For true beer nuts, a beer’s overall flavor intensity can be thought of as a pyramid of taste, with slight but notable fluctuations from level to level. Related beer-tasting terms run through the following range:
Lacking → faint → mild → slight → moderate → definite → strong → intense
As with aroma, flavor comes from malt, hops, and fermentation, all of which are balanced in a good beer. A related but more concentrated taste sensation is the aftertaste, where alcohol asserts its throat-warming ability in the strong, high-octane brews, much as it does in brandy.
Marvelous malt taste
The foretaste you encounter is the sweetness of the malt. With most industrial brews, the sweetness is delicate and perfumy and only vaguely tastes of true malt flavor, due to the lightening effect of the adjunct grain used, usually corn or rice. The fewer adjuncts used, the more the rich, caramel maltiness of the barley comes through. All-malt beers (those made without adjuncts) are appropriately referred to as having a malty character.
The more specialty grains that are used, roasted (kilned) ones in particular, the more layered or complex the beer’s flavor becomes. These specialty grains rarely add sweetness — only the flavors of the individual grain. Kilned malts create a mosaic of toasty, roasty, nutty, toffee-like, and coffee-like flavors that meld into the brew. A lot of these flavors are registered in the middle and at the back of the tongue. Some of the more highly roasted malts add a dry astringent taste that’s perceived by the tongue as being bitter, much like strong coffee or tea. Misuse of the grain by the brewer can also lead to a grainy or husky astringent flavor in the beer. Certain beers may exhibit a slight tartness that’s detectable at mid-taste.
Normally, sour flavors are considered a flaw in beer, but for several well-known Belgian beers, sourness is actually a prerequisite, as it is for a few odd ales. Lagers definitely shouldn’t be sour.
Heavenly hops taste
The primary purpose of hops is to offset the malt sweetness with a pleasant and refreshing bitterness. Hop flavors are described with pretty much the same terms used for aroma, but hop bitterness uses some new terms.
Hop flavor: Distinctive, usually tasting much like its aroma: grassy, piney, floral, citrusy, herbal, spicy, earthy, and so on; normally experienced at mid-taste. Expressed as mild, normal, definite, pronounced, or aggressive. The latter terms describe a hoppy beer.
Hop bitterness: Rather one-dimensional; experienced at the back of the tongue, as an aftertaste. Expressed as delicate, fine, coarse, or clinging.
Fabulous fermentation
The fermentation process is responsible for some of beer’s more appealing tastes, like fruit, butter, butterscotch (diacetyl), and alcohol tastes. Ales have more of the fruity and buttery flavors due to their warm fermentation temperatures; lagers shouldn’t have any of these tastes. Alcohol taste should be evident in only the strongest of beers — typically those with 9 percent or more alcohol by volume.
On the negative side of the ledger, fermentation can stimulate a long list of unpleasant flavors: the rubbery taste of autolyzed (deteriorated) yeast, cidery aldehydes, medicinal phenolics, bloody metallics, poopy enterics, and dozens of other equally unappetizing off tastes that brewers and beer drinkers alike need to be on the lookout for.