# Storing recultured yeast temps



## SnakeRider (13/1/14)

So I intend to reculture some coopers yeast as per directions on this forum.

Can I store it long term in my ferment fridge? (16-20 degrees)
or will this require a regular fridge temp? (unknown degrees)

Thanks!
SR


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## SnakeRider (13/1/14)

I will add to this.... What are the temps that will kill the yeast? frozen == dead? room temp == dead? just curious. 


Thanks again!
SR


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## warra48 (13/1/14)

16 to 20 is really too warm for storage if you want to maintain yeast health.

Keep it as cold as you can without freezing it.

How long do you want to store it?


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## Yob (13/1/14)

If you are culturing it, use it when its ready, if you are storing it, fridge temps for up to 3-4 weeks if you know your viability/vitality and have sufficient amounts.

You can freeze but is a different process and you will need to culture/step again so kinda defeats the purpose of what you want, various threads exist on all these processes. 

Sorry can't link on my old phone, but have a search for

Rinsing yeast in pictures

And

Lets freeze some yeast

Cheers


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## Ducatiboy stu (13/1/14)

Keep them in the fridge. Make up some unhppped wort to sg 1020 and pour yeast into this. 600ml pet softdrink bottles are perfect. Should last 12mnths or more. Just release the cap gently occasionaly to let the pressure out. The yeast will still slowly ferment in the fridge. Freezing is possible, but requires the use of glycerine.

Did this many times. Even sent some via post to other brewers.


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## SnakeRider (14/1/14)

Thanks guys,

Just wanted to get some coopers yeast to see what difference it makes over us-05 in exact conditions.

Will need to store it for about 2-3 weeks.

I will use my normal fridge, I was really hoping to leave all the beer stuff in the garage, hence the question. Thanks!


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## Ducatiboy stu (14/1/14)

You will need to keep it in the fridge.

Coopers yeast likes to be fermented under 18*ish. If it gets to much higher it can cause bananna/fruity flavours in your beer


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## SnakeRider (14/1/14)

So after hours of reading and youtube this morning, I have decided that this is a good approach for my first time stealing yeast:

4 cups water
1 cup light DME
bring to boil
set aside to cool
drink 3 sparkling ale tallies :chug:
pour boiled DME into a bottle
shake it like a British nanny
pour sparkling ale dregs into bottle
cover with aluminium foil
place in my ferment fridge for a couple of days.


then for my next brew, add the contents of the bottle when its time to pitch.

Any suggestions or warnings to be heeded from doing this?


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## TSMill (14/1/14)

Ducatiboy stu said:


> Keep them in the fridge. Make up some unhppped wort to sg 1020 and pour yeast into this. 600ml pet softdrink bottles are perfect. Should last 12mnths or more. Just release the cap gently occasionaly to let the pressure out. The yeast will still slowly ferment in the fridge. Freezing is possible, but requires the use of glycerine.
> 
> Did this many times. Even sent some via post to other brewers.


What is the rationale behind storing yeast in wort, I thought it was best to maintain the yeast in as dormant a state as possible, and that the prescence of alcohol was not ideal for yeast health long term? I always wash my yeast thoroughly and store under water which has been boiled and cooled (in 50mL sterile tubes which compact down to ~10-20% volume yeast). I've used yeast that has been stored for over 2 years in this manner with no discernable impact on the final product.


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## DJ_L3ThAL (14/1/14)

+1 for under water storage in the fridge after washing. I've even been lazy and not washed US05 in a reagent bottle and have warmed up to pitching temp and just pitched unwashed slurry into a brew which turned out OK (I am aware this is far from best practice).


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## Yob (14/1/14)

TSMill said:


> I've used yeast that has been stored for over 2 years in this manner with no discernable impact on the final product.


\you have stepped this up I assume? what volumes were the steps?


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## TSMill (14/1/14)

Good question, I would have gone something like 100mL, 300, 1L, 2L..... stepping up yeast is an imprecise science for me (as is recording dates on yeast vials). 

Its that I log my brews in Beersmith I was able to determine the time frame between usages. FYI it was Wyeast 1768PC (English Special Bitter), used in August 2011 and October 2013, but I've used other yeasts with 12 months plus in the fridge with no worries. 

First step may have taken a few days to get going, but smooth sailing for subsequent steps (and actual fermentation).


