Tried a cup from the remainder of the Primula cold brew I made yesterday. (It's supposed to keep for up to 14 days.) Now that I've figured out that the pour spout needs to be closed, I've managed to almost eliminate the introduction of additional bitterness.
In short, I made a cup using Equal today - not bad. Not better than iced coffee, though. Could be the coffee I'm using, of course. Problem is, I don't want to go on a coffee hunt again.