Much of the beer world’s attention is on Denver this week for the Great American Beer Festival ®, a giant gathering of beer lovers and brewers of all stripes that offers a bit of a window into the emerging trends of the beer business.

The festival, which this year is hosting some 780 breweries and north of 60,000 attendees, kicked off last night in Denver’s sprawling downtown convention center with more than 3,800 beers available to sample.

While IPAs continued to dominate the playing field, some new (and old) styles are emerging, perhaps providing an early window into the trends on the horizon.

Here’s a look at what caught our eye on the show floor last night:

  • Goses, goses everywhere.  This once-forgotten German style, pronounced goze-uh, was poured by dozens of breweries, ranging from subtly sour to mouth-puckering tart. Light in body and brewed with a touch of salt, goses are sessionable, with alcohol-by-volume typically falling below 4.8 percent. We saw goses brewed with blackberry, grapefruit, coriander, blood orange and lime.

Two MillerCoors breweries, Terrapin and Saint Archer, poured their own versions of gose at a festival-week event at the Blue Moon Brewery in Denver’s RiNo district.

The re-emergence of the style and other lower-alcohol beers signals a broader shift among craft brewers to create more sessionable beer.

  • Long lines for hazy IPAs. It’s not just a trend in the northeast anymore. Festival attendees formed long lines behind breweries pouring New England-style IPAs, sometimes called NEIPAs, Northeast IPAs or double dry-hopped IPAs. The beers are essentially unfiltered or double IPAs that are aggressively hopped.

They range from slightly hazy to downright murky in appearance and tend to be lower in bitterness and heavy with fruity or floral aromas. Some compare the appearance and taste of some of these beers, which tend toward higher alcohol by volume, to orange juice.

The style originated on the East Coast at breweries such as The Alchemist, Hill Farmstead Brewery and Trillium Brewing Company, but is now one of the buzziest styles of craft beer and brewed virtually across the country.

This trend, for now, does not appear to be going away any time soon.

  • The proliferation of sours. Hundreds of variations of these beers were on offer at the 2017 event. Although barrel-aged sour beers aren’t ever likely to enter the mainstream, they dominate events like GABF that are filled with hard-core beer enthusiasts.

Today, most aspirational brewers try their hand at making a sour, ranging from barrel-aged dark saisons to kettle-soured Berlinerweisse to brettanomyces-fermented IPAs. Blue Moon, for instance, is showcasing in its Denver taproom a sour it created with fellow Denver brewer Crooked Stave.

  • A return of traditional, European-style beers. Breweries big and small are trotting  out a wave of Euro-style heritage beers such as Vienna-style lagers, Helles lagers, pilsners, Dortmunders and even Polish-style grodziskies. It’s further evidence that craft brewers are trying to crash into more occasions, mirroring what they’ve done with session IPAs.

The show continues through Saturday, highlighted with an awards ceremony that will honor the best beers of 2017 with medals.