Giant "starter" - worth washing the yeast?

As an attempt to get more bang for my buck, i collected an extra 3gal runnings from a dopplebock a few weeks back. I just transferred to a keg to carb, and long story short, I'm thinking I might have ended up with a giant "starter", as this isn't a very tasty experiement at this point.

My question is, though, based on the following information, is it worth going through the trouble in washing the yeast cake (WY2206 - Bavarian Lager) to store up some viable & healthy mason jar samples? The batch went from 1.022 down to 1.009 at 55F in one month. Is such a low, atypical SG not condusive to healthy yeast growth for future use?

Thanks in advance.

The low OG of the batch won't hurt the yeast.

I wash and store some yeast anytime I can. It will keep very well in the fridge but freezing it in 15% glycerol works the best. I have about ten strains in the freeze and am always looking for a new one. Microbiologists have wierd hobbies, I am a yeast collector.

Cool, but i'm worried about the low gravity of the batch i will be collecting from. From what i understand, the lower gravity is condusive to growth vs. feeding, so i would assume it might actually be better (with relation to less stress on the yeast).