Liquid Yeast Arrived Warm. Can it be salvaged?

[nyrmc23]

I placed an order from Northern Brewer Aug 15 and it arrived today. I don’t know how long the White Labs English Ale was in the box for, but it and the cooling packet arrived very warm.

I requested a refund but was told it should still be good. I have it in the fridge now. Thoughts?

 

[3 Dawg Night]

Make a starter. If it takes off, you're good to go. If not, contact NB and tell them that was, in fact, not still good.

 

[AJinJacksonville]

Agreed with 3 Dawg. You'll find out pretty quickly if it still good with a starter.

Either way, I'd still contact them...especially if you paid extra for the ice pack.

 

[Maxkling]

This is why you should always keep a few dry options as back up. He might not have the equipment or materials for a starter. I’d just pitch as you planned and hope for the best. Go ahead and order some dry yeast and maybe it will arrive in time for a backup plan if fermentation never starts.

Chances are you will be fine.

 

[Maxkling]

FYI you can get a pack less than 5$ on Amazon by Thursday or Friday.

 

[DVCNick]

I've had several liquid yeast packs arrived very hot and all three were fine with a starter. Chances are you're fine... but that is why they put the disclaimer on the website to order liquid yeast in the winter.

 

[mashpaddled]

Yeast naturally exist in warm conditions. If it's hot outside where you live then there are yeast living in hot conditions all day long every day. Yeast don't suddenly die from warmth. Certainly the inside of a semi is a lot hotter than the open air under a tree but yeast don't start dying until they hit much warmer temperatures and it doesn't happen overnight. If you are at all concerned make a small starter to test viability. If it ferments then you are good to go.

 

[Iowayankees]

Happen to order the same with the ice packs. Brewed 10 gallons Mocha Porter and my first yeast starter. 5 gals with the starter bubbled nicely after 24 hours. The other 5 gallons using the same packets not used in a starter sat for 72 hours without activity. Last night I rehydrated 04 dry packets. 12 hours later fermentation is seen thru the airlock! Lessons learned on yeast starter and not wasting money on ice packs and liquid yeast in the summer. Cheers!

 

[deuc224]

Ill be the dumb guy here and was drinking while making a NEIPA and pitched my yeast into the fermenter when the wort was reading at 88.1. Thought it was gone for sure until i woke up the next morning and the star san jar was bubbling hard! I guess yeast isnt as fragile as we all make it seem.

 

[balrog]

I have received WYeast packs warm and slushy-frozen. They have never failed to start, but I do always make a starter a few days before planned brew day.

 

[Dancy]

I placed an order from Northern Brewer Aug 15 and it arrived today. I don’t know how long the White Labs English Ale was in the box for, but it and the cooling packet arrived very warm.

Two nights ago, I brewed an Irish Red Ale, 5G, and used a pack of Wyeast 1272 American Ale II that was shipped to me in Minneapolis from Atlantic Brew Supply in SC. I ordered 2 extra ice packs in addition to the one included. It arrived days later at about room temperature. I pitched It two nights ago, no starter, into my oxygen treat wort. I never make a starter and no issues but usually use the larger Imperial yeast pack — lesson learned. By mid morning yesterday, there was no airlock activity yet — not the end of the world — but when I pushed on the side of my Speidel fermenter, there was clearly zero pressure built up as the airlock did not move at all after pressing hard on the plastic fermenter. I had a packet of Windsor British Ale yeast which I rehydrated and pitched and within a couple of hours pressure was building and by late afternoon it was bubbling away. Usually I purchase Imperial Yeast (more cells) locally but it was easier to include the Wyeast with my grain order. Heed the summer heat warning!

EDIT - I used BeerSmith for the first time and based on my yeast pack’s date, it stated the viability at 65%.

 

[IslandLizard]

Wow, 10 days in transit in the midst of Summer!
Yeast cells die, not due to just the heat, but in combination with a lack of food.
They wake up from their chilled, dormant state but with very little or no sugars available to metabolize.
Most yeast fair well at higher temps, up to around 100-110F, as long as they have nourishment.

I'd definitely make a starter:
a) To prove viability
b) Ramp up cell count
c) Perhaps save some out to make another starter from next time

BrewUnited's Yeast Calculator
Mr. Malty

 

[IslandLizard]

Anyone who thinks that those ice packs are still frozen and protect your yeast after more than 12 hours at even moderate ambient temps during transport, should try this experiment:

Re-freeze one or 2 of those (small) ice packs. Then stick into a bubble envelope, seal with tape, then lie it on the kitchen counter. Or stick the envelope into a box together with a bag of grain, as if buying a kit/supplies from NB, MoreBeer etc.
Check after 6 hours, if not totally soft yet, check again, 6 hours later. Now you know!
A warehouse or truck can be a lot hotter than that, while 12 hour deliveries are extremely rare!

If anything, the bags of ice (water) function more or less as a temperature buffer in the micro-climate of the bubble envelope/box.

Liquid yeast really shouldn't be shipped during seasons with extreme temps along the route. Instead, stock up by getting them shipped during cool and moderate temps. And always make starters, for reasons I mentioned in the post above!

 

[3 Dawg Night]

Instead, stock up by getting them shipped during cool and moderate temps.

So, what's the consensus on how long you can store liquid yeast before using it? Can I stock up for the year in, say, February, and let that carry me until November? Here in Alabama, we can have hot temperatures starting in March or April and lasting until late October!

