Washing "old" yeast

[Frodv]

Hi, I was wondering if it is possible to wash a yeast that has been sitting in my fermenter under pressure for several months? It is only the yeast and trub that has been left in the fermenter after transfer, I have not bothered washing it yet and the temperature has been all over, but as I mentioned, it had been kept under pressure ( 1 bar) since it started fermenting...
Thoughts? Wash or dump?
The yeasts are US-05 and W34/70 (two different fermenters).

 

[bleme]

I wouldn't trust it without making a starter, and if I'm going to bother with a starter, I would make the starter now and harvest that yeast.

Now, if you had asked "would you?" or even "should I?" instead of "can I?", I'd have a very different answer.

 

[Bubbles2]

Prob gonna have off taste... I harvested 3 times / washed, etc. Not worth the 'rub'. I use SAF05 2.99 a pack.
Now if you have your recipe perfected and now want to try using a different yeast for a different style. I'd be more apt to take that type of new yeast, decant some clean yeast off the packet, and build it like you would a sour dough starter feeding it a neutral DME and pull off that. Of course you will have to 'start' that packet you stole from to get enough cells to go (if it is a strong beer).
Personally I think people coddle their yeast a bit much here, we bake a lot and with that we understand our little friends.

 

[VirginiaHops1]

I harvest yeast into mason jars and will reuse without a starter within a few months. Awhile back I had one lone mason jar of Wyeast 1318 left, looking...not well. Far more brown than white. I decided to make a starter with it to see what would happen. It was a pretty ugly starter and seemed to have a lot of trub/dead stuff in it, but that tends to sink faster than healthy yeast. So when the starter was done I was able to swirl the flask, and after 5-10 minutes transferred to a couple new mason jars and left the stuff on the bottom behind. When those mason jars settled I had what looked like healthy white yeast on the bottom.

That said I haven't brewed with this stuff yet, so I can't attest to it's performance vs fresh 1318 from the manufacturer.