Cultivating commercial yeast

[Hikeon3]

So recently I've had the good fortune to find two things at a few mom and pop liquor stores in my area.

1) A six pack of Dead Guy Ale that must be at least a year or two old. It barely tastes like the Dead Guy I've had in the past. But the great part about it is that the bottoms of the bottles are absolutely coated with yeast.

2) Three bottles of 2005 Double Bastard that have that same creamy yeast layer all over the bottom of the bottles.

Well my question is two-fold. First of all, being that these are old bottles, how viable is this yeast and will I be able to get some cultures going? Second of all, what are the key steps to accomplishing this feat?

I mean I figured you basically are creating a starter, but with the slurry from the last 1/3 inch or so off of the bottom of the bottle. Then if the culture gets moving slowly, pitch that slurry into another starter and keep culturing until you have an appreciable flocculation of active yeast. Am I right?

Any input is much appreciated. Thanks!

 

[devaspawn]

Can't speak to the viability of the yeast at this point but your process is sound.

 

[oguss0311]

That's quite literally how I have been harvesting yeast from Brewery Omegang's Wit every time I make a hef. And I've had more luck with this procedure than I have with store bought yeast! I've even stored the yeast after I culture it, reactivated, and brewed months after I was done with the original bottle of beer. See yeast washing on here to learn how to store it.
As for the yeast- I saw a show "how things work" where they highlighted beer. They mentioned that people have SUCCESSFULLY cultivated yeast from bottles found in old shipwrecks. Old shipwrecks! Plus- if it does not work out- you still get to drink the beer, and your investment of a few dollars worth of DME is no painful loss. And if it works- you have Pacman ale yeast! I'd Love to have that! (I got into brewing just After Wyeast sampled it as a strand that they sold.....)
Go for it and let us know how it goes!