Yeast Question

[Dark_Ale]

When do yeast die? Sometimes you hear comments about some yeast that can tolerate higher alcohol percentages. So when you brew a big beer and the alcohol gets to a certain percentage do the yeast die, or just run out of food? I guess there not dead because you can put your new brew on top of them and get a crazy fermentation. Would you still get a crazy fermentation if you put a new brew on a yeast cake that just fermented a 1.080 brew? Why do some of the yeast settle to the bottom and some stay suspended in the brew? I guess I am just trying to understand why you would add yeast to your brew before bottling if they are suspended in the beer. When would you run into carbonation problems because of lack of yeast?

 

[Kaiser]

That is a good question Dark Ale,

If you can get a good fermentation on a yeast cake, that gave up on a 1.080 brew, then the yeast just ran out of food or the yeast went into dormancy in the higher alcohol batch. The latter may happen because the rising alcohol levels start to impede the yeasts metabolism. But I'm sure that there will be a lot that also die in the process.

I don't reuse the yeast from big-beers, so I haven't seen this yet.

Yeast may just settle to the bottom if it stops producing CO2. For some this happens earlier than for others. The settling will also be faster if the yeast forms clumps of yeast (flocculates).

Most home brewers don't add new yest to the beer before they bottle. I have done it a few times when I thought that there wouldn't be enough yeast left or when I wanted to speed up carbonation.

Kai

 

[Mudd]

When would you run into carbonation problems because of lack of yeast?

I have only run into this problem when the alcohol content was above the yeast's
tolerance. (Made some expensive, sweet pond scum water!!)
I pitch a bigger beer on to a yeastcake, up to the alcohol tolerance of the yeast.

 

[WalterSobcheck]

So is it possible, when siphoning from primary to secondary to bottling bucket, to actually leave enough yeast behind that carbonation will be inadequate? I just finished a pale ale, and I was so excited to try it since it was my first beer that came out looking like a good, solid, clear beer. When I sampled it from the bottling bucket it tasted great. Two weeks later it's flat. So disappointed. First time using carbonation drops also, but I've only heard good feedback on them. I use 12 ounce bottles with flip-top lids and solid rubber washers so I don't think it's an equipment problem.

 

[Dark_Ale]

I used those cooper drops before and they worked fine. Depending on your bottle temp I would give it longer. I had one the other day take about 5 weeks? Dont know why other than it was in a cool place. I also had a barley wine that took like a month it seemed and I used brown sugar. I would give it a bit longer before you give up on it

 

[davidkrau]

I don't think yeast dies for a long long time.I've read that divers discoverwed Spanish galleons that sank 5 or 6 hundred years ago- that they found bottles of wine that were intact-maybe in an air pocket or something. When they opened the bottles they found that the yeast was still alive and kicking. I doubt if they drank the wine. In a brew I believe the yeast eats up all the sugars and then there is nothing left to ferment and then goes into a dormant stage or hibernates until it is fed more sugar.

 

[Baron von BeeGee]

Most home brewers don't add new yest to the beer before they bottle. I have done it a few times when I thought that there wouldn't be enough yeast left or when I wanted to speed up carbonation.

I've never done that and all of my high abv (well, up to 8%) brews carbonated really well. However, I kept reading in Beer Captured how pitching additional yeast into high abv beers 3 days before bottling will greatly improve carbonation. I decided to try it with my Weizenbock and pitched some slurry Wednesday and will bottle tonight. We'll see if it helps!

 

[WalterSobcheck]

OK. So I guess what confuses me is when I hear people talk about the "yeast bed" on the bottom of a carboy. It makes me think that beer can be siphoned off the yeast bed when racking, not leaving enough in the beer to adequately carbonate when bottling time comes. I'm sure this is total rookie thinking, but this is the first time I was very particular about leaving anything solid behind when racking, and this is also the first time I had flat beer after two weeks in bottles.

 

[boo boo]

OK. So I guess what confuses me is when I hear people talk about the "yeast bed" on the bottom of a carboy. It makes me think that beer can be siphoned off the yeast bed when racking, not leaving enough in the beer to adequately carbonate when bottling time comes. I'm sure this is total rookie thinking, but this is the first time I was very particular about leaving anything solid behind when racking, and this is also the first time I had flat beer after two weeks in bottles.

Trust us, there is more than adaquate yeast left in your beer to carbonate your brew. Do you see any sediment on the bottom of your bottles? Perhaps it needs to be warmed up a tad to get the yeasts eating the rest of your primming sugar. Try swirling your bottles a little to rouse the settled yeast (if any) on the bottom and put it in a warm (75F) dark place for a week or two before trying. I have never used carb drops, but if you followed the instructions then I'm sure it will carbonate.