Liquid yeast viability.

Share your experiences of using brewing yeast.
Paddington
Piss Artist
Posts: 152
Joined: Tue Nov 14, 2017 8:07 pm

Liquid yeast viability.

Post by Paddington » Tue Jun 05, 2018 1:25 pm

https://www.whitelabs.com/news/purepitch-shelf-life

I have a five month old White Labs Pure Pitch which I will be using in a Saison shortly. I've looked at various calculators which give me viability of 0 (Malt Miller), 1% (Brewer's Friend) and 50% (Beer Smith). I've then found the above link from White Labs which claims viability of over 79%. I'm tempted to go with Beersmith but I'd be interested to hear from the old hands...

Fil
Telling imaginary friend stories
Posts: 5229
Joined: Sun Oct 16, 2011 1:49 pm
Location: Cowley, Oxford

Re: Liquid yeast viability.

Post by Fil » Tue Jun 05, 2018 8:31 pm

as long as you step up to a reasonable starter volume ensuring that all sugars are exhasted after each step up before adding more volume/sugar you should build up a full population for pitching. once the final steps additions are exhausted you can simply keep the population dormant in the fridge.
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

Paddington
Piss Artist
Posts: 152
Joined: Tue Nov 14, 2017 8:07 pm

Re: Liquid yeast viability.

Post by Paddington » Tue Jun 05, 2018 10:50 pm

Yes, the problem is that if I go with Brewer’s friend I have multiple steps starting at 200ml, if I go with Beersmith, I can probably do it in one step.

User avatar
IPA
Under the Table
Posts: 1279
Joined: Wed Dec 07, 2011 9:29 am
Location: France Gascony

Re: Liquid yeast viability.

Post by IPA » Wed Jun 06, 2018 6:26 am

Paddington wrote:
Tue Jun 05, 2018 10:50 pm
Yes, the problem is that if I go with Brewer’s friend I have multiple steps starting at 200ml, if I go with Beersmith, I can probably do it in one step.
Two steps will do it 200 ml then 1000 ml . I am old enough to remember when 500ml was the recommended starter size :lol: but that was before the Americans took over the driving seat. Never had any problems probably because nobody had a microscope. I brew 50 litres and never have a starter bigger than 1200 ml although Whitelab say I should be using three of their purepitch sachets.(cost £21) But there again they are selling and I am buying. I am presently fermenting 50 litres with a WLP 037 that I bought in 2013 and have reused at least twenty times.
"You're not drunk if you can lie on the floor without holding on." Dean Martin

1. Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in sideways, thoroughly used, totally worn out and loudly proclaiming... "f*ck, what a trip!"

Paddington
Piss Artist
Posts: 152
Joined: Tue Nov 14, 2017 8:07 pm

Re: Liquid yeast viability.

Post by Paddington » Wed Jun 06, 2018 6:46 am

Thanks, IPA. When I was first started brewing, I just followed recipes without any thought or knowledge of pitching the right amount of yeast and always had good results. As I have learnt a little bit more, I know that I must have been underpitching by some amount according to the calculators, so I am a touch sceptical about it all. I have a 5 litre brew happily fermenting from a few mls of yeast which is over a year old with no starter (I just wanted to clear some space so thought I’d do it as an experiment). What do you think about the viability issue? 1% or nearly 80% as claimed by White Labs?

Rob_85
Tippler
Posts: 14
Joined: Thu Sep 27, 2018 10:04 pm

Re: Liquid yeast viability.

Post by Rob_85 » Fri May 22, 2020 10:40 am

Hello,
Resurrecting this post as I have a very similar question.

I have some liquid yeast manufactured in January (Imperial yeast, so theoretically they are double packs as they apparently start at 200 billion cells). I won't be able to brew with these until at least August maybe even September, so they be 8-9 months old by then.

Will these packs be entirely dead by then or is there still hope? Will stepped starters be enough to bring them back to life? If stepped starters work for me, can I expect to get enough viable yeast for say 1065 wort?

As the OP said the various calculators give wildly different results from their viability calculators.
Any with experience stepping up starters with old liquid yeast, I'd like to hear your thoughts please!

Cheers,
Rob

Digby
Piss Artist
Posts: 122
Joined: Sun Jan 12, 2014 8:54 pm

Re: Liquid yeast viability.

Post by Digby » Sat Jun 06, 2020 7:14 pm

Hi Rob,

I overbuilt a starter of WLP830 in January, and a 500ml jar of this has sat in the fridge until 2 days ago. Made a 1 litre starter on the stir plate, and all seems well.

I will step up to 2.5 litres tomorrow, and when that is done decant 500ml into another sterile jar and back in the fridge before stepping the rest up to 5 litres. I will then have another jar of WLP830 available for next time.

I will probably only do this a few more times before renewing, but all good so far. So, if yours has been kept in the fridge it is likely to be fine if shown a little love.

Matt

Sent from my SM-G955F using Tapatalk


McMullan
Drunk as a Skunk
Posts: 979
Joined: Tue Jul 14, 2015 7:48 pm
Location: Here

Re: Liquid yeast viability.

Post by McMullan » Sun Jun 07, 2020 9:53 am

Liquid yeast die at a rate, dependent on storage conditions. No calculator factors in 'Rob's fridge' and whatever happened before he received the pack. A bigger pack just means more yeast cells have been dying over time, all things being equal. Ironically, we might be better off buying smaller packs generally.

richard080561
Piss Artist
Posts: 122
Joined: Thu Jan 21, 2016 12:02 am

Re: Liquid yeast viability.

Post by richard080561 » Sun Jun 07, 2020 8:58 pm

Rob_85 wrote:
Fri May 22, 2020 10:40 am
Hello,
Resurrecting this post as I have a very similar question.

