My gravy came out so good, I wanted to put some in a sippy cup and take it to bed with me. I made it just as I said here; my plain gravy base worked out fine. I did end up buying some from Whole Foods just as a backup, but I didn't like the taste after I got it home. Couldn't put my finger on what the offending flavor was, though. So here's the recipe for plain gravy; it is absolutely tasteless on its own, but once mixed with the concentrated pan gravy from the brined birds . . . oh, behave!
Melt 5 tablespoons unsalted butter in a large saucepan over medium-low heat. Add ⅓ cup flour and cook for 3 minutes, stirring constantly. Whisk in 3½ cups low-sodium chicken broth (I usually use Swanson's). Increase heat to medium-high and bring to a boil, stirring constantly. Reduce heat to low and simmer for 15 minutes, stirring occasionally. The gravy will be unappealingly pale and bland, but don't forget you're going to be adding that rich, dark gravy concentrate! Cool completely and store in the fridge for up to 3 days. You may need to use your new Braun hand-held blender to smooth out any lumps. (I doubled this recipe for each turkey.)