Yeast freezing sample size

[reese9885]

Hey everyone, so I decided to get into yeast ranching going about the freezing with glycerin method. Mainly to be able to have a steady supply of yeast on hand and also to save a buck... anyways my friend has tons of glass boston round bottles on hand he said I could have... I can either get 1/2 oz, 1 oz, or 2oz bottles.... which would be better to use? Know the smaller the bottle the faster itll freeze causing least amount of damage to the yeast...or should I be worrying about the amount of yeast slurry which the 2 oz would have the most...and at the same time 2 oz would take more glycerin which would result me spending more money on that. (Which still might save me money in the long run)...so just wondering what everyone else is using size wise and which be better for me.

He also has them in different colors clear, cobalt , and amber not sure if this matters or not but opnions welcomed.

 

[Beernik]

I can't help but I'm very interested in the answer.

 

[trentm]

Hey everyone, so I decided to get into yeast ranching going about the freezing with glycerin method. Mainly to be able to have a steady supply of yeast on hand and also to save a buck... anyways my friend has tons of glass boston round bottles on hand he said I could have... I can either get 1/2 oz, 1 oz, or 2oz bottles.... which would be better to use? Know the smaller the bottle the faster itll freeze causing least amount of damage to the yeast...or should I be worrying about the amount of yeast slurry which the 2 oz would have the most...and at the same time 2 oz would take more glycerin which would result me spending more money on that. (Which still might save me money in the long run)...so just wondering what everyone else is using size wise and which be better for me.

He also has them in different colors clear, cobalt , and amber not sure if this matters or not but opnions welcomed.

I store yeast on slants so I don't have experience with freezing yeast at home. However, I do have professional experience in storing and using bacteria from cryostorage. In the lab, we use 1.5ml cryogenic vials. When it is time grow up a culture we take only a tiny amount (pinhead sized) and streak onto a solid media plate to isolate pure colonies. From there the colony (ies) are either spread as a lawn onto another solid media plate or suspended into 10ml of liquid media. That said, smaller is better for the sake of space and using the described method you would never use up a culture. Larger may be better if you plan on using a large amount to directly inoculate a starter. The answer to your question depends on how much you will use to grow up a starter and how many times you would use the stored culture. If you plan to reuse from the same vial, be sure you have a working culture and a permanent culture. The latter would not get opened unless you loose the working culture or you feel the working culture is been abused.

 

[reese9885]

Well my plan is to when I make my starter for my wort to make a secondary starter and add a little bit a yeast to it and toss the rest in the primary. .. then use the secondary to build up yeast to add to 10 bottles to freeze.. when I go to use 1 of the samples make a starter out of it by tossing the whole sample in (not bothering with reusing same sample) then start another secondary for 5 samples of 2nd generation yeast and... then break down 2nd generation to 3rd in 2 samples and after everything said and done think my math came out to 160 samples of 1st 2nd and 3rd generations.

 

[reese9885]

Which might take up alot of room soo guess thats a bonus to the 1/2 oz samples less room they take to store. Which thinking about it might just do 20 1st generation samples and say screw the rest..undecided

 

[tally350z]

One question I have for you is you are saying that you are going to making two starters, one to use in a brew, and the other to make more frozen yeast samples correct? Than you will use one of those frozen yeast samples and make two starters out of that, one to use and the other to use for more freezing?
How often will you be brewing using these frozen yeast cultures? Normally the frozen yeast cultures are for long term storage,up to 5 years and beyond. It seems like a lot of work to just freeze the yeast and than reuse the frozen yeast within a few weeks/months. I'm not trying to say that what you are doing is wrong it just seems like the amount of work put in for such a quick turn around is overkill..

Also, this method is for one yeast strain? So by your calculations if you wanted two yeast strains the amount of samples will double to 320?

 

[reese9885]

Thats exactly and was just saying that could be the result, mostly likely would never go that high in amount of samples wise... overkill is what I do best lol

 

[tally350z]

that tends to happen with this hobby..

 

[trentm]

Well my plan is to when I make my starter for my wort to make a secondary starter and add a little bit a yeast to it and toss the rest in the primary. .. then use the secondary to build up yeast to add to 10 bottles to freeze.. when I go to use 1 of the samples make a starter out of it by tossing the whole sample in (not bothering with reusing same sample) then start another secondary for the sample and for 5 samples of 2nd generation yeast and... then break down 2nd generation to 3rd in 2 samples and after everything said and done think my math came out to 160 samples of 1st 2nd and 3rd generations.

