[James Lorden]

If yeast is harvested but not used for a while I wonder if that yeast can be made into a starter, fully fermented, and then saved again.  In other words will adding the saved slurry to a quart or so of wort revitalize the yeast and keep them viable.

or,

Is the opposite true, would adding the slurry to a small volume of wort actually deplete the glycogen of the good yeast in the sample and not provide enough nutrients to replenish the reserves?

Any thoughts?

[weithman5]

i periodically will make a starter and save it from old slurry.  i think of it as not much different except order of magnitude, from harvesting yeast from a commercial bottle conditioned beer.

[davidgzach]

I'm sure it can be saved, but you still have the old trub in there.  Maybe make the starter, but transfer to a 1G fermenter at high Krausen to get just the fresh and healthy yeasties?  Just a thought.

Dave

[tschmidlin]

If yeast is harvested but not used for a while I wonder if that yeast can be made into a starter, fully fermented, and then saved again.  In other words will adding the saved slurry to a quart or so of wort revitalize the yeast and keep them viable.

Yes, this is exactly what you should do to keep the yeast longer than normal.  It may deplete the glycogen reserves of the existing yeast, but what good are glycogen reserves if they die?  Make a good starter and it will grow new healthy yeast cells.