So I've googled this and found out that it's possible but there's naysayers obviously. Most negative comments are that the most viable yeast is in the primary but I've heard of people harvesting sediment from bottles and it seems to work fine. Anyway, I harvested some WLP051 from one of my cornies and it's on the stir plate at the moment and seems to be going fine. My only niggling doubt is that the yeast was very dark in comparison so other liquid yeasts that I've used which I'm not sure what to make of. I'm planning to harvest some yeast from my Kolsch that did not turn out right, I know this could be dodgy but I'll give it a shot.
So has anyone else tried this?
So I went and harvested the yeast from the keg and put it on as a starter. It seemed to work fine but I haven't tested it yet. I'll let yiz know how it goes.
This could be very interesting for those yeasts I keep forgetting to save. Let us know how it goes.