Will a liquid yeast pack still be good 8-9 months after purchase? (I know, make a starter to be sure.)

 

[IslandLizard]

So, what's the consensus on how long you can store liquid yeast before using it? Can I stock up for the year in, say, February, and let that carry me until November? Here in Alabama, we can have hot temperatures starting in March or April and lasting until late October!

Will a liquid yeast pack still be good 8-9 months after purchase? (I know, make a starter to be sure.)

White Labs' Purepitch sleeves fare better with time than any other packaging. Only 10% degradation (loss of viability) over the first 3 months. That's only 3% per month vs. 10% per month for any other packaging. Viability declines by about 10% per month after that, pretty much as any other yeast, but you start at 90% after 3 months, instead of 70%.

I've successfully revived 3 year old yeast stored in the fridge, in original packaging, and just as successfully from saved-out starter slurries. Not saying it's the best method, making starters well before they're a year old is much easier and better.

When we receive our yeast it's usually 2-4 months old already. Sadly, that seems to be a fair average, I read that somewhere. Therefore, one should always making a starter before pitching, but more so when they're a few months old.

If you know they're not going to be used within 2-4 months after receiving, I'd make starters with those and save the crashed slurries in 4 oz or 8 oz mason/jelly jars in the fridge. The 10% decline per month clock gets reset and starts ticking down from there on. That extends their life span another 6-12 months (or longer). With good sanitation that renewal process can be repeated quite a few times.

I had an old fashioned vial (not a Purepitch Pack) of Yeast Vault yeast sent to me from White Labs (San Diego) in March last year. There were medium hot days along the southern route it took (on a USPS truck). It was slightly warm when I received it and it took a while to make a decent starter from it.
https://www.homebrewtalk.com/threads/white-labs-wlp546-marañón-canyon-wild-cacao.662582/post-8558608

 

[3 Dawg Night]

White Labs states that their QC process requires 95% viability before it leaves their facility, and they state that their yeast only loses 3.2% viability each month (citation). Based on that, it should take 15 months before you're even below 50% viability. I doubt it's truly linear, though. I would bet that somewhere between 6-12 months, viability starts dropping more aggressively. I haven't found any research to back that up, though.

 

[IslandLizard]

White Labs states that their QC process requires 95% viability before it leaves their facility, and they state that their yeast only loses 3.2% viability each month (citation). Based on that, it should take 15 months before you're even below 50% viability.

Don't we all wish that were true...
It's what they wrote, but it's also very misleading (deceptive) since they left month 6 out of that calculation.
From your (linked) page, here's what their data indicates:

Average viability of PurePitch® pure liquid yeast over a period of six months:

Time	Viability
1 month	99.21%
2 month	98.05%
3 month	90.26%
4 months	84.28%
5 months	79.35%
6 months	71.59%

That data (above) shows that the 3.2% decline in viability per month is only valid for the first 3 months.

At month 6 (71.59%) decline in viability is much closer to 10% (9.82% actually):

79.35% - 71.59% = decrease of 7.76% (compared to and down from 79.35%)​

7.76/79.35 = 9.82% drop in viability from month 5.​

​

 

[3 Dawg Night]

@IslandLizard I wasn't saying it was true! I was just too lazy to tease out the math. Now you made me go and do it.

If you fit a 2nd order polynomial to the data and extrapolate from there (trained statisticians can stop reading now), it shows that you'll hit 50% viability somewhere around 8 months, and 0% viability somewhere around 12 months.

I have no idea how accurate that is, but it's not unreasonable. Without better data, it supports your original recommendation of stocking up for the year during the cooler months. As long as you use it within 8-9 months, you should have at least 50% viability, but it will drop off significantly after that.

Has that been your experience?

 

[IslandLizard]

Has that been your experience?

With the Purepitch sleeves I'd expect around 50% viability left after 8-9 months, yes. For all others, around 15-20%.
0 viability is unlikely after only a year, there are always a few cells that live through, unless she was cooked or stored for a few years on your back porch.

I've resurrected yeast slurries that were over a year old, 100-120 billion cells at the time of saving out, 6% viability after a year in the fridge. In just 2 steps (250ml and 1500ml @1.037) they were at pitchable amounts of around 250 billion cells (est.) Takes about 8-10 days in total, with a cold crash in between. They looked good and healthy, behaved as expected when pitched.

I tend to use BrewUnited's yeast pitch calculator for the easy and clear interface and automatic multi steps. For healthy yeast packs and slurries I rarely need to do multiple steps, I try to avoid them due to the extra time involved. But it happens.

 

[bwible]

I've successfully revived 3 year old yeast stored in the fridge, in original packaging, and just as successfully from saved-out starter slurries. Not saying it's the best method, making starters well before they're a year old is much easier and better.

I have used Wyeast packs that were 2-3 years old several times. Made up a starter and they were fine.

I had an old fashioned vial

I remember those old White Labs vials. I was told they were actually 2 liter soda bottle blanks before they were put on the machine and expanded. They were very durable,

 

[brewpharm Hill]

FWIW I've had liquid yeast arrive and sit in my entryway in mid August in high 90 degree weather. Creating a starter has never been an issue to revive and still made beer without any off flavors and poor fermentation that I could see/taste.