liquid yeasts/small batches/yeast harvesting/freezing...

I'm having a blast brewing small batches (3 gallons) in my kitchen these days. The only drawback is that I am not using liquid yeasts because I don't want to spend $9 for yeast for only 3 gallons of beer.

I've thought about yeast harvesting, but I don't brew enough batches one after another or even in a brew season (Oct to April) to get many uses or even a second use out of a yeast.

But then I stumbled onto freezing yeast: http://www.schwedhelm.net/brew/yeast_harv_freeze.html

Is anyone doing this ?

I'm concerned about getting the yeast out of the primary fermentor without contaminating it. I ferment in 4 gallon plastic buckets covered with plastic wrap.

I sanitize them thoroughly and I've never had any off tastes in my brews. But to get the yeast/trub out of the pail after racking, I'd have to pour it out and I'm worried about the rim of the pail being dirty.

Am I being anal ?

Is there another way to harvest the yeast from a pail ? What about a vacuum suction setup and a hose that sucked the yeast into a sterilized jar ?

What about contaminating the yeast with the racking tube ?

How long do you think one could store frozen yeast ? The cells are dormant when frozen, right ? And it sounds like the freeze/thaw cycle is what kills them. So could yeast be frozen indefinitely, like sperm is in the dairy industry ? 1 year ? 2 years ? 4 years ?

I'd love to figure out a way to economically use liquid yeast in small batches.

Thanks

This guy has a much simpler procedure:
http://www.ipass.net/mpdixon/Homebrew/Freezing Yeast.htm

What did the first instructions use the alcohol burner for ? The first process seems to have lots of steps for possible contamination. I like the idea of using the pipette. I wonder if a sterilized syringe would work ?

I am confused about which yeast stuff in the bottom of the fermentor to use. I thought the thick slurry would be the stuff one would want. Or is that the dead yeast material ?

Yep, I am going to start doing this. Have all the stuff now. It sounds REALLY easy. My last piece of gear that I needed was a pressure cooker to use as a makeshift autoclave. Otherwise, I am good to go -- have my glycerine, autoclavable screw-top glass vials, pipette, mason jars, small cooler for the freezer, etc.

I also just acquired stuff to do starters properly (stirrer, 2L flask, etc.) since freezing small vials of yeast absolutely requires a starter.

Oh, just a note Brewman -- I think I also have everything to try a steam infusion mash now, a la Brewman's system! I just need the silicone tubing. Any chance that food grade polyethelene tubing would work as well? I know it says low pressure, but I don't consider 10 psi very much. But what about temperature problems? (Sorry to steer away on this thread.)

Hey FG ! Have you been planning to freeze yeast all along ?

Where did you get the screw top vials, pippet, etc ?

A pressure cooker as a makeshift autoclave ? What's makeshift about it ?! Its pretty much the real thing !

About the hose. I searched www.mcmastercarr.com for "polyethylene tubing" and the max temp they came up with was 200F. Some tubing is only rated for 100F. By comparison, steam at 10PSI is about 240F. Your tubing might or might not work. 10PSI doesn't seem like much, but some plastic tubing is rated for less than 20 PSI at room temp. Such tubing might fail at 10 PSI at 240F.

For comparison sake, I think the tubing I used is rated at 70 PSI at room temp and its rated to 400F. It did not seem to soften when used in my steam setup.

brewman ! said:

Hey FG ! Have you been planning to freeze yeast all along ?

Where did you get the screw top vials, pippet, etc ?

A pressure cooker as a makeshift autoclave ? What's makeshift about it ?! Its pretty much the real thing !

About the hose. I searched www.mcmastercarr.com for "polyethylene tubing" and the max temp they came up with was 200F. Some tubing is only rated for 100F. By comparison, steam at 10PSI is about 240F. Your tubing might or might not work. 10PSI doesn't seem like much, but some plastic tubing is rated for less than 20 PSI at room temp. Such tubing might fail at 10 PSI at 240F.

For comparison sake, I think the tubing I used is rated at 70 PSI at room temp and its rated to 400F. It did not seem to soften when used in my steam setup.

Click to expand...

Yes, I have been planning to freeze yeast for a couple months now since I came across one of those same articles you mentioned. Getting tired of paying $9 or $10 for liquid yeast! I have everything to do 2L starters now, and my plan was to pitch the yeast into a 2L starter before brewing, then keep 2/3 of the starter for the batch, and freeze the rest. That should yield 8 or so vials -- so about a buck a batch.

I work at the university so getting vials was no problem for me. If you like, I can get you some (but they weren't that cheap -- should pay for themselves in the long run, though). I bought my 2L Erlenmeyer flask there, too. Everything else, I scrounged up, including an old (but operational) magnetic stirrer that was being pitched.

