What characteristic is associated with the use of caramel malts in a brew?

The characteristic associated with the use of caramel malts in a brew is decreased fermentability. Caramel malts are produced by steeping grains in water to convert starches into sugars, and then they are dried in a kiln. This process not only produces a variety of sugars, many of which are unfermentable by yeast, but also enhances the flavor and mouthfeel of the beer.

As a result, caramel malts impart sweetness, rich caramel, and toasty notes while limiting the amount of fermentable sugars available during fermentation. This leads to a maltier, fuller-bodied beer that may have a lower alcohol content compared to beers brewed with highly fermentable base malts.

Other options do not accurately reflect the role of caramel malts. Increased bitterness typically comes from the addition of hops, higher acidity is generally associated with certain yeast strains or souring processes, and reduced color is not characteristic of caramel malts, which often contribute deeper hues to the final beer.