I don’t agree with these 2 on “secondary”. Here is my take on it.
And if you leave a beer to long in primary it can have negative affects such as creating “soapy” or “yeasty” off flavors. These are caused by autolysis. Worse case scenario it will smell and taste like rotting flesh. This worst case scenario can take awhile but why risk it. So if you are brewing a barley wine and pitching a huge amount of yeast and planning on aging it you should likely transfer that beer to another vessel.
