Yeast in airlock

[petree3]

I had a question pop into my head while staring at an experimental 1 gallon batch I have puffing away in a kitchen cupboard at the moment. This particular batch is some left over Irish Red that has Safale US-05 fermenting at ambient kitchen temp ~70. Being a rather warm happy fermentation I've had to clean out the three-piece airlock several times.

Here's my question:
There seems to be a rather pure yeast sample in the airlock tonight. No trub, just yeast cake. I know that commercial breweries use food grade acids to wash yeast and clean them of bacteria. So I wonder if the Star San in the airlock has not done any real damage to the yeast and perhaps it could be pitched into a starter and used on the next batch? This batch is purely experimental but the next one might not be. Thoughts?

 

[billl]

Eh - you might get luck and have it work. I don't think that's a reliable way to harvest yeast though. If you really want to top crop, just take a scoop with a sterilized spoon and toss it in sterile starter. Commercial acid washing is a much more controlled process optimized to not hurt yeast. Starsan isn't that same thing.

 

[dangerbrew]

Eh - you might get luck and have it work. I don't think that's a reliable way to harvest yeast though. If you really want to top crop, just take a scoop with a sterilized spoon and toss it in sterile starter. Commercial acid washing is a much more controlled process optimized to not hurt yeast. Starsan isn't that same thing.

I would not advise getting yeast that's been sitting around in the airlock, much less yeast that's been sitting in a Star-San filled airlock. Top cropping would DEFINITELY be much better, but even better than that would be just waiting for your bottling/racking day and harvesting the yeast at that time from the bottom of the vessel using the sanitized jars of boiled water technique. There's a sticky thread at the top of this forum about it called Yeast Washing Illustrated. Check it out.

 

[petree3]

I know how to wash yeast. Also, it's a one gallon container so I wouldn't be able to top crop. It was just a question of the viability of the yeast.

 

[dangerbrew]

I know how to wash yeast. Also, it's a one gallon container so I wouldn't be able to top crop. It was just a question of the viability of the yeast.

Well, only one way to find out for sure, eh?