I always get impatient for my bottles to carbonate and inevitably pop one open before it's ready. It's interesting to see how the flavor changes as the carbonation changes--and with this beer it was especially apparent--but I frequently regret it. After only two weeks in the bottle it was still almost completely flat and tasted like root beer. I have no idea where that flavor came from (yeast maybe?), but it was very prominent.
As the beer continued to carbonate, the root beer flavor faded. However, as I mentioned in the bottling notes, I miscalculated the priming sugar so this took awhile. I intended to make it pretty carbonated, so the smaller dose of priming sugar it ended up being okay. English beer--like oatmeal stout--tends to have lower carbonation levels anyway.
Besides changing the mouthfeel, carbonation also liberates aromas from the beer, carrying them to your nose and mouth. Once this stout fully carbonated, one such aroma was a faint smokiness that was hidden before. It's a pleasant woody smokiness--not rubbery like the IPA last summer--which works well in a dark beer like this, but not what I intended. Since I had no smoked malt in the recipe, it is probably coming from the toasted oats that I didn't let sit as recommended.
Overall, I'm happy with how this beer turned out. There are no major off flavors that detract from the beer, just some things that didn't go as planned. It's a little thinner and drier than what you would expect from an oatmeal stout, but still an enjoyable beer in its own way.