Simple Yeast Banking with Sodium Chloride

[beervoid]

Hello everyone,

I found this technique where you store 1ml of yeast in 5ml of sodium chloride 0.9% solution.

I was wondering if anyone knows if you could bank more then 1ml of yeast in a higher storage solution. if the nr's matter at all.

Cheers!

 

[isomerization]

I’ve not used this approach, but the osmolarity (concentration of salt) of the solution is what is important. I’d suspect that scaling up that ratio would work just fine (10 ml slurry into 50 mL 0.9% salt solution)

 

[RPh_Guy]

I agree

 

[NeverDie]

Hello everyone,

I found this technique where you store 1ml of yeast in 5ml of sodium chloride 0.9% solution.

Wow! Thanks for your post, without which I would not have become aware of that technique. It sounds easier than the freezing/thawing protocol.
http://wichitahomebrewers.org/resources/Yeast_Banking.pdf

 

[beervoid]

I’ve not used this approach, but the osmolarity (concentration of salt) of the solution is what is important. I’d suspect that scaling up that ratio would work just fine (10 ml slurry into 50 mL 0.9% salt solution)

Thanks for replying.

Do the ratio's matter?
Could I store for example 25ml in 50ml solution? or 5ml in 5ml solution?

 

[beervoid]

Wow! Thanks for your post, without which I would not have become aware of that technique. It sounds easier than the freezing/thawing protocol.
http://wichitahomebrewers.org/resources/Yeast_Banking.pdf

I got the info from this excellent site
https://eurekabrewing.wordpress.com/2012/09/05/yeast-banking-3-isotonic-sodium-chloride/

 

[isomerization]

Thanks for replying.

Do the ratio's matter?
Could I store for example 25ml in 50ml solution? or 5ml in 5ml solution?

I think it would depend on how “pure” your slurry is. The salt concentration is designed to match the internal osmolarity of the yeast cell. But if you have a significant amount of beer/trub present that could affect the final salt concentration. Just speculating though.

 

[RPh_Guy]

The ratio does matter. I wouldn't push it too far.

 

[isomerization]

The ratio does matter. I wouldn't push it too far.

Is your name More, Brett?

 

[RPh_Guy]

More Brettanomyces!

 

[isomerization]

More Brettanomyces!

I’d just heard a Sour Hour podcast where a guy wrote in whose name was Brett More, thought maybe it was you, haha!

 

[beervoid]

I think it would depend on how “pure” your slurry is. The salt concentration is designed to match the internal osmolarity of the yeast cell. But if you have a significant amount of beer/trub present that could affect the final salt concentration. Just speculating though.

The ratio does matter. I wouldn't push it too far.

Thank you for answering.

I'm thinking it would be a conveniant way to store my overbuild starters. Right now they are under leftover starter beer. I could decant and fill it up with sodium chloride solution.
That way my overbuild yeast would be viable longer and I wouldnt have to worry about reusing it as often.

I typically have about 50 to 100ml left and store it in 500ml duran flasks. So I would fill it up to the top with sodium chloride solution.

100ml in 500ml solution would still be ok.
What about going higher on sodium chloride? Would this be as problematic as going lower?
For example I would prefer to fill the bottle to the top to lessen oxygen space.
Then I could have 50ml of slurry vs 500ml of solution.

 

[RPh_Guy]

Let's call distilled/DI/RO water with 0.9% NaCl by the abbreviation "NS" -- that's Normal Saline.

Yes, it's OK to increase the proportion of NS relative to the yeast slurry. In fact, that makes the yeast even more comfortable.

To clarify what I said earlier: You can also decrease the proportion of NS depending on your needs, but at some point the contamination risk from increased manipulation is going to outweigh the benefit from adding NS, since the benefit will decrease. I hope this makes sense.

Where you might run into problems storing larger quantities of slurry this way is the amount of salt added to your beer, which may add appreciable levels of sodium and chloride. Just keep the extra NaCl in mind when building your water profile, if that's something you do.
I can help with the math if needed.

I’d just heard a Sour Hour podcast where a guy wrote in whose name was Brett More, thought maybe it was you, haha!

Nah, that is cool though.

 

[beervoid]

Let's call distilled/DI/RO water with 0.9% NaCl by the abbreviation "NS" -- that's Normal Saline.

Yes, it's OK to increase the proportion of NS relative to the yeast slurry. In fact, that makes the yeast even more comfortable.

To clarify what I said earlier: You can also decrease the proportion of NS depending on your needs, but at some point the contamination risk from increased manipulation is going to outweigh the benefit from adding NS, since the benefit will decrease. I hope this makes sense.

Where you might run into problems storing larger quantities of slurry this way is the amount of salt added to your beer, which may add appreciable levels of sodium and chloride. Just keep the extra NaCl in mind when building your water profile, if that's something you do.
I can help with the math if needed.


Nah, that is cool though.

Great info, I build my own water from RO and actually do add a little bit of sodium chloride to my brews... About 1.7 grams for a 5 gallon batch which gives me some Na (25ppm) and Chloride (38ppm)

I would guess after decanting the slurry not much NaCl will make it into the brew but would greatly appreciate if you could help me with the math so I can put that into my calculation spreadsheet...
Much thanks for helping out!

 

[Miraculix]

What's supposed to be the benefit of a weak salt solution instead of beer?

 

[NeverDie]

What's supposed to be the benefit of a weak salt solution instead of beer?

TL;DR The yeast lives up to an estimated 2 years if refrigerated in a very specific weak salt solution versus up to only about 3 months if refrigerated in a beer solution.