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## Ducatiboy stu (14/1/14)

Yeast stored in a mild wort of sg 1020 provides the yeast nutrients, but does not allow it to produce high levels of alc that will cause mutation. 

Even in the fridge the yeast is active, so it needs food to keep it going.

To truly make it dormant it needs to be almost frozen. 

Putting it in the fridge only slows it down.

When you add the yeast to your mild starter, put in the fridge as soon as you do.

It works.


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## TSMill (15/1/14)

Ducatiboy stu said:


> Yeast stored in a mild wort of sg 1020 provides the yeast nutrients, but does not allow it to produce high levels of alc that will cause mutation.
> 
> Even in the fridge the yeast is active, so it needs food to keep it going.
> 
> ...


I checked out what they have to say in the "Yeast" book:

_Storing yeast under water, as opposed to under beer, is becoming more popular. Sterile distilled water storage puts yeast in a resting state, and some reports suggest yeast can be stored in this manner for years without refrigeration......The key is to use sterile distilled water and wash the yeast slurry several times in the sterile distilled water to remove any traces of beer. _

They state a reliable shelf life of 6 months (at 3C), with a maximum of 3-5 years. In comparison, for harvested slurry it states a reliable shelf life of 2 weeks, with a maximum of 6 months. 

I realise that storage of clean yeast in a 1.020 wort is kind of between the 2, but interpolating I'd guess that sterile water is still a better long term solution than wort. I'd be keen to see some references to the benefits of wort storage though, happy to be swayed.


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## Yob (15/1/14)

interesting, I thought there was osmotic pressure from distilled water... got a page reference from the Yeast Book? I'll have to have another read of that.

:icon_cheers:


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## TSMill (15/1/14)

Yep, page 198 for a description of water immersion, and page 192 for the table of methods/shelf life. 

Disclaimer, I don't use distilled water, I use Melbourne tap water (close enough), and boil for at least 10 minutes (to dechlorinate and sterlise). Here's a crappy picture of a vial of La Sirene's Saison yeast, harvested June 2012 (sits crystal clear, but a bit of agitation moving the vial to take a pic). Oops, tubes are 30mL not 50 as stated, I'd guess the yeast has compacted down to 2-3mL or so. 

I think another member may be brewing with this one soon, so may get some more data to back up the viability of yeasts stored 12 months + under water.


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## Ducatiboy stu (15/1/14)

Well if you want to store under water then do it.

I have allways stored under mild wort and it worked well.


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## TSMill (15/1/14)

No dramas mate, not suggesting one method is right and one wrong. As I said keen to know the rationale for wort, because if it is inherently better then I will switch to doing it.


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## Ducatiboy stu (15/1/14)

Well look at it this way. You can still harvest yeast from a 12mnth old bottle of Coopers without any probs.


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## Yob (15/1/14)

but there arent fermentables in there Stu, also, not much of it's viable or vital.


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## Ducatiboy stu (15/1/14)

But there where fermentables that the yeast used up and there is enough to make a starter. You are looking at much greater volumes when storing than what you get from a single bottle.


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## DJ_L3ThAL (15/1/14)

TSMill said:


> Yep, page 198 for a description of water immersion, and page 192 for the table of methods/shelf life.
> 
> Disclaimer, I don't use distilled water, I use Melbourne tap water (close enough), and boil for at least 10 minutes (to dechlorinate and sterlise). Here's a crappy picture of a vial of La Sirene's Saison yeast, harvested June 2012 (sits crystal clear, but a bit of agitation moving the vial to take a pic). Oops, tubes are 30mL not 50 as stated, I'd guess the yeast has compacted down to 2-3mL or so.
> 
> I think another member may be brewing with this one soon, so may get some more data to back up the viability of yeasts stored 12 months + under water.



I will report the results of using this yeast slurry in about 2 weeks after I create the starter


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## Yob (15/1/14)

Ducatiboy stu said:


> But there where fermentables that the yeast used up and there is enough to make a starter.


agreed, but you are talking a priming amount of sugar, not a 1020 wort, while it's true that the yeast will remain active at a lower temp, this will favour 'some' of the yeast but not all of them, some will be dormant. It's also true that there is enough to make a starter, that doesnt mean that it's in great health to begin with.. If you are suggesting that a bottle shipped across the country and incorrectly stored at a random bottle o has 'good enough' yeast to use in a starter, I'd have to disagree. (_not that you have said that_  )

Anything I store has been let ferment right out to build up their glycogen and trehalose reserves, the reading that Ive done suggests that this is an optimal storage situation. The colder it's stored the slower they metabolise those reserves and the better the vitality.

