By doubling down on the American IPA formula, the American brewers created new levels of hop flavor and intensity.
Generally a pale gold to a deep copper, these beers are sometimes hazy or cloudy if dry hopped or unfiltered. Like the American IPA that it's based on, the flavor profile of this beer can vary - but it is almost always fairly aggressive. Copious American hops - often citrus, piney, and floral - are balanced by a relatively large amount of alcohol and plenty of caramel malts. Hop bitterness is almost universally high, and the ABV is often 7% or above.
The term "Imperial" comes from Russian Imperial Stout, a style of strong beer originally brewed in England for the Russian Imperial Court of the late 1700s. Best served cool, 46-54 degrees, in stemmed tulip, beer snifter, or large wine glass.