Expired Dry Yeast Test - Encouraging result

[PCABrewing]

Back in 2018 I received a packet of SafAle BE-134 (dated 03 2021) that had been punctured by another item in the shipment.
There was a tiny hole that was just large enough for yeast particles to escape so I threw the whole unopened packet into a small zip-loc bag, tossed it into the refrigerator and fired-off a message to the vendor (NB). Because it was punctured and thereby opened to the environment I had no intent to use it, I just planned to save it until the vendor made good on the transaction.
I explained the problem in the message and they promptly sent a replacement, no questions asked.

I forgot about the packet in the zip-loc bag until yesterday when I discovered in in the fridge.
Keep in mind that this packet is six years old. Based on the date it was packaged in March of 2018. Fermentis applies the "best by" date of 36 mos. from packaging.

I was curious if it was still viable so I did a little test.
I dissolved ~1/3 tsp table sugar in a pint-glass of tap water and pitched the yeast. I didn't bother taking a SG because I was not trying to achieve a target, I just wanted to see if it would have any life left in it.
Pitch time was 1500 hrs. yesterday.
At 1700 the liquid was cloudy with a thin film of fine bubbles on the top.
By 1900 there was a obvious krausen forming.
At 0900 today I had a mini carboy fermenting on the counter with typical visible action of rolling clumps of yeast riding the bubbles. Smelled like fermentation without hops.
By 1300 today the activity had mostly subsided. Still curious, I added a little more sugar water.
Sure enough it picked-up again and by 1700 I had a small krausen on the top.
Six Years Old and it still had life in it.

Now I know this wasn't a well-controlled experiment but it made me optimistic that the frequently stated viability wisdom was at least somewhat based in fact.
I wouldn't rely on one of my old packets without having a backup fresh one on-hand, but I am definitely not throwing away any older packets that I know have been stored well.

Cheers

 

[MaxStout]

It's like proofing bread yeast. A little sugar and see if it foams up. This confirms what I hear about dry yeast remaining viable years beyond its best-by date. Apparently the puncture didn't introduce any infection the yeast couldn't out-compete.

 

[BongoYodeler]

Just today as I was putting an order in to MoreBeer I was scrounging around for something helpful for a couple dollars, to get me to the $59 limit for free shipping. I came across expired packs of EC-1118 champagne yeast for 76 cents a pack. I added four pks to my order. They had an expiration date of March 2024, but I'm betting they'll work just fine fermenting future batches of RHL.

 

[MaxStout]

I still have a packet of D47 in the fridge with an expiration of 5/21. I might use it in a batch of EdWort's Apfelwein. I only make 3 gallon batches of that, so should be plenty of live yeasties to do the job.

 

[Clint Yeastwood]

Dry yeast dates seem really pessimistic to me. Not just brewing yeast, but bread yeast.

On a related note, my wife just threw out three bottles of El Yucateco hot sauce from 2021. I can't make her understand that hot sauce lasts forever.

 

[Bramling Cross]

Dry yeast dates seem really pessimistic to me.

They're simple organisms. They don't have brains, let alone personalities.

On topic, contemporary dried yeast is amazing! I ignore best buy dates with regularity. If I see a good deal, I buy big, toss it in the fridge, then use it whenever it's convenient. Sometimes "convenient" is years out of date. So what? It still works.

Edit: Sorry, Yeastwood, I just re-read your post and I get you, now. I thought you meant brewing with dried yeast is dreary. You meant "pessimistic" as cautious. I gotcha, and I agree. Please don't hold it against me, I'm so used to people trying to run down dried yeast...

 

[BrewnWKopperKat]

With regard to 'best by' dates, I currently have the impression that the yeast labs are looking for consistent performance for the duration of the 'shelf life' of the yeast strain.

For example: link to Lallemand article on shelf life (with a PDF download /1/). And from the PDF (the strain is Diamond Lager):

---

/1/ The 'download' button has a 'new to me' language selection. I pressed the download button, the saw this:

​

and clicking on 'English' finished the download.

 

[Clint Yeastwood]

Edit: Sorry, Yeastwood, I just re-read your post and I get you, now. I thought you meant brewing with dried yeast is dreary. You meant "pessimistic" as cautious. I gotcha, and I agree. Please don't hold it against me, I'm so used to people trying to run down dried yeast...

