Isolating strains

So my friend is going to do a turbo yeast pack. I wanted to isolate the strain off of his yeast cake and amplify it for use. Is turbo yeast generally single strain or can I isolate with like 15-18% ethanol on a maltose plate? I wanted to plate out, select single colonies and select a viable culture on a maltose+ethanol plate and then move to amplification.

Btb, its been about 15 years since microbiology in college so I might be a bit rusty.

That will probably work, yes. I doubt anyone here actually knows that turbo yeast represents a single strain, but it would be pretty surprising if it didn't.

Why you would want to do this, though (unless just for the hell of it) is completely beyond me. Turbo yeast isn't expensive, and if his yeast cake is from a high alcohol fermentation then it is already as pure as what you'd get from this. Your method for selecting for the turbo yeast is to plate it on high alcohol agar, presumably assuming most other things will die. You're probably right, but you're taking it from a high alcohol liquid! You're not actually going to be accomplishing any selecting here, or from the opposite angle, the selecting has already taken place within the wort.

Well, often times, I am a dummy, plain and simple, and I miss things like that, LOL. Thank you, I totally overlooked that I was sampling from a high alcohol solution already. I am interested just so I don't have to order it online--I am impatient. Mostly I want to have the strain as a novelty--shhh, home brewing is an excuse to practice microbiology--but we are going to practice isolating and purifying so we can breed our own yeast. I was worried that the yeast would go dormant in high alcohol conditions, but if it kills them then I have nothing to worry about. I guess I should give it a try.

If you're preserving it for regular use, I'd put it in a glycerine solution and throw it in the coldest freezer you can manage. Agar plates look impressive, but they're a pain in the ass for long-term storage (and aren't used that way in microbiology when there's any alternative). The agar dries and cracks after a month or two, the parafilm around it inevitably breaks, and it's just a nightmare.

I will definitely try that. Does glycerine force the yeast to go dormant? we kinda glossed over s. cerevisia in Micro in college. Well, hopefully I'll learn all about S. Cerevisia now.

No, the freezer forces the yeast to go dormant. The glyercine stops you from killing it in the process.

Ahhh! See what 14 years of nothing but computers--well I did do some pharm validation but not micro--will do to what you learned in college, lol!