Another Re-using yeast question

[Mk010101]

Ok, I've spent some time going through the search feature and trying to find my specific answer, but so far haven't found it.

I have read on these forums that you can reuse yeast 3-5 times (even read up to 20 times?!?) Does this include starters? This is what I mean when I ask this question:

I bought some lager yeast strain and plan on brewing a number of lagers with it. I was planning on taking a smack pack and making a starter with it. I would then divide that starter into 2 portions, pitching 1 of them, and saving the other. Does making a starter mean that I have "used" the yeast once? Does this mean I can only "reuse" the yeast 1 more time from the cake of the 1st one that I pitched? I am trying to not only be economical, but also maximize the utilization of the yeast.

Second question isn't as important, but similar: one takes a new strain, makes a slant (for simplicity, he makes one slant.) Then he makes a starter wherein he takes yeast from this and makes another slant. Can this go on ad infinitum (obviously assuming perfect sanitation methods?)

 

[teresalgl]

Personally, I think you can reuse yeast as long as you want -- if you like the results.

 

[apratsunrthd]

1st question: This is absolutely fine. However, keep the age of the starter you're 'saving' in mind. Store cold and use within a week or two. I count starters more as a 'half-generation.' That said, 3-5 generations is not a hard and fast rule. Lager yeasts tend to become less flocculant with successive generations. My suggestion: use it until it's too cloudy/powdery.

2nd question: Absolutely. This is how I've built my yeast library.

 

[Calder]

I don't count the starter as a generation. It's conditions are not as harsh as a beer (lower density, lower osmotic pressure, less weight of liquid pressing on it, lower alcohol, usually shorter time period, etc), so there is less likelyhood for a mutation.

Use for as many generations as you like. Just be aware that the yeast will change over time (less or more flavors, lower or higher attenuation, lower or higher flocculation, etc). If you like the results, keep using it.