Washed yeast autolysis

[dcan6303]

Hi brewers,

I have a German Bock lager yeast that I harvested and washed from the yeast cake of a Vienna lager brewed in March, so 3-4 months ago. I'm brewing an Oktoberfest soon, so I pulled this out of the fridge last night to spin up a starter and see if it was any good. It had a bit of a meaty / vegemite smell so I suspect there is some yeast autolysis. The water tasted like weak bonox, but not infected. I pitched it into the starter anyway, and it looks like there is activity this morning. I'll let it go another couple of days and taste that to see how it goes.

My question is this: Assuming I get healthy starter activity, will the active yeast consume the dead yeast and compounds that are giving the autolysis smell and taste, or is it always destined to struggle. Is an active, attenuated starter considered healthy regardless of the age of it's source? Or is it all a bit dodgy considering its going in a lager and I should just grab a new vial.

Cheers, Dave

 

[Yob]

Mutation is the worry,

You can always rinse the dead yeast out but you can't wash mutation. It's a sign the yeast were struggling to survive in the fridge and turned to the available food source..

It's why I freeze now.

 

[dcan6303]

So stress do to environmental conditions is a cause of mutation? Interesting. I knew mutations were more likely to occur with each generation.
This is the second time I have washed this yeast, so maybe that combined with a few months of storage could be a problem.

 

[Yob]

Where there is oxygen and a food source, yeast will try to adapt to the environment, fridge temps slow their metabolism but it's not in hibernation. There will be a slow drift as cells die and the others strive to live.