Ive stored, and recently used, a slurry from September 13 2013, rinsed it, pitched 50ml into a 2l starter and was done in 36hrs on the kitchen table. a 4 month old slurry, un-rinsed with beer on top, that fermented a IPA from 1072 to 1012 in a week at 17'c. Not too bad for just fridge temps.


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## Ducatiboy stu (15/1/14)

All I am saying is that yeast stored in mild wort in the fridge can ( and does ) last 12mnths.

Its a method that I and others have used over the years with great success.

It was the method used when liquids first came out and we didnt have fancy things like stir plates, slants etc. 

It is simple and effective


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## Yob (15/1/14)

but we *do* have fancy things like stir plates now mate  almost any yeast storage manner, slants, frozen (correctly) shit even slurry under beer will contain yeast that can be stepped up @ 12 months.

All I am saying is that _that method_, while it _may_ work (and clearly does from your observation), isn't necessarily the best way to go _these_ days.. not saying it's wrong, just there are other ways to achieve healthy/viable/vital stored yeast.

If you are storing in 1020 wort, do you need to release the cap every so often? I assume there would be pressure build up?


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## Ducatiboy stu (15/1/14)

The reason for releasing the pressure every so often is so you dont end up with a fire extinguisher. Something that a fellow brewer found out the somewhat messy way....its more a practical thing.

Was rather funny when he told me he had yeast dripping from the ceiling and a completly empty pet bottle.


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## TSMill (15/1/14)

I went and found a 24 page thread on this topic on homebrewtalk (actually, debating storage under beer vs. water, not unfermented wort). 

If you make it to Page 21, there's a very good summary by a mircobiologist (Warthaug). 

The  main arguments for storing under beer are the presence of alcohol (and perhaps residual hop material) and the pH of beer inhibits bacterial activity, and the introduction of additional steps to the process which may introduce contamination risks. Also, obviously it is slightly easier than rinsing.

On the flip side, there are many microbiological species that can feed on fermentation products, after the yeast has become (relatively) dormant. In contrast, storage under water removes the protection of ethanol/pH, but also eliminates the food source of these potential contaminants. It is noted that ethanol/metabolic byproducts in any concentration will have a negative impact on yeast health.

In summary, the author concludes:

_In other words, with water vs. fermented wort you're dealing with 6 of one and a half dozen of the other - wort protects against some infections while supporting the growth of others; water provides no protection, but also doesn't support growth. IMO water has a slight edge in that you also rid the culture of metabolic end-products (ethanol, esters, etc) that can stress yeast. But that advantage comes with a bit of risk - any time you open your stored yeast you risk contamination from organisms in the air and in/on any equipment and materials you are using._

In my opinion, the risk of contamination is somewhat minimised if you are making starters every time (as opposed to a re-pitch) and tasting for possible infections after each step. 

Again, nothing about storage in un-fermented wort, but the risk of contaminant growth would have to be greater than that for storage under fermented beer.


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## Ducatiboy stu (15/1/14)

Here is something from the past using a different method of re-using yeast.

http://web.archive.org/web/20041210115046/http://www.grumpys.com.au/read.php3?id=26792


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## TSMill (15/1/14)

Yep, it will work, but its also going to reduce every one of my batches by 1.5-2L, plus I can easily keep 30 off vials of yeast samples in my fridge, not sure 5 would want to keep the same quantity of samples in anything much larger. This approach still has the issue that you are storing wort that is only partly fermented, and will be storing the yeast in contact with alcohol.


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## Ducatiboy stu (15/1/14)

TSMill said:


> Yep, it will work, but its also going to reduce every one of my batches by 1.5-2L,


No it wont. You add 2L then draw out 2L.


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## Scooby Tha Newbie (15/1/14)

Wow Ducatiboy is that a time machine link? Very kool mate i saved it :unsure:


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## TSMill (15/1/14)

Ah ok, I assumed that you decanted the liquid off the bulk of the yeast before adding, I wouldn't be keen for 10% or so of my ferment volume to be partially fermented wort that has sat in the fridge for months.


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## Ducatiboy stu (15/1/14)

Its more a short term method used to give good viable yeast for consecutive brews without having to muck around making starters for each brew as the 2lt you draw out is essentially a starter.

