Guide to Making a Frozen Yeast Bank

[orangehero]

How is freezing yeast incompatible with that? You'd count the slurry before pitching no matter the origin or method of propagation.

I don't think anyone here is discounting cell counting, it's just a different topic.

Are you having major issues with yeast behavior and repeatability? There's much you can achieve simply through careful observation and consistency in techniques without expensive lab gear. Those are skills you need to learn to be a great brewer and just having a microscope is not going to help with that.

 

[butterpants]

Counting the yeast
- too many variables. Unless you have the right equipment, give up.
- you won't likely over pitch. Build up your starter (e.g., as below) to volumes you usually use and assume it works.

This guy is.

 

[jimyoung]

This guy is.

Hey butterpants, if you feel that my framing would discourage people from looking into and learning about the proper way to count, given that the large number of variables involved in freezing makes it hard to calculate off-hand, please suggest an amendment and I'll add it. E.g., if you have a recommended thread to get people started, etc.




ps - every time I read your alias I think of the strong diacetyl taste on a young lager, which I somehow quite like

 

[butterpants]

Most of me is deliciously buttery.

There are quite a few guides already written on cell counting.... videos too. I don't have time nor the desire to recreate them... most are done quite well. I don't think the issue is variables, it's lack of practice by the counter.

Cell counting via hemocytometer is a very well vetted technique. The math associated with it is simple and solid. You can buy a cheap AmScope for counting.

 

[GQT]

Gents, question to those who know for a fact: Would paraffin oil do for yeast immersion for freezing _and_ not for freezing, just for keeping in fridge?
The books only state some "mineral oil" but paraffin oil is the only one easily available to me.

 

[orangehero]

Generally speaking mineral oil = paraffin oil. We are using glycerin for freezing protection, though.

 

[GQT]

Generally speaking mineral oil = paraffin oil. We are using glycerin for freezing protection, though.

Thanks, I'll search for glycerin. Shouldn't be too hard to locate I believe.
BTW, I know the source of your avatar

 

[butterpants]

ebay has lots of sellers

 

[GQT]

ebay has lots of sellers

Yeah, where am I and where is ebay.
We eat from different plates and buy from different sources.
But I've got glycerin already. It was really easy to find, thanks everyone for directing me in a right way.

 

[butterpants]

where is ebay.

You're joking right?

 

[GQT]

You're joking right?

I never asked, WHAT ebay was.
I said, WHERE.
Given the fact that I am in mainland China (shown next to my nickname) this isn't exactly a joke.
Ebay is a no go - it's no problem ordering there but shipment will cost stupid money and why bother if 90% of all sold on ebay is made somewhere a couple of blocks away.
So I shop at taobao.com, a (should be the) internet trade portal of China.

 

[butterpants]

I only use the mobile app.... I can't see details like user location, avatars, sigs, etc without digging for them. My bad.

Yes, China does complicate things. Could be worse.... you could be in North Korea....

 

[GQT]

Could be worse.... you could be in North Korea....

Huhh, in my nearly 20 years in China there were times I loved her, liked her, did both, or did neither. But I'd never say it's as bad as to be remotely compared to NK. Hey, just from a brewer's point, what about a 13-gallon stainless pot (2.5 mm thick no crap monster) costing 23 bucks delivered to my door?
And take it from me, all this internet censorship and alike, when you think of 1.5 bln guys (talking people, not yeast cells!) that are enjoying some 30-years lasting peace period for the first time in like 500 years... could be worse, oh yes it could.

 

[Hanso]

POTDA
Just seeing this now... GQT gets my vote for post of three days ago.

 

[pricelessbrewing]

Alright looking to add a frozen bank as redudency for long term storage of mother cultures in addition to the short term storage of liquid media via yeast starter harvesting.

What storage containers are everyone using? I do small batches, and am in an apartment, so probably looking at the 1.5-10 ml range. Needs to be a leak proof seal, autoclavable.

 

[butterpants]

Get gamma irritated screw top pcr reaction tubes. Seals better than flip top and pre-steralized.

 

[Hoofer]

Sticky this!

 

[pricelessbrewing]

Just set up 5 frozen tubes of 510, and 570. Mixed up two nights ago, and am ready to freeze them.

Is the current mindset to freeze quickly, freeze slowly, or don't worry about it?

