Using CO2 in bottling from a bucket fermenter

[Agentgonzo]

Hold on to your lugnuts.

For a long time I used to fill 250ml 'pop' bottles from the top of a live ferment and freeze them. For months. Then remove the lid and drop them in, after mash had cooled (with ice packs). Fishing the bottle out next day. Don't recall it ever failing.

Interesting. I'll admit that I know some biology/biochemistry, but also know where the limit of my knowledge is.

I trust people (scientists, not random people down the pub!) when they say freezing causes the water inside the cell to expand (I know this from my own experience) which ruptures the cell walls and kills the yeast because I trust that scientists have confirmed this.

I also assume that if freezing was a good way of storing yeast for months between batches, then someone would have noticed it and it would become common practice. But it isn't, which leads me to believe it isn't a good way of storing yeast.

And I have not found any evidence of anyone actually trying it! (And believe things a lot more of I try it and see it with my own eyes)

But I also believe you when you say you tried it and it worked. So now I have two contradictory pieces of evidence. I wonder whether it's not black and white and that some/most of the yeast cells get killed by freezing, but some survive (via chance, or some other reason I don't know because I'm not a biochemist) and that was enough for you to have a viable sample from your frozen stock.

It's something I've thought about trying before (freezing the yeast cake and sawing if it's viable for another ferment) but not actually done it because I had low confidence it would work and I didn't want to risk a batch of beer over a £4 sachet of yeast.

I might give it a go with a small batch.

Food for thought - thank you

 

[MashBag]

I have tried a few things along the way.

Freezer temperature might be a thing.
Speed might also play a part. I am also sure as you say, there was some cellular fatalities along the way. But if you started with too many... Never got around to bunging some on a counting plate.

I have also fermented 500l from 20g of dried. Although I don't do it that way anymore, the fermentation completed aok.

Another regular recipe has 50g in 25litre.

Also sure freezing is not the best way to store yeast, but it is very easy and does work.

The only conclusion we can draw: yeast is very resilient

 

[Twostage]

I store all my yeast (brewing and baking) in the freezer. Admittedly its dry so wouldn't suffer the liquid rupture thing mentioned above. But it did ring a bell from one of the bread books that I read where they say if you make too much dough you can either put it in the fridge and use it in a couple of days (which I do regularly) or freeze it and use it in a few weeks.

Just did a quick google and Nigella Lawson (no less) says yes to freezing bread dough. Along with KingArthurBaking.com, bakingmad.com and the Kansas State University amongst others.

If you can freeze bread dough, you can freeze a yeast starter .

 

[Twostage]

I must say, @Paulus has started a brilliant thread. Anyone remember what it was about originally ?

 

[foxy]

A man's man will just brush a knobbly bit of wood through the krausen and keep the log in a jar by the door ready for the next brew.

 

[ARNWD]

I also assume that if freezing was a good way of storing yeast for months between batches, then someone would have noticed it and it would become common practice. But it isn't, which leads me to believe it isn't a good way of storing yeast.

I have started freezing yeast this year following the instructions here:-

https://suigenerisbrewing.com/?s=freezing

and here

https://www.homebrewtalk.com/threads/freezing-yeast.678455/

I use the 15ml centrifuge tubes. Two yeasts banked and the third in a starter now.

 

[ARNWD]

I should also point out that the Sui Generis Brewing blog is run by a yeast microbiologist. There are other posts on the site explaining how he runs a yeast bank for his homebrew club.

 

[MashBag]

I must say, @Paulus has started a brilliant thread. Anyone remember what it was about originally ?

I will second that.

On the subject of freezing and presumably refreezing another batch, can you refreeze food which has thawed? Is it safe to eat?

 

[Agentgonzo]

I will second that.

On the subject of freezing and presumably refreezing another batch, can you refreeze food which has thawed? Is it safe to eat?

I had this discussion with my wife (who is a microbiologist) recently.

Sometimes yes, sometimes no. There's nothing inherently unsafe about defrosting/freezing. But with things like fresh fruit, the freezing with burst cells and make them go mushy. The second round of thaw/freeze makes them more mushy. Not unsafe, but not as pleasant to eat.

