As a diverse but distinctive style, IPA bestrides the craft beer world like a colossus. As author Dick Cantwell says, "We are living in the heyday of IPA." While hops remain front and center in the myriad examples of IPA available to beer drinkers today, the style is also now subject to vast experimentation and "dressing-up," producing fruity, herbal, black, Belgian-y, and juicy versions of this perennial favorite. Brewers are pushing the boundaries...