 

[butterpants]

I would chill them down slow, let the yeast build up Trehalose stores. Helps them weather the proverbal coming storm.

http://www.ncbi.nlm.nih.gov/pubmed/2256682

 

[pricelessbrewing]

I would chill them down slow, let the yeast build up Trehalose stores. Helps them weather the proverbal coming storm.

http://www.ncbi.nlm.nih.gov/pubmed/2256682

Cool, I placed them in a thermos in the freezer. Should occur slowly.

 

[Kwitty]

Don't know if it's too late but here use freezable Breast Milk Bags. My wife Breast feeds our babies. The bags are for storage and freezing of breast milk. They need to be steril from the factory. They have a double Ziploc and we've never had one leak. They are a bit big but you can store whatever amount you want. I squeeze out most of the air and freeze. No pressure cookers or sterilizing and I've never had a bad batch. Just use a new bag each time! A box of 100 is about $15-$20 but for me that box will last a long time.

 

[butterpants]

.... his beer always tastes firm and supple

 

[pricelessbrewing]

I'm sure that works quite nicely for pitchable volumes. I prefer my frozen banks to be on the small size though so I can have a bunch of strains and not take up the entire freezer.

 

[Kwitty]

The bags are 6oz but I only put about 40ml at most in a pouch. I squeeze the air out so they dont take up space. What I do is freeze them flat and file them in a box / cooler like files because they're so thin. I have 5 yeast varieties in my freezer now and about 5-7 pouches each. That's about 30 pouches in a 8x6x6 cooler in my chest freezer. I write right on them what they are so no labels needed. I guess I could do pitchable volumes if I washed my yeast and used that, but I make starters and split that into smaller amounts. To each their own. I'm just telling what I do and works for me. If my idea works for someone else, great! If not, that's fine too.

 

[hawgwild81]

The bags are 6oz but I only put about 40ml at most in a pouch. I squeeze the air out so they dont take up space. What I do is freeze them flat and file them in a box / cooler like files because they're so thin. I have 5 yeast varieties in my freezer now and about 5-7 pouches each. That's about 30 pouches in a 8x6x6 cooler in my chest freezer. I write right on them what they are so no labels needed. I guess I could do pitchable volumes if I washed my yeast and used that, but I make starters and split that into smaller amounts. To each their own. I'm just telling what I do and works for me. If my idea works for someone else, great! If not, that's fine too.

This sounds great! My wife is breast feeding too, so I have a ton of these pouches. Your just freezing the yeast? Your not using any glycerine or anything to prevent cell damage to the yeast when freezing?

 

[Kwitty]

No! I'm still using the glycerin and doing all the same steps to freeze the yeast. I'm just not using reusable vials and sterilizing them each time. I am using the breast milk bags instead of the vials. You still need to prep the yeast, it's just a different container.

 

[orangehero]

If you don't have a pressure canner or cooker then how are you sterilizing the glycerin?

 

[Kwitty]

I dilute the glycerin with water to a 20% mixture and boil it in the microwave for 5 minutes. It may raise the percentage a bit but it's OK. I mix the glycerin mixture 50/50 with yeast slurry. That cuts the glycerin in half so we now have approximately 10% glycerin. Probably slightly higher with the water that evaporated in the boil.

 

[zam216]

Here is my go at frozen yeast banking it seems to have been a success. Check it out if your interested in seeing how its done.

[ame]https://www.youtube.com/watch?v=iDIwwnFFHLQ[/ame]

 

[butterpants]

Jason I liked the video. Very off the cuff with decent layman's explanations of why you're doing what you're doing. My 2 cents....

1) Might look into adding a small amount of citric acid to the glycerine/DI water mixture. Helps with oxidation. Isotonic saline might be better than DI water too.

2) Keep an eye on those tube caps. The PP ones (not resin) can sometimes warp post autoclave. Wrap the tops in parafilm or electrical tape before freezing.

3) You go through all that trouble to sterilize then open all the tubes at once and expose them to the air? Don't do this... one at a time. Also light a candle/alcohol lamp and work in close proximity to it. The updraft will keep falling particulate (dust), which carry bacteria and wild yeast.

4) That Cinnamon Toast Crunch box in the background was calling my name the whole time....

Thanks for the vid