So I've tried to find some information on this topic but I can't seem to find a definite answer. Does this just really come down to preference? I initially had thought to add it to the keg after I rack the beer over but then I'll have to open the lid after a closed transfer, (seems counter intuitive to me even though I can still purge the O2). My only concern about adding to the primary is that I'll be splashing the gelatin onto the wort. Just add it to the keg?
It does come down to preference and for beers I want to be crystal clear, like a pils, I've done gelatin in the primary and keg. Typically I add gelatin to the keg for no other reason than I inevitably suck up a little bit of yeast/trub during transfer and even if the beer had been fined I'd have to wait for the yeast to settle back out. Usually 2-3 pints and the beer is pretty clear.
Agreed, it's preference. I typically chill the filled keg first overnight, then add the gelatin the following day. Carbonate as usual ( I prefer the set it and forget it method).
The easy way would be to take your hydrometer jar full of brew that you just kegged plus 1 tsp of gelatin and heat to 150 (58 secs in my microwave) and add to the warm, freshly kegged brew...cool to serving temp and pour a pint of trub off 2 days in a row...common sense tells me hot will mix with warm better than hot will with cold...By the way...this works for me every time and the beer gets clearer as the keg empties...
Please disregard my previous post...it goes against conventional wisdom...and may not work better than more complex methods...