That seems like a working plan. You would need to have an idea of how many cells in your sample to pitch to the desired starter size. There are lot of cells in a concentrated slurry. When I am stepping up a starter from a slant I like to pitch 35 million cells per ml of 10 degree Plato (1.04) wort. So for a 1L starter it would be nice pitch 35 billion cells. I have the luxury of counting cells but I think there are some online yeast calculators that estimate the number of cells in a slurry. See if you can figure the volume of slurry you would need for each sample then multiply by 2 (because you want half glycerol half yeast...right?) and that would be the container size you need. You would want to figure a little head space for expansion.

Disclaimer: The 35 million cells per ml of 10 degree Plato wort is a number I came up with and is about 4.5 times the amount for pitching when brewing beer. On the other hand it is about one third the amount in a commercial yeast pack. I think it is a good number and commonly get counts of 250 - 300 billion cells per liter when growing up from slants.

Disclaimer to the disclaimer: You have to have a very well aerated starter to get those counts.

 

[Weezy]

I use 50ml plastic bottles, off eBay cheap, and save ~25 ml loose (5-10 ml dense) slurry from the starter in each. Top up to 40 ml line with glycerin & freeze. I'll make 2-3 per starter batch, assuming i'm saving some. Then freeze each and build each back up into a new pitch when I need it in the future. Haven't had a dead one yet and I have rejuvenated 16 month old yeast.

I'd go with the 2oz, since they're free. You won't be saving that much so you'll have to step it up a few times, but they should work just fine. Bottle color doesn't matter.

(the pic was for a previous discussion, showing the container and the creamer. I use the creamer to pour into the little containers. No funnel required.)

 

[trentm]

One question I have for you is you are saying that you are going to making two starters, one to use in a brew, and the other to make more frozen yeast samples correct? Than you will use one of those frozen yeast samples and make two starters out of that, one to use and the other to use for more freezing?
How often will you be brewing using these frozen yeast cultures? Normally the frozen yeast cultures are for long term storage,up to 5 years and beyond. It seems like a lot of work to just freeze the yeast and than reuse the frozen yeast within a few weeks/months. I'm not trying to say that what you are doing is wrong it just seems like the amount of work put in for such a quick turn around is overkill..

For me, it's all about yeast health. In storage, (>32F) yeast use glycogen (and other stored carbohydrates) for survival. When pitched, yeast need that store of carbohydrates while developing strong and permeable cell membranes prior to the use of wort sugars during the lag phase. The graph below illustrates the fate of intracellular glycogen at 2 different temperatures, 4 degrees C (39F) and 15 C (59F) over 6 days. Twenty percent glycogen is adequate for pitching so yeast stored for 6 days at 39F is fine for pitching but after that the glycogen levels may need to be replenished. Freezing temperatures halt this process and that's why cryopreservation works so well. Sure you can replenish the carbohydrate levels by stepping the yeast through starters but that's also a lot of trouble. Healthy yeast make great beer.

 

[tally350z]

Absolutely that storing frozen yeast provides an added benefit in yeast health, the only thing I was leaning towards was that for what the OP wanted according to his post, was a quick turnaround. Still hasn't specified how often he will be brewing with the yeast. Freezing yeast may no be his best option, when dealing with yeast. The cost benefit doesn't justify what he wants. When I make my yeast slants, I can store multiple strains in smaller sample sizes and am able to have a quick turnaround. But to each his own so it sounds like he is on the right track with what he wants..

 

[trentm]

I certainly agree and for me the slant method is the best way to get the healthiest most viable yeast cultures. However it may have a higher learning curve compared to freezing (although I have never tried it). You may have picked up that I am bordering obsessive/compulsive when it comes to yeast. Some get into yeast storage to save money but I have more money in my yeast lab than my brewery. For me it's all about healthy yeast.

 

[reese9885]

Well I brew whenever I can that being said sometimes a fast turn around will happen and ill use my yeast up quick but sometimes ill go month sometimes 2 if im really busy... so need a option that can do both, whenever I need it so this seemed more suiting to my needs

 

[tally350z]

Make sure to post pics of your process..