Harvested yeast shelf life

[drhookmec]

How long should harvested yeast be good for?

I've had some that where like 6-months old and
worked great with a good starter and fermented out perfectly.

Others i've dumped cause they where a year old and it looked like something was growing on the bottom of the jar.
Any one else notice this with old harvested yeast?

 

[scottland]

<2wks, and you don't even need to make a starter.
>2wks and you should make a starter.

As for how long it can last in the fridge? 6 months is probably about as long as I'd want to go. Basically it's the % of viable cells that drop. Day 1 you're at like 95% viable cells. After 2wks it's still probably around 80%. 6 months later there might be around 5-10% of the yeast cells that are still viable. So you'll need to step up the yeast to get to a pitch.

 

[plumbob]

You'll want to get a starter going from old yeast before you pitch. Should still be viable with some care.

 

[JohnnyO]

I couldn't imagine ever pitching washed yeast without making a starter. Maybe it's just me.

Without making a starter, there is no way you have enough viable yeast to pitch.

 

[Revvy]

If you make a starter, then the age of a yeast isn't really an issue. When you make a starter, and grow it, you're replicating more yeast to make up for any loss. You're making new, fresh yeast.

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And my LHBS cells outdated tubes and packs of yeast dirt cheap 2-3 dollars each and I usually grab a couple tubes of belgian or other interesting yeast when I am there and shove it in my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.

 

[drhookmec]

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.

REV funny that you mention this as i have successfully cloned a
bed of yeast from a Budweiser.

Have not used it yet but i believe it will work
with a good starter.

tim

 

[insubordinateK]

As long as you can keep it uncontaminated, you can use it for years.

 

[drhookmec]

As long as you can keep it uncontaminated, you can use it for years.

I only wish this was true but there is a cut off as to when the yeast gets to old
even when kept at proper temp.

My educated guess is 1yr now anyone else with some experience in
doing this i'd like to here your input.

tim

 

[insubordinateK]

I only wish this was true but there is a cut off as to when the yeast gets to old
even when kept at proper temp.

My educated guess is 1yr now anyone else with some experience in
doing this i'd like to here your input.

tim

It is true, as revvy pointed out earlier.

I just posted a study on this. Where do you get your information?

https://www.homebrewtalk.com/f128/nice-study-re-pitching-yeast-284845/

 

[drhookmec]

My info comes from experience.

Because you can't believe everything you read.

 

[insubordinateK]

My info comes from experience.

Because you can't believe everything you read.

Especially when it's scientific data! Dude, it's just useful information to put in your back pocket. Numbers instead of anecdotes. I figured a dr. would appreciate that.

 

[MrManifesto]

My info comes from experience.

so did his?

 

[Batinse]

My last two batches were started from year-old (actually 13-month-old) washed yeast cultures. That was about the limit of what I was previously willing to try, but my LHBS was out of Kölsch yeast and I really wanted one so I made it out of a 250-mL jar sample (with starter, obv). The beer is totally clean and good.

The second was a Whitbread 1099 sample that I pulled out when I realized I needed a yeast sample for a partigyle. I haven't tasted the beer itself yet, but the starter was clean and active. I probably wouldn't have risked either situation if they weren't already marginal (I had the Kölsch ingredients and so took the risk, and since the other one was a partigyle stout from an RIS, I figure I had nothing to lose) but now, since I haven't noticed any shortcomings, I won't hesitate to do it again.

 

[drhookmec]

Especially when it's scientific data! Dude, it's just useful information to put in your back pocket. Numbers instead of anecdotes. I figured a dr. would appreciate that.

As i do.
Don't take what i said the wrong way
i appreciate anyone responding to my post as the more usefull infomation
we share the better we become.

Believe me NO offense was ment.

tim

 

[insubordinateK]

As i do.
Don't take what i said the wrong way
i appreciate anyone responding to my post as the more usefull infomation
we share the better we become.

Believe me NO offense was ment.

tim

Absolutely. Information is a good thing.

Cheers.

 

[OHIOSTEVE]

I have washed yeast and stored it over a year ( close to 13 months) I made starters and using a stir plate got them going just fine. I did NOT boil the bottles but I did completely submerge them in starsan and I DID boil and cool the water I used to wash it. I also made sure when I filled the bottles they were running over so when they were capped ( beer bottles) there was zero head space. Put em in a fridge and left em until ready to use. I am drinking 2 of the beers right now made with them and am ready to bottle 2 more.
I have done this with s-05...s-04...and notty. I have only ever had one bottle that went bad and that was a bottle of s-04 that smelled rotten when I opened it. i didn't even try it. I am no expert but so far when I open em up and they smell like beer, they are fine.

 

[OHIOSTEVE]

revvy... I just read a LITTLE of the thread you linked to where bobby m did the viability test. You asked a question about the yeast turning grey. I use small corona bottles when I can get em and you can see the yeast layer from the sides. I have noticed that the top layer will turn brownish grey sometimes but if you look from the side there is still a layer of white yeast and those so far have all started fine for me. The one that I dumped was ALL brown and as bobby said it had the puke factor going. The smell was pretty bad. NO WAY was I gonna taste it.

 

[Salmonhouse]

Good Info guys.

+1 on making a starter on old yeast.

I have used harvested yeast after weeks in the frige and I got some poor attenuation because of it. I always make a starter of it now.

 

[OHIOSTEVE]

I just checked the gravity on a batch of oatmeal stout that I have going with some OLD washed and started s-04...it has been in the fermentor almost a month and it is about 6-9 points high depending on which sofgtware you use.

 

[DeadNutsBrewing]

I've used the Wyeast smack packs that were over 2 years old. I smacked it, then waited. It took about 10 days but it swelled. I made a starter and it worked perfectly

 

[bbbrew]

I've used the Wyeast smack packs that were over 2 years old. I smacked it, then waited. It took about 10 days but it swelled. I made a starter and it worked perfectly

What does perfectly mean to you?

 

[DeadNutsBrewing]

By that I mean it fermented out completely with no off flavors.