Judges Shelley Cazares, Tammy Tuck and Andrew Yu assess the competitors during Beer Madness tasting at Meridian Pint. (Deb Lindsey/For The Washington Post)

The beer universe is constantly expanding. The 2015 Great American Beer Festival’s guide for brewers lists 92 styles for its competition, as well as assorted sub-categories and catchall niches for whatever doesn’t fit in elsewhere. Only a small slice of those was represented in Beer Madness. But we still sampled an extremely diverse lot, from high-octane hop bombs to yeast-forward Belgian styles to a tart modern take on a Berliner weisse. This updated guide, listed in alphabetical order, will give you an idea of the workout our palates received.

Ale: One of the two major classifications of beer; the other is lager. Ales are made with yeast that collects at the top of the vessel after primary fermentation. They are fermented at warmer temperatures than lagers, and for shorter times. Ales often display fruity, spicy and yeasty flavors not found in lagers.

Brown ale: A darker ale that can feature chocolate, caramel or nutty flavors thanks to the use of roasted malts. American versions generally are hoppier than traditional English versions.

Double IPA or imperial IPA: The quintessential West Coast beer style, this is massively hopped, more so than a regular India pale ale, with a correspondingly heavier body and an alcohol content that can reach double digits. An American IPA, by World Beer Cup standards, measures 50 to 70 international bitterness units (IBUs; see below). A double IPA should clock in at 65 to 100 IBUs.

Dry-hopping: In this technique, more hops are added after the boil, while the beer is fermenting. That enhances the hop aroma and flavor without adding bitterness.

India pale ale (IPA): One of the most popular styles, this is an especially strong, well-hopped pale ale that was originally formulated to withstand the long sea journey to British troops in India. American IPA is a sub-style that’s stronger and more aggressively hopped than the English version, incorporating bold, resiny/citrusy Pacific Northwest hops. Some brewers use dark malts to create a style called black IPA, which has a darker color and light coffee or roast notes.

International bitterness units (IBUs): These measure the content of alpha acids, the primary bittering ingredient in hops. A mass-market American lager might measure 10 to 15 IBUs, barely above the threshold of taste. A good Pilsener will measure 20 IBUs or more, a hoppy pale ale will reach the 30s, and an India pale ale will exceed 50. Note, however, that there are many other flavor compounds in hops that don’t register on the IBU scale.

Lager: One of the two major classifications of beer; the other is ale. Lagers are made with yeast that sinks to the bottom of the vessel after primary fermentation. They are fermented at cooler temperatures than ales, and for longer periods. This gives them mellow, well-integrated flavor.

Pale ale: A hoppy, gold-to-copper-colored ale; it’s “pale” compared with a porter or stout. Some pale ales are brewed with rye to add that grain’s characteristic spicy bite.

Pilsener or Pilsner: A crisp, hoppy golden lager. The world’s major brands, such as Budweiser, Heineken and Corona, are distant approximations of this style. Examples from modern craft breweries, such as Hardywood Pils and Tröegs Sunshine Pils, are truer to the original concept.

Porter: A dark, full-bodied ale supposedly descended from a blend of beers called “three threads” that was popular in 18th-century London. A lighter, sweeter version is called a brown porter. A stronger, roastier variant is dubbed a robust porter.

Red ale: Also known as an amber ale, these copper or reddish-brown beers are known for malty, sometimes caramel-forward flavors and citrusy hops. As with pale ales and IPAs, brewers can crank up the hops and malt to create imperial or double versions of the style.

Saison: A Belgian-style farmhouse ale with fruity and spicy notes. Originally, such beers were low in alcohol and refreshing, made to quench the thirst of tired farmhands, but modern versions can be moderate to strong, with noticeable levels of hops or slight sourness.

Scotch ales: These tend to be much maltier than their English counterparts: Scotland is too cold for growing hops, and the frugal Scots weren’t going to reach deep into their pockets to import large amounts of the bitter herb. The stronger versions are also called “wee heavies.” Modern examples might contain a pinch of smoked malt to approximate the peaty flavors found in some Scotch whiskies.

Session IPA: A beer low in alcohol (generally under 5 percent by volume) with the hop-forward flavor of an India pale ale.

Sour beers: This term can refer to European beer styles such as Berliner weisse and Belgian Flanders red ale, but increasingly it’s applied to the wide-ranging category of “American wild ales.” These are beers fermented with Brettanomyces yeast and souring bacteria such as lactobacillus and pediococcus in addition to (or in place of) standard brewer’s yeast. Some modern brewers achieve tart, funky flavors by “kettle souring,” or letting the yeast go to work during the brewing process; more traditional sours rely on aging in wood to give these beers an amazing complexity encompassing tart, fruity, tannic and earthy flavors.

Stout: A dark ale, often ebony brown and opaque, with an emphasis on roasty, coffeelike and bittersweet chocolate flavors. Irish-style dry stouts are relatively light-bodied and low in alcohol, suitable for an evening of convivial drinking. Richer and stronger are foreign and imperial stouts. Milk stouts contain lactose (milk sugar) for extra body and sweetness. Imperial stouts have intense, complex flavors and higher levels of alcohol.

Witbier: Also called white beer, this is a Belgian-style wheat-based ale flavored with orange peel, coriander and sometimes other spices.