And here I thought you were making a funny.

 

[PCABrewing]

I am pretty sure that you are correct. Given that they are putting forth a three-year pseudo-warranty I think they are treating us pretty well.

 

[PCABrewing]

On topic, contemporary dried yeast is amazing! I ignore best buy dates with regularity. If I see a good deal, I buy big, toss it in the fridge, then use it whenever it's convenient.

Yeah, agree 100%.
When I started there were a handful, not even a full one.
Then came liquid and pretty rapidly they responded to the demand with quite impressive variety, I switched because it seemed like a no-brainier.
Since then dry has expanded the offering with perhaps the benefit of seeing where the liquid has been selling.
I haven't used liquid in ~five years and I probably won't unless I need something special that isn't available in dry.
I realize that behavior may ultimately reduce the variety available in liquid but that is how the market is supposed to work.

 

[Closet Fermenter]

My record on using old yeast was set last year. I ran across a pack of Premier Cuvee yeast that had expired in 2011while I was taking a break from brewing and fermenting. It was a sealed pack, in a ziplock bag, in the refrigerator.
I decided to give it a shot and see if it would still do the job in my peach brandy-wine recipe. I could see no difference between using this yeast and the fresher packs.
It had expired a DOZEN! years ago!!

 

[hotbeer]

I believe the use by date recommended for the dry yeast are based on storing at normal room temperatures. The fact you kept it in the refrigerator means it will go well beyond it's use by date.

Also, it's seems likely to me that the reported number of viable yeast is probably based on what it's expected to be at that future date. Which will explain why most say that the number of viable yeast in a fresh packet of dry yeast is way underestimated.

So even after the use by time is passed, just like many do for liquid yeast, all that it needed is to increase the amount used. Or perhaps make a starter and increase the cell count. However for those of us using dry yeast exclusively, we probably won't be that great at making a starter or have the equipment that the more serious about liquid yeast people have.

And as you mention in your post, it's only a time that it is recommended it be used by. Not that the yeast is expired, as your title claims.

 

[mac_1103]

I believe the use by date recommended for the dry yeast are based on storing at normal room temperatures.

Fermentis:
Storage
For less than 6 months: the product must be stored below 24°C. For more than 6 months: the product must be stored below 15°C. For short periods not exceeding 7 days there is an exception to these rules.
Shelf life
36 months from production date. Refer to best before end date printed on the sachet. Opened sachets must be sealed and stored at 4°C (39°F) and used within 7 days of opening. Do not use soft or damaged sachets.

Lallemand:
LalBrew yeast should be stored in a vacuum sealed package in dry conditions below 4C° (39°F). LalBrew yeast will rapidly lose activity after exposure to air. Do not use 500g or 11g packs that have lost vacuum. Opened packs must be re-sealed, stored in dry conditions below 4°C (39°F), and used within 3 days. If the opened package is re-sealed under vacuum immediately after opening, yeast can be stored below 4C° (39°F) until the indicated expiry date. Do not use yeast after expiry date printed on the pack. Performance is guaranteed when stored correctly and before the expiry date. However, Lallemand dry brewing yeast is very robust and some strains can tolerate brief periods under sub-optimal conditions.

 

[hotbeer]

Fermentis:
Storage
For less than 6 months: the product must be stored below 24°C. For more than 6 months: the product must be stored below 15°C. For short periods not exceeding 7 days there is an exception to these rules.
Shelf life
36 months from production date. Refer to best before end date printed on the sachet. Opened sachets must be sealed and stored at 4°C (39°F) and used within 7 days of opening. Do not use soft or damaged sachets.

Lallemand:
LalBrew yeast should be stored in a vacuum sealed package in dry conditions below 4C° (39°F). LalBrew yeast will rapidly lose activity after exposure to air. Do not use 500g or 11g packs that have lost vacuum. Opened packs must be re-sealed, stored in dry conditions below 4°C (39°F), and used within 3 days. If the opened package is re-sealed under vacuum immediately after opening, yeast can be stored below 4C° (39°F) until the indicated expiry date. Do not use yeast after expiry date printed on the pack. Performance is guaranteed when stored correctly and before the expiry date. However, Lallemand dry brewing yeast is very robust and some strains can tolerate brief periods under sub-optimal conditions.