For this like meat, it's not the freeze/thaw cycle that's the issue, it's the amount of time sat at 'warm' temperatures that's the issue. We use a fridge to safely store meats, and if you defrost in a fridge it's not as much of an issue. But if you defrost it on the countertop it can spend many hours at room temperature after it's defrosted when bugs can breed and produce toxins. If you freeze it, then rethaw it, then you do the cycle again. As I understood it, it's like leaving the meat at room temperature for many many hours.

 

[foxy]

Well, the weather is right at the moment for producing my sour ale, high 30's. Scrounged a 10 litre fermenter King Junior reject, after a good clean and sanitising poured in 4 litres of wort, added the Wild Brew yeast and away it went, did go up to 40C but it is within range.
I will boil and re-bottle when finished.

 

[An Ankoù]

I have always argued that dosing each bottle with standard white sugar or Demerara sugar is my preferred choice in almost all styles.

Agreed. If you dose the bottles with granulated sugar rather than solution or syrup, it will cause the beer to fizz a little on filling. This will push some of the air out of the bottle and is much more effective than trying to flush the bottles before filling. It also means that while the beer is giving up dissolved gas, it isn't going to be taking up any.
I recently tried filling my bottles to within a centimetre of the cap. Less head space, less oxygen to deal with. This had the bizarre effect of giving little or no "sshhh" when you lift the cap and you think you've got a flattie. Not at all, the beer carbonates perfectly. I do it all the time, now.
Needless to say, you should place the cap on top of the bottle immediately after filling it and crimp them all down later. The ideal is to fill all the bottles smartly since you are drawing air into the fermenter as it empties. So leave the crimping until the fermenter is empty.

 

[An Ankoù]

FYI. Read and tried minimising headspace. Made FAD... And I invert my bottles once sealed.

Sometimes I think we enjoy peeling a sparrows fart.

I found it did make a worthwhile difference. Hoppy beers stay fresh longer.
Also you save a bottle per batch. Result!

 

[Caramel Ox]

Agreed. If you dose the bottles with granulated sugar rather than solution or syrup, it will cause the beer to fizz a little on filling. This will push some of the air out of the bottle and is much more effective than trying to flush the bottles before filling. It also means that while the beer is giving up dissolved gas, it isn't going to be taking up any.
I recently tried filling my bottles to within a centimetre of the cap. Less head space, less oxygen to deal with. This had the bizarre effect of giving little or no "sshhh" when you lift the cap and you think you've got a flattie. Not at all, the beer carbonates perfectly. I do it all the time, now.
Needless to say, you should place the cap on top of the bottle immediately after filling it and crimp them all down later. The ideal is to fill all the bottles smartly since you are drawing air into the fermenter as it empties. So leave the crimping until the fermenter is empty.

With a bruloonlock you could avoid drawing air into the fermenter during the bottling. Also presumably filling cold beer into warm bottles would enable you to cap on foam. Maybe the advantage stops being measurable but the cost is minimal.

 

[Agentgonzo]

Hold on to your lugnuts.

For a long time I used to fill 250ml 'pop' bottles from the top of a live ferment and freeze them. For months. Then remove the lid and drop them in, after mash had cooled (with ice packs). Fishing the bottle out next day. Don't recall it ever failing.

Well here it goes

 

[Twostage]

Well here it goes
View attachment 96840

Exciting.

 

[Agentgonzo]

Exciting.

I just stumbled across this as well.
https://brulosophy.com/2020/02/10/i...usly-frozen-liquid-yeast-exbeeriment-results/

Looks like freezing it without glycerine won't immediately kill the yeast.

My guess is some yeast die, some survive, so as long as you have enough to start with, the beer will turn out fine. I wonder if the dead yeast cells acted as nutrients for the live ones and it all balanced itself out

Interesting that there was no mention of off flavours or head retention that is often quoted from dead yeast cells.

 

[MashBag]

Looks like freezing it without glycerine won't immediately kill the yeast.

Well fook me, who would have thunk it