the attenuation is assumed to be 75%. So the length of time is really tough to say. From my experience, I haven't really seen people testing the FG of their starter, but mostly just wait enough time to be fairly confident that it's fully fermented. But in theory you could measure gravity and know it's finished when the yeast has attenuated to 75%.

I know this isn't the best answer, but it's how I think of it. Maybe someone else can add their opinion too

 

[DaveEsposito]

Good answer. I get it. Thanks for the reply.