Exponential purification?

Yeast & Fermentation
1

If yeast grows exponentially, then surely it should be possible to virtually eliminate undesirable yeast strains from a yeast supply simply by propagating it a number of times.

Eg. If I have a yeast supply that contains 90% of the yeast I want and 10% yeast I don’t, when I add this slurry to a starter, both yeasts grow exponentially to the point where the dominant yeast dominates at a higher percentage. If I were to take some of that new slurry and put it in a further starter, I should be able to get to a point where the yeast I want should be 99.9% dominant.

Has anyone got any experience or research to back this up?

2

How would you know for sure that both are growing at the same rate? Some yeast strains are more competitive than others.

3

That’s a very good point. Now that I’ve worked it thorough I realise the whole premise was flawed. Even at 10:1 ratio if they both grow exponentially at the same rate, they will still maintain that 10:1 ratio.

Good job I’m not interviewing for any software jobs this week. Duh.