We did not include American versions of these genres in our tasting, on the theory that they were not new stylistically. Nor did we include beers that used unusual ingredients or flavorings, like maple syrup, kumquats or whatever. Instead, we focused on beers that took existing styles and exaggerated them. For the most part, this means beers that are hoppy in the extreme.

Brewers have always used the resiny cone of the hop plant to add bitterness and aromas to beer. Hops and alcohol also act as a preservative, and you could make the case that India pale ale, with its higher-than-normal alcohol and hops content, was an extreme beer of the 18th century. So it makes sense that most of the extreme beers today are characterized by their ultrahoppiness. Of the 25 beers we tasted, at least 20 of them would fall into the category of exaggerated I.P.A.’s regardless of what they call themselves.

To carry their extraordinary bitterness and aromatic zest, these beers need a sturdy foundation, so they tend to have outsize malty qualities as well as high alcohol. They are not therefore session beers, brews that you can drink in multiple pints over the course of an evening. Still, the best versions, in which all the elements are well balanced, are highly appealing. Florence, in particular, was surprised at how many she found likable, and even elegant.

Our favorite was the robust 90 Minute Imperial I.P.A. from Dogfish Head, a beer that balances its exaggerated caramel and chocolate sweetness with a bracing bitterness derived from hops. If you sneer at the 90 Minute, Dogfish also occasionally issues its 120 Minute I.P.A., which, at 20 percent alcohol, may well be, as the brewery contends, “the biggest I.P.A. ever brewed.”

Our No. 2 beer, the Weyerbacher Double Simcoe I.P.A., seemed to embody the term “killer,” the extreme beer fan’s favorite compliment. Killer hops, killer fruit, overwhelming yet bearable, even enjoyable, because it is so well balanced.

The No. 3 beer, the I.P.A. Maximus from Lagunitas, was something of a lightweight in this crowd with a mere 7.5 percent alcohol, yet it was lively and energetic with a lush citrus perfume.

By contrast, the Gordon from Oskar Blues  the only beer in our tasting to come in a can  was practically mellow and subdued. Was that a good thing? We thought so, because the flavors were nonetheless distinct and complex.