A question 'bout yeast.

[kenmc]

Hi,
how come it's ok to have beer in a bottle sitting on yeast for long periods of time, yet if it sits on it for too long in a primary, it develops off tastes??
cheers
ken

 

[Turricaine]

I would think that secondary fermentation in a carboy is of heightened significance if you aim to force carbonate your beer in a keg. If you only aim to carobonate your beer by traditional methods then I would not think that a secondary is as important. At least not for normal beer, but high gravity brews might be treated differently since these have to undergo prolonged maturation. Infact for high gravity beers you might have to repitch yeast for traditional carbonation if you leave it to mature for a long time prior to carbonation.

 

[kenmc]

i don't mean to be rude, but i don't see how that even comes close to answering my question....

 

[Sasquatch]

I'm thinking two things here, ken. First, there's an awful lot of non-yeasty junk in your primary... sedimented proteins, hop bits, and what-have-you, that are not going to enhance the flavour as they decompose. Secondly, there's a great deal more "dead" yeast - yeast that has not merely gone to sleep for lack of food, but that has worked itself through all sorts of budding cycles, and is just plain old dead. In the bottle, you are likely not to have dead stuff, but merely yeast that has run out of food and is hybernating, rather than just breaking down.

That's my guess, hope it answers your question.

 

[Turricaine]

Alright, from my experience with wine making I have left batches alone for one month without developing 'off flavors'. If all you are doing is trying to develop a beer over 3 weeks prior to carbonating then I think the whole off flavors thing is a bit of a myth.

 

[wild]

Sasquatch answered it very well. It's the trub from your primary and secondary that you're trying to rack your beer off of to prevent off flavors. You'll also see this mentioned in yeast storage/cleaning.

Wild

 

[kenmc]

thanks all