And it will sit in the fridge for months. Just pull it out, warm it up and pitch the lot. Never had any issues.

Maybe you could try it.


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## Ducatiboy stu (15/1/14)

Scooby Tha Newbie said:


> Wow Ducatiboy is that a time machine link? Very kool mate i saved it :unsure:


Lots of great info on that site in its day. We where all experimenting with a lot less than we have now, and still making fantastic beers equall to any brewed today.


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## TSMill (15/1/14)

Pretty rare that I would brew sequentially with the same yeast, let alone the same grain bill/hop schedule. 10% or so is going to impact taste for mine, so think I'm gonna give it a miss.


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## Yob (15/1/14)

For my ha' penny.. I think storing a known amount of_* rinsed, clean (dated) healthy / vital yeast*_, cannot be beaten, you can work out the pitch rate for your next brew, step it and away yo go. I will give that link a read, got it pinned but there are some pretty good methods (and even that science stuff) employed these days for good result.

for example, you know that old story, this many yeast cells for a beer with a volume of (X) and a gravity of (Y) = (Z) size starter to achieve (A Cells) or some such..

for me, it's (X) ml collected yeast, x starter size = up to 1060 (*1lt*) or above 1060.. (*2lt*) or as I like to call it... a thumb.... but If Ive rinsed it properly, Ive selected the right yeast to begin with and have stored and or split enough for starters... If Ive got my shit together I may even have some of the target wort!! Other methods (like splitting/rinsing etc) can keep that sweet spot generation (for want of a better term) going and going and going.

That said, the Fransiscan Well Brewery in Ireland has used the method that Stu talks about in his link, to keep a Wheat Yeast going (when I was there a few years ago) 128 batches... slightly more than 2lt, but same principal so I completely agree that the method works, seen it, tasted the beer... but thats the thing, it was the *same beer* and he was the first to admit that there would have been flavor drift over the time, not in a bad way, but drift all the same.

:icon_cheers:

Ed: splings


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## Ducatiboy stu (15/1/14)

The great thing is that yeast is very robust, and it takes a fair bit of abuse to kill it. 

Doesnt really matter if you spend all day with stir plates, boiled water, yeast calc charts....or just grab some slurry from your last ferment.

At the end of the day it makes beer, regardless of how anal you want to be, or how lax you want to be, excepting infections of course


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## Yob (16/1/14)

well said


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## TSMill (16/1/14)

Ducatiboy stu said:


> The great thing is that yeast is very robust, and it takes a fair bit of abuse to kill it.
> Doesnt really matter if you spend all day with stir plates, boiled water, yeast calc charts....or just grab some slurry from your last ferment.
> At the end of the day it makes beer, regardless of how anal you want to be, or how lax you want to be, excepting infections of course


All I saw was "blah blah blah, anal infections, blah....."

But you are correct that yeast is tolerant, some may even advocate not rehydrating


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## Ducatiboy stu (16/1/14)

I give up


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## Yob (16/1/14)

in answer to the OP.. something we all agree on... cold.. fridge cold is good for a direct re-pitch, assuming you have sufficient quantity in good health for up to in the order of a few (3) weeks, its better practice though to pitch an active starter if you can, second (or better than depending on POV) to that is an active starter thats been left to ferment out and settle, pour off the beer and pitch the slurry..

many different ways to go about it as this robust discussion has seen... the way that suits your practices is going to be the best way for you, if you have the time, equipment and the patience, IMO you cant go past stepping up on a stir plate (or even bottle shaking if you can be arsed) and pitching yeast thats jumping out of the flask.

as the OP will be stepping up anyway, Id try to time it so it's ready at or before it's required for the pitch and not store it in the fridge at all.

1.85 ha' pennies


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## Ducatiboy stu (16/1/14)

I have found pitching active starters the best.


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## TSMill (16/1/14)

I take a hybrid approach. If I've got 2L of starter that I don't want to pitch, I chill and decant off the beer, but then prior to pitching I get the yeast going again in a much smaller volume (say 250 mL) and pitch that at high activity.


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## Mardoo (17/1/14)

TSMill said:


> I take a hybrid approach. If I've got 2L of starter that I don't want to pitch, I chill and decant off the beer, but then prior to pitching I get the yeast going again in a much smaller volume (say 250 mL) and pitch that at high activity.



How long do you find getting it going again takes on average?


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## DJ_L3ThAL (17/1/14)

Matter of hours, if that, ive found with US05


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