I'm reading Brew Like a Monk, which is a nice read. A little on the dry side as the author writes without ardor, but a nice read.

Still, there's a claim in this book that I want a theoretical underpinning for: adding sugar makes beer dry. The book quotes a dude named Phil Markowski, author of Farmhouse Ales:

"...there is still a fairly prevalent anti-adjunct bias among many American brewers, both amerature and professional, that makes them hold back from using enough sugar to achieve the same level of dryness that the classic Belgian examples exhibit."

and the author insinuates or asserts much the same, that sugar promotes dryness, in several places.

I'll buy that for a beer of a given gravity, the use of sugar promotes a dry beer. I'm not buying that the use of sugar makes a beer drier than a beer from the same wort without the sugar would have been. Now, I'm not buying it, but I could be convinced, given a sampling of appropriate beers or a theoretical account. But I'm thinking it's really only the first assertion that's true. (And the theoretical justification is simple: sugars are more fermentable than wort, so wort of a given gravity attenuates better if it contains sugar, and hence has less residual sugar, than an all-malt beer.)

One distinct theoretical possibility is that sugar, by increasing gravity, alters fermentation characteristics that will enhance the perceived dryness of the beer. Increasing gravity does increase ester production, so, well, theres a possibility here. But I'm not yet sold.