[uisgue]

 After every batch that I brew, I dump the yeast and trub onto the ground behind my house.  It is mostly redwood and other conifer needles over dirt and moss.  Is it possible for that yeast to survive and maybe even interbreed with other strains of dumped yeast?  In particular, might that be a possible spot for spontaneous fermentation?

[dimik]

Oh I'm sure there is plenty alive yeast there. I'm not sure what it is exactly that you're asking though...

[morticaixavier]

If you mean capturing 'wild' yeast then if you do it there you will likely get a mix of all the yeast you have dumped in the area + various airbourne batcteria and other yeast. If yo have an orchard or vineyard near you, or know your area to produce good sourdough bread that's a better bet for getting novel yeast I would think.

[erockrph]

I say go for it. Maybe try to get a wild starter going and see how it pans out. Rig up a makeshift coolship and see what grows.

[tschmidlin]

Some of the brewing yeast will likely survive, but it is unlikely to interbreed with wild strains.  In order for their to be mating, their needs to be sporulation, and every brewing strain I've tested has been severly sporulation deficient.

[dimik]

I've seen yeast form ascospores, and they were taken from the bottom of my fermentor.

[tschmidlin]

The few tetrads I was able to find after growing on sporulation media I dissected and checked for viability.  None had 4 viable spores, most had only 1 that formed a colony, but some formed 2 or occasionally 3.  In general, the colony morphology was very nibbled, indicating genomic instability.

You might have better luck than I did though.

[kylekohlmorgen]

Try before you buy on this one...

Definitely make starters and leave them in areas where you want to try spontaneous fermentation. There are a few accounts recently of homebrewers doing this successfully, but I have tried capturing wild yeast in my area and have been WILDLY unsuccessful.

Still doesn't deter me from making "wild" beer... I just use the "wild" yeast and bacteria from other regions