How long can I store my starter yeast?

[curtw]

Using instructions I found on HBT (but can't find right at the moment), I did the following:
- Made a 1L starter from a vial of WPL002 (English Ale Yeast)
- Decanted and saved off half of it into two sanitized mason jars
- Used the rest in a 3gal brew

So now I've got 2 mason jars with nice yeast in it. I could probably calculate the # of cells using yeastcalc if I wanted to, but...

How long can I store these in the fridge before the # of cells is so low that I'll need to step it more than once or twice? I see a wide range of cell count estimates for such "old" yeast that I don't know where to start.

Thanks!

 

[grathan]

I would say 6 months, maybe 9 months if you use this technique of storing in water:
https://www.homebrewtalk.com/entries/yeast-harvesting-novel-approach.html