How many generations of starters?

[sicktght311]

Backstory.....I brewed a NEIPA with Imperial A38 Juice back in Feb of which i built a yeast starter and split the starter into 2 jars. One for the NEIPA, one for the fridge for the future. I also did the same with Imperial Barbarian as i was going to brew a Heady Topper clone, but never got to brew it. Two jars in the fridge, likely around 200b cells each when i jar'ed them in late Feb/Early March. Fast forward a few days later, my father passed away, and then 2 days after driving to Florida for that, my house filled with smoke and soot due to a faulty oil burner. Entire basement and brewing area had to be torn apart, cleaned, etc. But everything in the fridge was unaffected since its a fridge that doesnt have a fan/vent system to distribute the air. Plus they were in sealed containers.

SO

I saved them, and have been planning to use them for the future, but by this point, they're likely degraded down to about 25% yeast viability at most, giving me 25-50b cells to work with. Originally i thought "JUST DO A BIG STARTER TWICE!", but now i'm reading i should be doing successive smaller starters to build back to a point where i can treat the yeast as if it just came in brand new packaging and i can build a starter for a brew and one to save for future generations. But, my concern now is by the time i get to the brew, and the jar i'll save for the future, i'm on generation 5 or 6, built from a low yield. Is there concerns about yeast health here? Or am i overthinking it

 

[CascadesBrewer]

My input would be...

No, there would not be any issues caused by the "multiple generations" of stepping up a starter (assuming your process is solid).

If you are doing it for the joy or challenge of rescuing your harvested yeast, then great! Or maybe it is REALLY hard for you to get new liquid yeast. If not, it might be best just to start with a new pack. I harvest and reuse yeast. It is mostly just common stuff. If it gets to the point where I am concerned about the health of my yeast, I will just dump them and start from fresh. In some cases I might get a dozen batches off one pack...some cases I might just get one or two.

 

[Deadalus]

I regularly store yeasts split off from starters and they are very frequently older than the ~4 months you stated. If I know it's older than about a year I might give it two steps but most times don't. If it's really old pushing about 2 years I would but I might also just go ahead and buy a new pack at that point. Depends on if I thought about it far enough ahead. I'm just about to pitch an at least 8 month old saved yeast into the starter flask.

I oxygenate my wort and most times finish up and pitch in the evening when brewing and it's a rare event to not have visible activity the next morning. My saved yeasts are about 200 ml give or take 50 ml pitched into 1800-2000ml of starter wort.

My condolences on the loss of your father.