Some great info on this thread.
I was/am looking at getting a 5 litre keg because I can get it in the fridge, they are of course pretty expensive, but I was thinking that if I only have one, well if I make a 21 litre batch and stick 5 in the keg and bottle the rest, well that would probably mean my keg would be empty more than it is full.
So I was wondering, how practical is it to use a larger keg like maybe 20 litres, I think I prefer the idea of natural carbonation, and then transfer over to the 5 litre, if no oxygen gets into the larger keg, would this be a viable option?