I brewed an oatmeal stout and bottled it about 2 months ago. Most of the batch was drank within a few weeks of bottling. Tonight I opened the last bottle. This pour had significantly better head retention then the rest of them.
Does head retention improve with age? I know the typical factors are clean glassware, no mustache wax, etc. But all things seem equal, except it sat for a good month longer than the rest.
A bigger factor is likely nucleation sites and suspended particles in the beer. As the beer sets and conditions there are fine particulates in the beer that settle out with the yeast. The more of these super fine particles that are in suspension the more the CO2 gets knocks out as you pour it into the glass. When they are settles out to the bottom of the bottle and you separate the main beer from this as you pour. Leaving more CO2 in the beer in the glass then helps sustain the formation of head. This, IMO, gives the impression of head retention but its actually a function of the ability of the beer to continue to create head with fresh bubbles.
More time gives the the CO2 more chance to go into solution in the beer and give you better foam formation and more even carbonation.
A possibility it's that you got more carbonation with time, some times with temperatu thus your improve head formation and retention.
