washed yeast - how long can I use them?

If you wash yeast, how long do you reasonably expect to be able to use them?
Not best case, but typical case.

3 months?
4?
5?
6?

When using them, you will certainly want to first smell them.
Do you make a double starter? ( start with a smaller amount of starter, refrigerate, decant, and add more wort? building it up in 2 stages)

Also - if you have stored it for several months, even if a lot of the yeast is less viable, some must be dead. Wont that impact the taste?
Or is it a matter of not using it when it starts to semll bad.

If you make a starter, then the age of a yeast isn't really an issue.

Bobby M did a test on year old stored yeast here; https://www.homebrewtalk.com/f13/testing-limits-yeast-viability-126707/

And my LHBS cells outdated tubes and packs of yeast dirt cheap 2-3 dollars each and I usually grab a couple tubes of belgian or other interesting yeast when I am there and shove it in my fridge. and I have never had a problem with one of those tubes.

I usually make a starter but I once pitched a year old tube of Belgian High Gravity yeast directly into a 2.5 gallon batch of a Belgian Dark Strong, and after about 4 days it took off beautifully.
The purpose of a starter is to reproduce any viable cells in a batch of yeast....that;s how we can grow a starter form the dregs in a bottle of beer incrementally...and that beer may be months old.

Even if you have a few still living cells, you can grow them....That's how we can harvest a huge starter (incrementally) from the dregs in a bottle of some commercial beers. You take those few living cells and grow them into more.

I don't know what you mean by double starters, I make all my starters by building them up incrementally over a few days.

Yeast are cannibals, those that survive will eat those that are dead. You won't notice them.

I've used over a year old jar of yeast with no issues.

I think you are more likely to notice off flavors or drastic changes if you try to push it past 5 generations than you would by using old yeast.

bassbone said:

I think you are more likely to notice off flavors or drastic changes if you try to push it past 5 generations than you would by using old yeast.

Click to expand...

But I assume the older the yeast, the more dead cells, and thus more off flavor?
Or is it such small a quantity that its not important?
Doesnt the autolysis smell come from dead yeast - if they were eaten, wouldn't that smell not be there?

In any case, I will try it with some Mr Beer cans I have lying around.

ArcLight said:

But I assume the older the yeast, the more dead cells, and thus more off flavor?
Or is it such small a quantity that its not important?
Doesnt the autolysis smell come from dead yeast - if they were eaten, wouldn't that smell not be there?

In any case, I will try it with some Mr Beer cans I have lying around.

Click to expand...

Yes. Older will equal more dead cells.

My understanding of autolysis is that it is from letting the beer sit for a really long time on dead yeast after it has fermented out (when even the live cells are dormant).

I think in your case, the fact that the beer will come in contact w/ dead cells when it is most active should let the live cells gobble up the dead ones minimizing any autolysis risk.

If there are any biochemists out there, feel free to chime in if I have this wrong...

Hmm.. this is interesting.

I have some rinsed yeast in my fridge, probably about a year old (maybe more, gotta check my logs) and I was going to make my next batch using the same strain. I just assumed I should go buy new vials, but maybe I'll make a starter and see how it goes...

dunnright00 said:

Hmm.. this is interesting.

I have some rinsed yeast in my fridge, probably about a year old (maybe more, gotta check my logs) and I was going to make my next batch using the same strain. I just assumed I should go buy new vials, but maybe I'll make a starter and see how it goes...

Click to expand...

Yes, make the starter, and let us know how it goes!

Again... LISTEN TO REVVY!!

You can buy dead yeast at LHBS to put in your beer. They are called yeast hulls and are sold as a yeast nutrient.

Also once the starter takes off the yeast are only as old as your starter. You have a brand new bunch off yeast in there that were just budded and the dead ones were all eaten by the new ones.

Age of the yeast doesn't matter in a starter. As was noted above, only the number of times the yeast have been propigated matters. As you reuse (allow the yeast to reproduce) they will slowly mutate. This means after some generations (I've heard anything from 5 to 15) they will stop acting like the original strain and become more of a strain of their own.

TotemWolf said:

Again... LISTEN TO REVVY!!

As you reuse (allow the yeast to reproduce) they will slowly mutate. This means after some generations (I've heard anything from 5 to 15) they will stop acting like the original strain and become more of a strain of their own.

Click to expand...

Let us also be clear that this can be a good thing or a bad thing. I have found that the most common mutation that happens to me after too many generations of WLP001 or Pacman is that the yeast becomes less flocculant.

However I have no doubt that proprietary strains like pacman and bells's strain are the result of mutation of an original strain.

permo said:

Let us also be clear that this can be a good thing or a bad thing. I have found that the most common mutation that happens to me after too many generations of WLP001 or Pacman is that the yeast becomes less flocculant.

However I have no doubt that proprietary strains like pacman and bells's strain are the result of mutation of an original strain.

Click to expand...

+100

Without getting to far off subject into a yeast wrangling dicussion. Old yeast doesn't equal bad yeast. Resused yeast doesn't equal bad yeast. (at most it equals less flacculant yeast)

If washed yeast has been stored under good conditions, I certainly wouldn't hesitate to use it after six months, maybe even longer, especially if making a starter.

question on Autolysis

So when does Autolysis become a problem for Home Brewers?

If autolysis occurs, doenst it cause the yeast to smell bad, and thus affect any beer it comes in contact with?

Is there no downside to washing yeast with respect to dead yeast, provided you make a starter, and possibly step it up? (not counting infections which clearly are a problem)

I have definitely used yeast over 6 months old in the fridge with no off flavors or problems fermenting.