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Keeping old yeast fresh

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beerisyummy

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Howdy Zymurgists!

I have 3 or 4 yeast strains that I like to use repeatedly. I don't want to bother with washing yeast, so I typically make an extra liter of starter and toss it in the fridge in an airtight container. When ready to brew another batch, I then decant and pitch into freshly made starter wort. I've always gotten away with it until this last time, when I tried to rev up some yeast that was a little over 6 months old. (I brew once a month, so every one of the 3 or 4 yeast strains does not get regular use.) It did not wake up, so I had to go and spend $8 (oh the horror) on a fresh vial.

A fellow at my LHBS suggested I could avoid killing off the yeast in storage by periodically adding fresh wort.

So I'm imagining making some extra extra starter wort, opening the oldest refrigerated yeast, decanting some or most of the liter and adding the fresh extra extra wort.

Anybody do this? Should I worry about jar bombs in my fridge?

Thoughts?
 
Everybody has their process. I did the Mason jar thing but was taking up too much space in the fridge.
I now make a 2L starter and when complete I harvest 2 50ml vials right when I take the flask off the stir plate.
I use those vials for the next starter. I'm currently on the 4th gen of harvesting from the initial pack of yeast.
 
I guess I've never had a problem with a mason jar of really old yeast - in fact, I just brewed yesterday with some really old yeast. Must have been 7+ months old, but had to do a step starter.
 
With older, stored yeast it may take a few days to a week on a stir plate to get enough growth. I always keep the starter spinning until it turns color from dark or medium brown to a light tan creamy milkshake. I give it another 12-24 hours after that color change.

BrewUnited's Yeast Calculator
 
With older, stored yeast it may take a few days to a week on a stir plate to get enough growth. I always keep the starter spinning until it turns color from dark or medium brown to a light tan creamy milkshake. I give it another 12-24 hours after that color change.

BrewUnited's Yeast Calculator
Perhaps I didn't wait long enough.
 
I've been looking all over for yeast under saline. Can't find it. Apparently didn't bookmark it, and can't get the right Google search. I'll post a link when I find it
 
fwiw, I'm guessing "saline" was supposed to be "glycerine" as the latter is a common practice and the former I've never heard of...anywhere...

Cheers!
 
A fellow at my LHBS suggested I could avoid killing off the yeast in storage by periodically adding fresh wort.
That's usually done for sour cultures.
But yeast in the fridge is (mostly) dormant. From what I gather it may be best to keep her that way, stored under beer, not adding wort.
I've had a few bulging lids from harvested yeast, in the fridge.

Some stored Belgian yeast slurries started to kick up as soon as I took them out of the fridge. First bubbles and small bits traveling upward, resulting in the whole cake floating up and pouring out from under the loosened lid.
 

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