Dry yeast life in the fridge?

[fatjay]

Does it expire/die? I bought about 20 packs of ec1118 and stuck them in the butter shelf in the fridge, but it's been a couple months. How long will they be viable?

 

[Miraculix]

About 5 to 10 years. Put them in the freezer and they will store almost forever.

 

[mac_1103]

How long will they be viable?

A lot longer than your refrigerator.

 

[BrewerofBeers]

Yeast companies hate this one weird trick!

(photo of beer yeast on butter shelf).

 

[Willy]

If you are over 60....
Odds are ... You will die before the yeast does. Never do a term life policy on yeast.

 

[betarhoalphadelta]

Let me rephrase the question on behalf of @fatjay ...

How quickly will the viability drop off over time in the fridge such that you can still avoid making a starter?

I.e. the yeast won't all die, but I assume there is a predictable dropoff curve such that after some time has passed, it's not going to be an appropriate pitch volume of viable yeast for your brew...

Maybe that answer is also "years" rather than months, but that's the version of the question I'd want answered.

 

[Miraculix]

Let me rephrase the question on behalf of @fatjay ...

How quickly will the viability drop off over time in the fridge such that you can still avoid making a starter?

I.e. the yeast won't all die, but I assume there is a predictable dropoff curve such that after some time has passed, it's not going to be an appropriate pitch volume of viable yeast for your brew...

Maybe that answer is also "years" rather than months, but that's the version of the question I'd want answered.

That's what my above answer is referring to.

 

[mac_1103]

How quickly will the viability drop off over time in the fridge such that you can still avoid making a starter?

Doesn't change the answer.

 

[wsmith1625]

and stuck them in the butter shelf in the fridge

Mine go in the deli drawer

 

[BongoYodeler]

Mine go in the deli drawer

Salami stout?

 

[BrewnWKopperKat]

How quickly will the viability drop off over time in the fridge such that you can still avoid making a starter?

If you are looking for data, this Fermentis presentation (2017, link to PDF) may be of interest.

 

[betarhoalphadelta]

If you are looking for data, this Fermentis presentation (2017, link to PDF) may be of interest.

Thanks! Very helpful. I don't think I'm going to let anything age 4+ years so I should be good to go

 

[Pennine]

If you are looking for data, this Fermentis presentation (2017, link to PDF) may be of interest.

Interesting, basically it lasts forever.

 

[BrewnWKopperKat]

Interesting, basically it lasts forever.

For practical values of 'forever', that seems to be generally true; although the chart on slide 13 hints at it being SKU specific.

... and then there's slide 26 (performance of aged yeast based on storage temperature).

Some recent anecdotal stories from experienced brewers on failed starts from certain yeast products could cause one to suspect this data is specific to a brand (or perhaps the quality of the yeast drying process).

 

[SFC Rudy]

I’ve used yeast 2-1/2 years after expiration, so at least 2-1/2 years.

 

[Closet Fermenter]

I’ve used yeast 2-1/2 years after expiration, so at least 2-1/2 years.

I used one of this very strain that was 10 years past expiration. It had been kept in the refrigerator since purchase. I poured it in a 3 gallon batch directly from the package and it was working within an hour.
To be honest, I had a fresh pack as backup, but since these little yeasties had been waiting patiently in the cold for years to do their thing, I just thought it too cruel to deny them the opportunity.

 

[Steveruch]

I’ve used yeast 2-1/2 years after expiration, so at least 2-1/2 years.

I used a Muntons over four years past it's best by date in three gallons of bitter with no issues.

 

[MaxStout]

A few variables include how the yeast was treated from the HBS to the buyer. Does the HBS keep it refrigerated? I think most do, but I've seen a few shops where dry yeast is kept on room temp shelves. Did the yeast endure a trip in a hot truck en route to the customer? A few days of that can significantly reduce viability. If your yeast arrives damaged, all the refrigeration in the world won't help it.

 

[dmtaylor]

I like the slide where they show viability is better if stored at 5C than if stored at -20C.

 

[Pennine]

I like the slide where they show viability is better if stored at 5C than if stored at -20C.

Yep that was the takeaway, put your dry yeast in the refrigerator and don't worry about the use by date.

 

[Zadkiel]

Interesting chart on page 21 of the fermentation rate of fresh vs aged 34/70 - the graph isn't 0-indexed (one of my pet peeves, and they only do it on this one slide for some reason which makes it worse), so the change isn't as high as the chart visual would make you think, but it's still pretty significant.