GW was the preeminent distiller of his day, until he passed and Bushrod mismanaged the distillery and it burned down. The rebuilt distillery is an awesome tour in the spring when they distill. They are 99% old school; make their own tools, coop their own barrels, wood fired (the only one left in the US), there’s only one concession to modernity, a heat plate to dry the grains, courtesy of the Fairfax County fire marshall.
You’re right about the Molasses character, it can bitter the beer pretty quickly on its own, so offsetting it with something sweeter generally how to keep that in check. Also, you want ‘unsulfated’ molasses. The distillery was/is right next to the gristmill, so almost certainly they’d have used corn as well at some point, maybe not in this recipe - I don’t recall the era in which ‘small beer’ was documented. Note: I’m making a leap with the corn, as I don’t have any documented proof but again, they made cornmeal there right next to the distillery, which is only about 2.5 miles(?) from the mansion house.
Porter has a bit of a tortured history, so American Porter and particularly in the colonial era would certainly have adjuncts in it. So far, I know of some use of pumpkins, sweet potatoes, corn & molasses. I’m sure there’s more, and in the link above he calls small beer not so small; but originally, Porter had higher gravity and initially started decreasing in gravity due to taxes. A 6-7% abv beer would not have been uncommon in that era.
If you visit Northern Virginia and the distillery is open, it is worth the visit. I can safe you some financial pain - The unaged or ‘white dog’ rye sold from the distillery tastes like fresh cut grass, and is a bit on the ‘hot’ side. The aged rye, roughly 2x the already very high cost, is very good. If you decide to buy, the money does go to a good cause; the Ladies Association keeps the estate going.