Anyways, I want to try a hefe-weizen here soon, but realized that I either need to step mash with multiple infusions (which I am not crazy about), or get a steam infusion system working since I am mashing in my 10 gal cooler MLT. I am *that* close to finishing it -- but based on your advice, I had better order some silicone tubing. Was it expensive from McMaster Carr (especially after shipping to Canada)?

Cheers!

There have been a number of threads on this topic recently, you can search around and find them pretty easily...I take it a step father and do all of this in the lab that I work in. In fact, I have a liter or yeast growing up now in a 30*C shaker for tomorrows IPA. Need to come into work in the morning to do some stuff anyway, spin down the yeast, and bring it home.

Flyguy: that hose is $1.50 a foot if I remember correctly and looks like it will last forever. Really nice stuff. I'm thinking of using it for all my hose.

Shipping is really good/cheap with McMasterCarr. (Just watch the oversized items !) I think its $8 or some ridiculous price. I can't remember if they have a minimum order of $30 or if its Digikey, but one does.

I'm still looking for a really simple way to separate the yeast from the trub and the beer. I know about pouring the contents of the bottom of the fermentor into a jar and leaving it layer, but I'd like something simpler, like right out of the fermentor if possible. The fewer vessels and steps the better as far as I can tell.

So the layers in the bottom of he fermentor will be trub/yeast/beer, right ?

Typically, how thick will the yeast layer be ?

Could one harvest from the secondary ?

Thanks.

Thanks for the info, Brewman. I might just have to put in an order if it is that inexpensive.

There are a couple of techniques on the yeast freezing page of the wiki:

Freezing Yeast

brewman ! said:

I sanitize them thoroughly and I've never had any off tastes in my brews. But to get the yeast/trub out of the pail after racking, I'd have to pour it out and I'm worried about the rim of the pail being dirty.

Am I being anal ?

Click to expand...

You could try isopropyl alcohol around the rim. It is cheap, easy to use, and evaporates quickly.

I have been freezing/reusing frozen yeast now for a year.

I hope to get a few more years worth from my yeast
bank before having to buy more.

boo boo said:

I have been freezing/reusing frozen yeast now for a year.

I hope to get a few more years worth from my yeast
bank before having to buy more.

Click to expand...

Cool -- I really want to start doing this, too. Can you elaborate on what works for you? For example, do you sample yeast for freezing from fresh starters or do you simple harvest a yeast cake from a fermenter, how much yeast per sample do you freeze, do you use glycerin, etc., etc. It would be really great to hear what works best for people so that their success can be emulated!

I have been using the yeast from primary after I rack to secondary. I started with regular test tubes that I bought from some lab in TO which were too expensive. I now use vials like the ones WL yeast comes in.
I have been using this method http://www.schwedhelm.net/brew/yeast_harv_freeze.html by the book to freeze my yeast.

So far I have only had 1 yeast tube not work in a starter and as I let my yeast dictate when I can brew, this was no big deal.
My latest addition is WY2042. I have 4 vials saved frozen and have used the cake to make my second Pilsner Urquell clone, so I anticipate another 4 vials from this latest cake.
Sure beats paying $13 a smackpack here at my LHBS.

brewman ! said:

I'm concerned about getting the yeast out of the primary fermentor without contaminating it. I ferment in 4 gallon plastic buckets covered with plastic wrap.

Click to expand...

What about not using yeast from the fermenter at all. Buy a smack pack/vial and freeze some of the yeast in there for future batches. This should get you the purest yeast you can get.

Kai

Kaiser said:

What about not using yeast from the fermenter at all. Buy a smack pack/vial and freeze some of the yeast in there for future batches. This should get you the purest yeast you can get.
Kai

Click to expand...

I was thinking about that. I'm getting the activator packs, 125 ml, 100 billion cells. The propagator packets are 50ml, 15 to 18 billion cells. Any chance one could split an activator package into 6, one for my brew and 5 to freeze ?

100 billion / 6 would be 16 billion cells, about the same as a propagator pack.

How would one do that ? Smack it, let it start (swell), then mix it with a water/glycerin base, divide it up and store it ? Actually, my vials are 15ml, so 120/6 = 20ml, easily enough to fill a vial. Maybe I need larger vials ?

Actually I will because the yeast volume itself will be 20ml. One still needs to add glycerin or glycerin and water to it. One might need 40 ml vials. Baby food jars ? How much water/glycerin should one mix with the activator pack yeast ?

I just measured a small baby food jar and its 160 ml. Could one put 20 ml of activated yeast plus 20 ml of water/glycerin mixture in a baby food jar and freeze it and then when you want to brew, add 100 ml of glucose mixture to it and pitch right from the baby food jars ? Or would there be too much oxygen in the baby food jars when they are that empty ? What if one added more water and glycerin and then just added sugar to them when it was time to make the starter ?

