Cracked open a bottle of my Black IPA with a friend and to mine and his surprise there was a slight whiff of yoghurt / some kind of lactose. Very strange as there was no lactose. Aroma hops (mosaic) went in with the yeast for two weeks in a bag and then more for dry hopping at three days to go. Dry hops were commando. Tea strained out the hops on transfer to bottling bucket. Oxidization? But, don't know what that tastes like... Any ideas?