Oversize yeast starter

[Mathomson75]

Ok so basically I'm looking for a definitive answer. What I have been doing with my liquid yeast strains due to lack of a nearby supplier is I have been making a bigger starter than needed making it 1qt larger on my stir plate then when it's done I jar that quart and use tge rest of my yeast for my beer. I then use that quart on my next starter and repeat the process. I have done this probably 15+ times on my oldest strain and haven't noticed any off flavors yet. My main question is their a limit to how many times you can do this or is their any other adverse affects?

 

[Summers]

I recall reading an article that after 4 or 5 times the yeast strain has started to mutate from the original strain, however I can not find the article again as a reference. Then again I have used a few different strain more than the 4-5 times and I have not had any problems. So say keep using it and by now I would call it your house yeast.

 

[Brentk14]

This is exactly what I do, and I haven't had any off flavors either. I make my oversize starters at 1.035 on a stir plate and do the best I can to keep them from any infections. I have done a lot of reading about lifespan of yeast, and a lot of info says 4-5 times and they are done, but I would say that is under brewing conditions, where normally beer is over 1.060, and it stresses the yeast out more.
I am probably wrong, but that's how I justify it. lol

 

[jpakstis]

I've harvested overbuilt starters going on 18 months now and I've made 6 batches with US05 and if there is a difference I haven't tasted anything.

I make 1.5Lstarters (because it's easy to remember that 100g of DME into 1L is 1.040 gravity), add a 1/4 tsp of yeast nutrient, probably out of habit than anything else, and let it sit on the stir plate until brew day, which is usually 4-5 days later.

Then I harvest an 8 ounce mason jar's worth (about 240 ml) and pitch the rest. I used to cold crash and decant but I have found that I prefer to have the extra day to build up the starter than to cold crash it. It's worked out great so far!

 

[LLBeanJ]

There's no definite answer. Unless you're doing your yeast culturing in a lab environment, the strain will mutate over time and possibly be overcome by a wild strain before that happens. My practice is to keep using it until it turns into something I no longer like.

 

[IslandLizard]

If your sanitation is impeccable, there's no real limit. But each round you'll undoubtedly pick up some other microflora, which after a few generations of starters may show their presence.

 

[Mathomson75]

The only one I have noticed a possible change with is the wyeast 1068 seems to have more banana notes the last couple batches. the 1056 has done at least 15 and It is still making great beer. maby I'll try swapping them out every 6 months or so I really only keep about 3 strains on hand. And I can get to th e brew shop every other month or so.

 

[IslandLizard]

There is no 1068. Do you mean 3068 or 1968?

3068 is a German wheat beer yeast, and will give off banana and clove, depending on fermentation temps.

There should not be any banana esters from 1968 (ESB), if so, you may have some mutation on hand there.

I'd say 3-5 starter gens should be fine. Actual age may play a role too.
I noticed my 2 year old reused 1968 (ESB) culture wouldn't clear anymore, kept hazy for weeks, months. Using a starter from a fresh pack, it dropped clear in 2-3 days.

 

[Mathomson75]

Sorry I meant 3068 typo just seems to be giving off more banana esters at the same term temp