What temp does yeast die

[Spud395]

As in the topic?
I've a batch of Belgian Blond that for some reason I undercarbed (prolly had a few and fecked up the calcs)
Well I chilled one of the bottles and opened and added sugar.
This had the desired effect on carbonation but I lost a good shot of beer when the sugar dropped in.

So I'm thinking I could put the batch in the fermentation freezer, drop the temp as low as possible but keeping the yeast alive and maybe then get away with adding sugar.

The beer really benifits from a good level of carbonation and I'd like to save the batch.

[trucker5774]

If you are familiar with my turbo cider technique you will know I use low temperatures to halt the fermentation. If I let the bottles warm up again they over carb. So yes, crash it, add sugar, back to the warmth to carb and away you go!

[Kev888]

Its pretty common in commercial setups to chill to about 0c to halt fermentation and clear the beer a few points early, before casking and letting the yeast revive to complete the fermentation, rather than priming. So I'd imagine you'd be fine down to that sort of temperature.

Beyond that I'm not sure; I'm no yeast expert but i think the real issue is when you freeze wet/live yeast, as the cell walls rupture under the expansion.

Cheers
kev

[Spud395]

Cool thanks guys.
I'd say I had the last one to about 4C and it erupted when I put the sugar in.
I wonder will the extra few degrees make a difference or could it be the grains providing neutleation (sp?) sites for the co2 that is in there?
Would I be better chucking in a sugar cube I wonder?

Going to try it one bottle at a time to see what works.
It's a lovely pint with the right level of carbonation

[Kev888]

I really don't know, but if it 'is' something to do with that you could also try making a syrup - much stickier/messier but if the easier methods fail..

Cheers
kev

[Spud395]

That could be the way to go, I'll try various things untill I get something that works and report back !

[super_simian]

AFAIK they won't actually "die" until the liquid they are in freezes solid and splits their cell structure (and even then not all of them would be lost) but rather they go dormant, until a change in temp wakes them up.

[orlando]

John Palmer in How To Brew, tells a story about one of his brews that froze but still went on to be a competition winner, might have been a lager yeast though so better able to handle low temps. Tough stuff this yeast but then it has been around a lot longer than us.