I make a starter for my dry yeasts all the time, so no big inconvenience to do that for the frozen yeast when I want to use it.

I like the sound of splitting an activator pack. $9/6 = $1.50 per batch, which is fine by me. And the chance of contamination, etc will be low and there won't be any harvesting issues either.

As an aside, Wyeast says one of their packs lived 8 years !
http://www.wyeastlab.com/faqs/faqmain.htm

=================================================
How long will yeast survive?
Q. I have a smack pack of 1272 American Ale II yeastin my fridge that is four months old. How long can I leave it in the fridge before I have to send it to the local landfill?
A. Many yeast will survive for a year or more if stored properly. Activate the package and allow to swell. Make a starter culture solution of about 1.040 S.G. boiled and cooled. Add the yeast culture and incubate until high kerausen is observed.It will be ready to pitch at that point. Just a note, a brewer found a package of 1098 that was 8 years old. He activate it and it swelled within three days and made a great batch of beer. That is the oldest yeast we know about that survived and did not need any special resuitation. Nutrients are generally beneficial when propagating yeast. Try Wyeast Nutrient for the best yeast growth!
===================================================

Could anyone tell me how to freeze the yeast from an activator pack ? Specifically, how much water and glycerin should one use ?

The packs are 125 ml. Let say 5 ml gets wasted. That leaves 120 ml. I'm going to split that 8 ways, to get 15 ml of yeast slurry. How much water and glycerin should I mix with each sample before I freeze them ?

brewman ! said:

Could anyone tell me how to freeze the yeast from an activator pack ? Specifically, how much water and glycerin should one use ?

The packs are 125 ml. Let say 5 ml gets wasted. That leaves 120 ml. I'm going to split that 8 ways, to get 15 ml of yeast slurry. How much water and glycerin should I mix with each sample before I freeze them ?

Click to expand...

http://www.schwedhelm.net/brew/yeast_harv_freeze.html

"I use a 50/25/25 freezing solution (50% yeast, 25% water, 25% glycerin)."
http://www.schwedhelm.net/brew/yeast_harv_freeze.html

Does that seem reasonable ?

So, if the activator packs are 125ml and it gets split 8 ways, that would be 15ml of yeast, 7.5ml of water and 7.5ml of glycerin to a vial for a total of 30 ml.

The activator packs already have some water in them. I wonder if one could use 75% yeast, 25% glycerin ? That would be 15ml of yeast and 5ml of glycerin per vial. That would fit in a 25 ml vial.

That would be fine, you just want glycerin at 15% final concentration, the other stuff doesn't matter at all other than the amount of yeast in the solution will affect how fast a starter made from it will take off.

Ok, another quick question. If you obtain your yeast from a Wyeast pack, I guess you would want to use only the inner bag (the part you normally smack)? Or would you want to smack it normally, and divide up everything? I can see advantages and disadvantages to each approach.

FlyGuy said:

Ok, another quick question. If you obtain your yeast from a Wyeast pack, I guess you would want to use only the inner bag (the part you normally smack)? Or would you want to smack it normally, and divide up everything? I can see advantages and disadvantages to each approach.

Click to expand...

I thought that the inner pack only contains the nutrients. Since they are not necessary if you plan to freezer the yeast, you should be fine w/o smacking it. But you can also smack it, just to be sure in case the yeast is actually in the inner package. The idea is that you want to minimize handling the yeast.

Kai

I responded but for some reason, it didn't show.

I would smack it for 2 reasons
1) I don't know whether the pack is nutrients or yeast, never looked
2) let it swell for a few hours, you will have more/happier yeast to freeze down and your starters will start faster from the freezedowns.

Good discussion, guys. Thanks.

So I split a 3942 yeast yesterday. I mixed 6ml of glycerin with 16 ml of yeast and froze them. I'll report back how they worked when I use them.

brewman ! said:

I'm still looking for a really simple way to separate the yeast from the trub and the beer. I know about pouring the contents of the bottom of the fermentor into a jar and leaving it layer, but I'd like something simpler, like right out of the fermentor if possible. The fewer vessels and steps the better as far as I can tell.

So the layers in the bottom of he fermentor will be trub/yeast/beer, right ?

Typically, how thick will the yeast layer be ?

Could one harvest from the secondary ?

Thanks.

Click to expand...

Separating the yest from the trub? Hmmmmmmm.

Maybe this: http://cgi.ebay.com/NORPRO-3-Cup-Gl...surer-NIB_W0QQitemZ220075061389QQcmdZViewItem