OG was 1.054. Not sure about the production date on the yeast pack. Aerated it with an oxygen regulator/tank with airstone.
Hear ya on the starter but have never had an issue before.
I'm not meaning to critisize your process, just offer suggestions, so please take this in the spirit in which it is intended.
You may not have had an "issue" before, but that doesn't necessarily mean you were making beer that was living up to its full potential. In this case, you underpitched.
According to the yeast cell count formula, a 5 gallon batch of ale with an O.G. of 1.054 would require 216 billion yeast cells. A single smack-pack contains around 100 billion cells on its production date, with viability dropping steadily as time passes. A 2-month old pack might only be 60% viable, for example. The production date is stamped on the smack-pack itself, so if you haven't taken out your garbage yet and are curious, you can pull it out of the trash and see how old the yeast was.
If the yeast was 2 months old and properly handled, then it contained maybe 60 billion yeast cells. If it was
improperly handled, then less still.
All that to say you may have only pitched less than 1/3rd of the yeast you should have pitched for an optimal ferment. A simple 1.5 liter starter would have boosted that cell count back up and confirmed you have a healthy, active colony of yeast ready to go to work on your wort, and spared you the nervous anxiety you're now enduring.
Aeration sounds ideal, and I'm assuming your temperatures are good, so I'm guessing it will eventually take off, and you're just experiencing an unusually long lag time because you underpitched, and the yeast are taking longer than normal to build up the necessary count. That could also mean some off-flavours, as underpitching results in stressed yeast.
Again, I'm not critisizing, just offering suggestions/possible explanations.
The more I brew, the more I understand how important yeast health and fermentation control are to the final beer. The recipes, water treatments, hopping schedules, all those are the easy (and, dare I say, more fun) parts. But the truly critical element, the part that really makes the difference between a great beer and a mediocre one, is fermentation control. Taking that extra step of making a starter, pitching the right amount of yeast, and paying close attention to fermentation temperatures, especially during those critical first few days, makes all the difference in the world.