 

[soccerdad]

following

 

[jready]

Also following

 

[RPh_Guy]

I would guess after decanting the slurry not much NaCl will make it into the brew but would greatly appreciate if you could help me with the math so I can put that into my calculation spreadsheet...
Much thanks for helping out!

I. Calculate total NaCl added to the slurry.
II. Subtract what gets decanted.
III. Calculate the dilution in the beer.
IV. Divide into sodium and chloride ions.

NS is 9mg NaCl per mL

Example:
100mL slurry with 400mL NS added, and 350mL decanted, in 5 gal (~19L)...
I. 400mL * 9mg/mL = 3600mg NaCl added to slurry.
II. 3600mg * (100mL + 400mL - 350mL) / (100mL + 400mL) = 1080mg NaCl after decanting.
III. 1080mg / 19L = 57ppm NaCl added to final beer.
IV. 57ppm (23/58.5) = 22ppm Na
57ppm (35.5/58.5) = 35ppm Cl

To convert these concentrations to values as if they were added to your brewing water, we'd need to work backwards through your equipment losses and boil off.
That would ultimately help you determine how much to adjust your salts.

 

[lump42]

No, water salts shouldn't need to be adjusted. Any yeast stored for long term should be grown up in a stepped starter. Example: pull 1-2 ml from the mixed/ shaken NS bank tube and add to 100ml starter, then move up to a 1L starter after a week. The salt concentration at this point would be minimal to the a 5 batch (0.11ppm Na/ 0.17 ppm Cl). They shouldn't just be decanted and pitched, especially if sample is older. You want to know it is still alive and nothing has gone wrong with the storage first.

Larger volumes can be used to bank yeast, the concentrations and ratios should be scaled. The issue is that everytime you pull some for a starter you're risking contamination. It would be better to have 20 - 5 ml tubes than 1 - 100 ml bottle.

 

[RPh_Guy]

There's not One Right Way to do things.

If someone simply wants to extend the viability of yeast slurry, using isotonic media will undoubtedly help do that.

 

[lump42]

There's not One Right Way to do things.

If someone simply wants to extend the viability of yeast slurry, using isotonic media will undoubtedly help do that.

I guess.... but that seems to be an awful lot of extra work not to go with the researched, optimized methods. Yeast slurries can easily be kept in the fridge under beer for 6+ months if they aren't from a big hoppy beer. I've done it plenty of times no "right way", but works for what I'm doing.

 

[beervoid]

I. Calculate total NaCl added to the slurry.
II. Subtract what gets decanted.
III. Calculate the dilution in the beer.
IV. Divide into sodium and chloride ions.

NS is 9mg NaCl per mL

Example:
100mL slurry with 400mL NS added, and 350mL decanted, in 5 gal (~19L)...
I. 400mL * 9mg/mL = 3600mg NaCl added to slurry.
II. 3600mg * (100mL + 400mL - 350mL) / (100mL + 400mL) = 1080mg NaCl after decanting.
III. 1080mg / 19L = 57ppm NaCl added to final beer.
IV. 57ppm (23/58.5) = 22ppm Na
57ppm (35.5/58.5) = 35ppm Cl

To convert these concentrations to values as if they were added to your brewing water, we'd need to work backwards through your equipment losses and boil off.
That would ultimately help you determine how much to adjust your salts.

Many thanks for sharing this

 

[beervoid]

No, water salts shouldn't need to be adjusted. Any yeast stored for long term should be grown up in a stepped starter. Example: pull 1-2 ml from the mixed/ shaken NS bank tube and add to 100ml starter, then move up to a 1L starter after a week. The salt concentration at this point would be minimal to the a 5 batch (0.11ppm Na/ 0.17 ppm Cl). They shouldn't just be decanted and pitched, especially if sample is older. You want to know it is still alive and nothing has gone wrong with the storage first.

Larger volumes can be used to bank yeast, the concentrations and ratios should be scaled. The issue is that everytime you pull some for a starter you're risking contamination. It would be better to have 20 - 5 ml tubes than 1 - 100 ml bottle.

Im trying to keep it as simple as possible and would still make a starter with that slurry I had leftover and overbuild it once again to store under NS.
That way I dont have to sanitize multiple bottles and I'm thinking that there should be enough alive yeast in there to get a succesfull starter going.

 

[madscientist451]

TL;DR The yeast lives up to an estimated 2 years if refrigerated in a very specific weak salt solution versus up to only about 3 months if refrigerated in a beer solution.

I've stored yeast slurry in mason jars for much longer than 3 months and re-used it without any issues. But, the salt solution seems like a good idea. I'm just way too lazy to do all that.

 

[Miraculix]

I've stored yeast slurry in mason jars for much longer than 3 months and re-used it without any issues. But, the salt solution seems like a good idea. I'm just way too lazy to do all that.

I'll 2nd that. While the cell count reduces with time, after three months there is still plenty of living yeast left when stored under beer.

 

[SanPancho]

There's not One Right Way to do things.

When the word Irony just isnt enough.....

 

[RPh_Guy]

Speaking of salty.

Some brewing processes have well-established best practices, like aerating/oxygenating the wort when pitching yeast or using sanitizer on your cold-side brewing gear.

How to store yeast isn't one of those things where there's an obvious best way to do it.

 

[SanPancho]

...and yet you will find people all over the world do things they "shouldn't" do according to "best practices" and making perfectly good beer. Aeration, sanitizing, cleaning, pitch rates, mashing, etc. etc. etc.

its convenient to decide on your own when to be accommodating and when to be strict.

but that's just my opinion, take it with a grain of SALT.

 

[isomerization]