When to get fresh yeast

[m00ps]

I always make a starter and I harvest all my yeast from my starters to re-use for the next batch. I've got a few strains in particular that Im worried about whether ive gone too many generations with them. I dont detect any noticeable changes in characteristics, and I would think that growing them in clean 1.040 wort each time wouldnt change them much. But at the same time, I've over 10 generations with 2 or 3 of them

What do you guys think? Should I buy new yeast or just keep on truckin

 

[dinnerstick]

i say keep truckin. as soon as you get nervous or think you've got something wrong, chuck it and start over. but if it's all good then it's all good!

 

[aryoung1980]

I vote keep going too. Who knows, maybe they'll slowly mutate and become something better. At least that's what I'm hoping for with my WLP004, WLP940, and US-05. I'm not over ten generations yet but as long as they're doing what I want I'm running them as far as possible.

 

[Natdavis777]

I wash mine, so Im only going 3 generations for each strain. This still allows me to harvest a crapload of yeast (10gal batches) without running the risk (hopefully) of mutating the strain.

 

[IslandLizard]

Start yeast ranching, by making a slightly larger starter each time and saving some out when pitching. You'll always have 0-gen yeast that way.

 

[bja]

I've been reusing the same yeast for over 2 years and it seems to be getting better and better.

 

[aryoung1980]

Start yeast ranching, by making a slightly larger starter each time and saving some out when pitching. You'll always have 0-gen yeast that way.

Every starter counts as a generation.

 

[m00ps]

Start yeast ranching, by making a slightly larger starter each time and saving some out when pitching. You'll always have 0-gen yeast that way.

This was my thinking too. Since you are putting them in optimal conditions without hop compounds and like specialty malts I figured stress on the yeast would be minimal

 

[aryoung1980]

There is less stress but you're still creating new yeast which is a new generation.

 

[MrE_the_Great]

I've gone 5 or 6 generations without issue. Some of those have been ranched with a starter, some have been washed only to be ranched the next time. I've even stored them in the fridge for multiple weeks between brews and I still think things are good with them. One strain I even pitched directly on the cake and then washed for the next time. Experimenting is one of my favorite parts of this adventure.

Sanitize, sanitize, sanitize...

 

[giraffe]

I usually get a fresh sample after 6-8 generations on most yeasts, but I harvest out of the bottom of the fermenter, which is sloppier than doing it from the starters. That said, i cant say ive noticed much difference from gen 2 to 8, ever, (not to say that there wasnt, its hard to tell as im not making identical beer over and over, but nothing tragic). Supposedly floculation/attenuation changes are usually the first noticeable genetic drift.

But its only 7$ or so for a fresh yeast sample. Unless its a rare strain, id think after 10 generations youve made it cost effective. Id only keep going if you are interested in it as an experiment.

 

[AnOldUR]

Just my experience, but I've been harvesting from my primary fermenter and pitching a measured amount of slurry (no starter) for a long time. After the 12th generation of a recent harvest I got nervous and bought new. No detectable off flavors, I just thought it was time. As an experiment, I made a 10 gallon batch and pitched 5 gallons with the new yeast and 5 gallons with the 12th generation. Both at as close to the same cell count as I could come without a microscope. Pitch one evening and had identical krausen on both by morning. Visually, both fermentations were identical. Did identical dry hops in both. The 12th generation finished at 1.010 and the new stuff at 1.011. Even having my wife switch things up without me looking, I can't tell the difference in flavor or aroma.

Brewed last weekend and pitched the 13th generation. Couldn't bring myself to toss it. :cross:

 

[55x11]

Interesting thread. What is the longest you would keep a harvested yeast in the fridge and still not worry about re-pitching it? A year?

Does anyone freeze their yeast - Whitelabs Yeast book says the yeast has to be super-healthy and full of nutrients - does it mean freezing from the starter?

 

[Natdavis777]

Ive made starters with harvested yeast that was in the fridge for 6 months. I ended up pitching 150mL of compacted slurry in the starter though to account for decreased viability. Beer turned out great!