It's not necessary at all. Some like to do it, though, to precipitate out as much stuff as they can. Chilling it down for 24-48 hours (or longer) causes more yeast to fall out, may reduce chill haze, etc, so you have clearer beer to rack to the keg. Some even use finings like gelatin at this time, to have the clearest beer possible.
I do it for the reasons listed above, but also because I don't have a scale that can read a full 5-gallon keg. Chilling the beer lets me see how full the keg is getting by the condensation line.
-keith
Yeah, other than wheat beers, I crash cool for a couple of days before racking to the keg. As an added bonus, the beer is cold so you can start force carbing right away.
Yeah, other than wheat beers, I crash cool for a couple of days before racking to the keg. As an added bonus, the beer is cold so you can start force carbing right away.
You can force carb right of that bat even if it's a little warm, just put in in your kegerator to cool. It carbs better being chilled, but you can start as soon as you keg. Either way hit it with 30 PSI or so to ensure you have a sealed keg.