Selecting for alcohol tolerance and high attenuation

[Bustapheara]

Hello, everyone. I'm a new member, and this here be my first thread.

Back in March, I went about culturing wild yeast from the North Park neighborhood of San Diego. After getting a jar of wort well inoculated, I brewed a small nursery batch, and have now brewed two full sized batches. The yeast exhibits an estery and phenolic character that makes it suited to Belgian styles. The only problem is that, at least in all malt brews of moderate gravity, it hasn't fermented below 1.020.

I would like to start pushing the yeast to become a greater attenuator, and to be fairly alcohol tolerant. I assume that one accomplishes this goal by pitching many successive generations into relatively high gravity worts, and letting the yeast adapt to that environment over time. Of course, I have zero experience with applying selective pressure in hopes of influencing my yeast's evolution, and my assumption might be total bull. Any pointers would be greatly appreciated.

 

[matt99004]

I am just starting down the same path. Today I plated a loopful of culture I had captured here near Cheney, WA. I plan on selecting a few colonies and seeing what sort of results I get on each one. As far as applying selective pressure, it all depends on the underlying genetics of the yeast captured. You can apply any pressure you want, but if the genes for tolerance and attenuation aren't present, then nothing will come of it. I suspect I will have far more failures than successes.