Secondary Fermentation Temperature-(I bottle)

[zoomer67]

I am still a bit confused about secondary fermentation, can anybody please help me with the following questions:

1)Definition: Just for the sake of clarification, am I correct that the purpose of secondary fermentation is mainly to make the beer clearer?

2)Temperature: by what I've read colder is better, because it clears more, but:
a)-My worry here is can it be too cold?
b)-Can I kill the yeast (which since I bottle, will not let it carbonate)?
c)-How low can I go (I have a freezer with a temp. controller!) and be safe? For example if my kit recommends 60-70 F for the yeast, should I put it at 60, or can I go down to 40 or 50 (that way I can also use my freezer to cool drinks...South Florida)?

Thanks

 

[944play]

Just for the sake of clarification, am I correct that the purpose of secondary fermentation is mainly to make the beer clearer?

...and for the yeast to (continue to) metabolize intermediate fermentation compounds, notably acetaldehyde and diacetyl. Both clearing and metabolism can take place on the yeast cake, so many brewers don't take the risk of oxidizing or contaminating their beer by racking when it's not strictly necessary.

The metabolism part works best at ferment temp or slightly higher. The clearing works better the closer to freezing you get -- this is referred to as "cold crashing." Chilling the beer for a few days before packaging will drop most of the yeast out (but there will still be plenty in suspension for bottle conditioning, even after months).

 

[zoomer67]

Thanks! You also responded my next question: Can/Should I perform secondary fermentation on any beer. By what you said, I would try to avoid it (oxidation/contamination), and just give my Primary fermentation a -cold crash-, to clarify it a bit.
I'll try this on my Nut Brown Ale...