Interesting Lager Yeast Activity - Question on Viability

[cactusgarrett]

I'm planning a helles shortly, and started up a pack of WLP-833. However, for sh!ts & giggles i also took an old pack of OYL-114 (Bayern) and did a 1L starter with that - really as hail mary to see if anything was still alive. I've wanted to use this strain for a helles but never got around to it, so i figured a starter to see if it would do anything wouldn't set me back.

The OYL-114 pack was manufactured in Feb (7 months old) and every pitch rate calculator says there's 0% viability, but the 1L starter (stirplate) I made two days ago clearly shows signs of a typical lager starter activity. I plan to step up this starter again to 2L once this current starter fermentation dies down.

Despite the theoretical 0% viability, do you think this final 2L starter would be viable to ferment a 1.055 helles after these two step-ups? Or should I play it safe and use the WLP-833?

 

[bierhaus15]

Those viability calculators are always way off in my experience; at least when comparing them to actual tested slurry viability. That said, I've seen 30-50% viability on some yeast packs well over a year old. Yeast are pretty hardy creatures.

Still, I would not expect a stepped up, 2L starter made from old yeast to have nearly enough yeast for a proper lager pitch. Likely would be looking at 4L or so.

 

[cactusgarrett]

Still, I would not expect a stepped up, 2L starter made from old yeast to have nearly enough yeast for a proper lager pitch. Likely would be looking at 4L or so.

Ugh, I don't like the idea of putting a full gallon starter into a 5 gallon batch, so maybe i'll get that going now so there's enough time (brewing in 4 days) for it to ferment and flocc out to allow for decanting.

 

[Conehead]

I just made a Marzen using 5 month old OYL-114 and BF said it had 0% viability. I emailed Omega yeast and they said a 1L and 3L would be fine. And it was. In fact, I had a very active fermentation ( 52F ). Great yeast and I am going to re-use it.

 

[cactusgarrett]

I just made a Marzen using 5 month old OYL-114 and BF said it had 0% viability. I emailed Omega yeast and they said a 1L and 3L would be fine. And it was. In fact, I had a very active fermentation ( 52F ). Great yeast and I am going to re-use it.

Thanks; good to hear. Yeah, even using a calculator and simulating a 1L then 2L step up from initial 1% viability ended up with theoretically a high enough cell count. And there's clearly was some viability in my pouch.