I have some liquid yeast manufactured in January (Imperial yeast, so theoretically they are double packs as they apparently start at 200 billion cells). I won't be able to brew with these until at least August maybe even September, so they be 8-9 months old by then.

Will these packs be entirely dead by then or is there still hope? Will stepped starters be enough to bring them back to life? If stepped starters work for me, can I expect to get enough viable yeast for say 1065 wort?

As the OP said the various calculators give wildly different results from their viability calculators.
Any with experience stepping up starters with old liquid yeast, I'd like to hear your thoughts please!

Cheers,
Rob
If you put the pack in the freezer now then there when you come to brew there will be as many live yeast cells as there are now.
Richard M
Cardiff

McMullan
Drunk as a Skunk
Posts: 979
Joined: Tue Jul 14, 2015 7:48 pm
Location: Here

Re: Liquid yeast viability.

Post by McMullan » Sun Jun 07, 2020 11:11 pm

richard080561 wrote:
Sun Jun 07, 2020 8:58 pm
If you put the pack in the freezer now then there when you come to brew there will be as many live yeast cells as there are now.
#-o

Digby
Piss Artist
Posts: 122
Joined: Sun Jan 12, 2014 8:54 pm

Re: Liquid yeast viability.

Post by Digby » Sun Jun 07, 2020 11:24 pm

richard080561 wrote:
Rob_85 wrote:
Fri May 22, 2020 10:40 am
Hello,
Resurrecting this post as I have a very similar question.

I have some liquid yeast manufactured in January (Imperial yeast, so theoretically they are double packs as they apparently start at 200 billion cells). I won't be able to brew with these until at least August maybe even September, so they be 8-9 months old by then.

Will these packs be entirely dead by then or is there still hope? Will stepped starters be enough to bring them back to life? If stepped starters work for me, can I expect to get enough viable yeast for say 1065 wort?

As the OP said the various calculators give wildly different results from their viability calculators.
Any with experience stepping up starters with old liquid yeast, I'd like to hear your thoughts please!

Cheers,
Rob
If you put the pack in the freezer now then there when you come to brew there will be as many live yeast cells as there are now.
I am not an expert in yeast health, but I am sure it is not a good thing to have liquid yeast in the freezer. Slants maybe, dry yeast poasibly but not liquid yeast vials in my experience. Happy tp be told otherwise though as every day is a school day.

Matt

Sent from my SM-G955F using Tapatalk


richard080561
Piss Artist
Posts: 122
Joined: Thu Jan 21, 2016 12:02 am

Re: Liquid yeast viability.

Post by richard080561 » Sun Jun 07, 2020 11:34 pm

Digby wrote:
Sun Jun 07, 2020 11:24 pm
richard080561 wrote:
Rob_85 wrote:
Fri May 22, 2020 10:40 am
Hello,
Resurrecting this post as I have a very similar question.

I have some liquid yeast manufactured in January (Imperial yeast, so theoretically they are double packs as they apparently start at 200 billion cells). I won't be able to brew with these until at least August maybe even September, so they be 8-9 months old by then.

Will these packs be entirely dead by then or is there still hope? Will stepped starters be enough to bring them back to life? If stepped starters work for me, can I expect to get enough viable yeast for say 1065 wort?

As the OP said the various calculators give wildly different results from their viability calculators.
Any with experience stepping up starters with old liquid yeast, I'd like to hear your thoughts please!

Cheers,
Rob
If you put the pack in the freezer now then there when you come to brew there will be as many live yeast cells as there are now.
I am not an expert in yeast health, but I am sure it is not a good thing to have liquid yeast in the freezer. Slants maybe, dry yeast poasibly but not liquid yeast vials in my experience. Happy tp be told otherwise though as every day is a school day.

Matt

Sent from my SM-G955F using Tapatalk
I'm obviously not an expert either :D The OP should ignore what I said
Richard M
Cardiff

McMullan
Drunk as a Skunk
Posts: 979
Joined: Tue Jul 14, 2015 7:48 pm
Location: Here

Re: Liquid yeast viability.

Post by McMullan » Mon Jun 08, 2020 8:27 am

Freezing is very bad for cells generally. Dry yeast cells can be stored in the freezer, although the fridge is almost as effective in terms of maximising storage time. They don't actually freeze as the water content of dry yeast is too low for ice crystals to form and burst open the cells. Yeast carnage! Wet yeast cells on the other hand need to be conditioned before being stored in the freezer.

MickJ
Tippler
Posts: 21
Joined: Fri Feb 15, 2019 7:32 am

Re: Liquid yeast viability.

Post by MickJ » Mon Sep 14, 2020 9:27 am

I have just pitched a Wyeast smack pack and don't think it's viable, out of date by a two months and was kept in the fridge at 5*c which should be OK but I just think it will be good..

Pitched Saturday night and no change in SG on Monday night...
It's a Fullers London Pride with 4120g of grain so willing to dump the lot if required..

Question is if the yeast was off will it affect the taste if I pitch S-04

Michael
Sunshine Coast
Queensland
Australia

f00b4r
Site Admin
Posts: 868
Joined: Fri Jul 11, 2014 10:54 pm
Location: Berlin

Re: Liquid yeast viability.

Post by f00b4r » Mon Sep 14, 2020 11:39 am

If the yeast is very low viability it might throw some off flavours but maybe not too noticeable. For the effort put in and the price of a dry pack you might as well try the dry yeast, the major issue is more likely the fact that any bacteria present will have had time to start multiplying.
Check the gravity and see if the yeast/bacteria have got started by now and if not then you might as well pitch the dry yeast.

Post Reply