Cold Conditioning

[Richard]

So.. I've noticed whilst drinking my first keg that cold conditioning is extremely good for clarity (2 weeks = crystal clear beer that started off opaque). A couple of things:

1. I've noticed the oxidised melanoidin flavour (faint at the start, undetectable now) fades as clarity improves. Anyone know if this is due to precipitation (clarifying) or reaction ("aging")?
2. Anyone got any tips on how to best perform the clarification? I'm basically lagering (crashing to 2C and keeping it there). Seems to work pretty well but I'm open to suggestions.

[Kyle]

I was planning to cold crash for a few days to help clarify my raspberry pale ale that I forgot to add whirlfloc and then dumped in 3 pounds of berry puree in after fermentation completed. At the moment it is a raspberry-opaque-ale.

My impression is that it only takes about 48 hours in the fridge to get good results, but we shall see.

I don't do secondary fermentation in a seperate vessel, since I find the beer is actually much better if it sits on the yeast cake for about 2-3 weeks. Is it best to wait that amount of time and then stick it in the fridge, or do so as soon as the fermentation is complete?

[Richard]

The crash pulls the yeast out of solution and the temperature thereafter causes them to go completely dormant (cold shock proteins etc), so I'm pretty sure you want to do your normal conditioning first.

A little reading answered my first question: the lagering precipitates the smaller proteins, which takes time (the 2 weeks saw a gradual transition for me from murky to crystal clear, with me er... "draining" the cloudiest pint off the bottom every couple of days). The initial cold crash precipitates the yeast and some larger proteins out of solution. Aging reactions are slowed to a crawl by the cold.