Let's not confuse the issue with facts!

 

[mac_1103]

Let's not confuse the issue with facts!

"Fact" is such a strong word. Let's just say "recommendations."

 

[PCABrewing]

And as you mention in your post, it's only a time that it is recommended it be used by. Not that the yeast is expired, as your title claims.

Is that your whole issue, that I used the word expired?
To help you sleep at night I hereby wish to issue a correction.

I should have titled this post: "Yeast used after it's 'Best before end date' still made bubbles during a test".

I truly apologize for the anguish that I caused and I hope this correction allows you to understand the point of the post that you were not able to grasp previously.

 

[BrewnWKopperKat]

I believe the use by date recommended for the dry yeast are based on storing at normal room temperatures. The fact you kept it in the refrigerator means it will go well beyond it's use by date.

Also, it's seems likely to me that the reported number of viable yeast is probably based on what it's expected to be at that future date. Which will explain why most say that the number of viable yeast in a fresh packet of dry yeast is way underestimated.

So even after the use by time is passed, just like many do for liquid yeast, all that it needed is to increase the amount used. Or perhaps make a starter and increase the cell count. However for those of us using dry yeast exclusively, we probably won't be that great at making a starter or have the equipment that the more serious about liquid yeast people have.

And as you mention in your post, it's only a time that it is recommended it be used by. Not that the yeast is expired, as your title claims.

"HomeBrewTalk forum wisdom: making dry yeast complicated since, well, forever."

 

[hotbeer]

Is that your whole issue, that I used the word expired?
To help you sleep at night I hereby wish to issue a correction.

I should have titled this post: "Yeast used after it's 'Best before end date' still made bubbles during a test".

I truly apologize for the anguish that I caused and I hope this correction allows you to understand the point of the post that you were not able to grasp previously.

You take criticisms entirely too seriously. You should smile and imagine most anything I say of that type as being friendly picking.

I don't get angry over things other people do to themselves.

 

[PCABrewing]

You take criticisms entirely too seriously. You should smile and imagine most anything I say of that type as being friendly picking.

I don't get angry over things other people do to themselves.

If I imagine it to be so does that make it so?
Oh I surely hope so. I would add that you give criticism too readily. I was simply sharing my positive experience, not requesting feedback.

I didn't get angry, if I had my response would likely/rightly have gotten me booted.

Rather I chose a sarcastic response to call-out the fact that you shifted the focus from the fact that whatever they call the date, my packet was WELL past it and I was encouraged when it responded positively.
Surely you're OK with sarcasm, it's harmless.

 

[PCABrewing]

Peace out (whatever the He__ that means.

 

[mac_1103]

I was simply sharing my positive experience, not requesting feedback.

Well in that case, you probably should have titled the thread "Please do not respond." You'd still have gotten responses of course, but they'd have been different and quite possibly involved goats.

 

[hotbeer]

If I imagine it to be so does that make it so?
Oh I surely hope so. I would add that you give criticism too readily. I was simply sharing my positive experience, not requesting feedback.

I didn't get angry, if I had my response would likely/rightly have gotten me booted.

Rather I chose a sarcastic response to call-out the fact that you shifted the focus from the fact that whatever they call the date, my packet was WELL past it and I was encouraged when it responded positively.
Surely you're OK with sarcasm, it's harmless.

I have no idea what you are imagining. I'm okay with sarcasm of any kind. It's entirely harmless to me.

But like your previous post, this one also has me imagining you are raging and about to have a stroke.

So hopefully I'm just misunderstanding the intent behind them.

 

[Indian_villager]

Dry yeast dates seem really pessimistic to me. Not just brewing yeast, but bread yeast.

On a related note, my wife just threw out three bottles of El Yucateco hot sauce from 2021. I can't make her understand that hot sauce lasts forever.

The date is based on a packaging validation. The date is based on how long they actually bothered to test, or they tested this long and actually found an issue. For a product this cheap, I don't expect them to have done some ridiculous 10 year validation where as they can convince sweaty brew boys to spend another $5. For dry yeast I'm sure you can go way past the date so long as you meet the minimum recommended storage conditions. When the margins are that thin and they have to beat a competitor to market, why wait?