Three days after this thread started I made 22 litres of a dark stouty portery oaty** thing which also had some cocoa. Three days ago after a 2 day cold crash I force carbed it and had a pint about 10 minutes later. With an extra ten minutes in the glass it's really coming into its own. Being closer to room temperature brought all the chocolate back to life that was there when I had a cheeky nip while kegging but got buried by the cold.
I'm going to try and get it to its third week in the keg because the last time I did a beer like this on the final pint 13 days in it was lovely.
** minch pale, porridge, chocolate malt, pale chocolate, chocolate wheat, roasted barley, caraamber, special B, target, fuggles, admiral, ekg and some hops picked by the river. I was just making it up as I went along. It doesn't taste remotely muddy or confused. 11.2% dark grains in total.