Wisconsin craft breweries are gearing up for another great year in 2015, extending a period of unprecedented growth in the industry. This boom is evident around the entire state, but is particularly concentrated in Madison and the surrounding region, home to four of Wisconsin's seven largest craft operations and a bumper crop of start-ups.

The craft beer scene continues to expand not only in size, but in ingenuity and scope too. Mirroring trends around the nation, Wisconsin breweries will be expanding their barrel-aging and sour programs, and get more serious about canning in 2015.

The sour trend will once again be the most notable development. While the trend of making beers with wild yeasts and bacteria grew in popularity over the course of 2014, it will assume more visibility in 2015. Seeing more sours reflects long fermentation times for these beers, so breweries that launched programs in recent months will have more to offer in coming months. New Glarus Brewing sets a standard for sours and lambic-style beers, but many more breweries are jumping into the game, including MobCraft Beer, Next Door Brewing, One Barrel Brewing and Vintage Brewing around Madison, as well as with Central Waters Brewing, Milwaukee Brewing, O'so Brewing and 3 Sheeps Brewing around the state.

More craft beer-based events are on the way too. In Madison, Ale Asylum is launching a new special release party in early summer, while One Barrel has two beer style-themed weekends in the works. Madison Craft Beer Week returns for its fifth year over May 1-10, and it will be bookended by two similar events nearby, with Milwaukee Beer Week running April 18-25 and Green Bay Craft Beer Week over May 11-17. And the storied Great Taste of the Midwest returns for a 29th year on August 8.

Around Dane County, breweries expected to open in 2015 include the Parched Eagle in Westport, Octopi Brewing in Waunakee and Funk Factory Geuzeria in Madison, and more are in the works.

Here's a look at what to look forward to in 2015 among craft breweries in Madison and around the surrounding region.

Ale Asylum of Madison

The Madison brewery is making big changes to its portfolio in 2015, and is expanding its commitment to hoppy brews. Plans are in the works to realign seasonal releases into a monthly rotation in which a hop-oriented brew is succeeded by a malt-focused beer and followed in turn by a Belgian-style release, at which point the rotation starts again. Ale Asylum will aggressively court more interest from hop heads with three new IPAs: Velveteen Habit in January, High Coup in April and Subcultcha in October. There are also plans for a special party on June 20, the Saturday before Father's Day, when it will release brewmaster Dean Coffey's take on a Russian imperial stout. The brewery is hoping that it will become an annual celebration on the craft beer calendar, akin to Surly Brewing's Darkness Day and Three Floyds Brewing's Dark Lord Day.

Capital Brewery of Middleton

This will be a big year for Capital as it moves forward on a new production brewery in Sauk City. Production supervisor Brian Destree is planning an official ground-breaking for the new facility in March, with most of the equipment in place by late summer so he can start brewing test batches in September. Full-scale production could commence by October. Also, watch for brewmaster Ashley Kinart to add a red IPA to the brewery's year-round lineup of six-packs. Capital will also release bomber bottles of a new Scotch ale in mid-February. Several more seasonals are in the works for 2015, including the rich brown ale Jobu, which is supposed to be out in April.

Funk Factory Geuzeria of Madison

Levi Funk announced in September that he plans to open his geuzeria on Madison's south side, where he will specialize in lambic-style fermentation of sour beers. The building at 1604 Gilson Street is currently being renovated before production begins, so Funk's sours are still many months away, though a handful of creations may be ready come late 2015. Meanwhile, he'll continue working with Marc Buttera at O'so Brewing in Plover. On January 23, the duo teams up to brew a traditional lambic-style beer, with the brewery opening up for their Coolship Party that celebrates the collaboration.

Great Dane Pub & Brewing of Madison, Fitchburg and Wausau

In mid-December, the Great Dane released Belgian Prairie, a tripel made with Prairie Fume from the Wollersheim Winery of Sauk City. (This beer was in my best-of 2014 six-pack). This collaboration with the winery will continue into 2015. The Great Dane will also be brewing a Russian imperial stout, some of which will be barrel-aged, while last summer's Tangerine Dream is scheduled to return on tap. Bock fans should take note that the Dane's annual Bockfest will be held on February 7.

Greenview Brewing of Madison

At least two new gluten-free beers are on the drawing board for Greenview. Brewmaster Trevor Easton says he’s working on a dark brown ale and another beer that will be barrel-aged. The brewery currently has two standard releases that are offered in 22-ounce bottles: Alt Brew Farmhouse Ale and Hollywood Nights Blonde IPA.

Grumpy Troll Restaurant and Brewery of Mount Horeb

Watch for Grumpy Troll's assertive double IPA, A&J Anniversary Ale, to return in February. This beer is a tribute to brewpub owners Annette and Jack Slocum, hence the name. Brewmaster Mark Knobel is also bringing back Norski Nut Brown, Hopsburger Pilsner and Maibock in 2015. Among the new beers at the brewpub will be a pale ale called Over and Under There. This year's Grumpy Troll Challenge home brewing competition will be held on May 16. The top beers from that event often find their way to the taps of the brewpub -- the second winner of the 2014 competition, Mike Frischmann of Mount Horeb, has his winning entry, a Belgian dark strong, on tap in late January.

House of Brews of Madison

It's all about hops for House of Brews in 2015. "I can't deny the trend and will try to have some fun with it," says owner and brewmaster Page Buchanan. He will turn out four new beers over the year, and each will highlight a specific variety of hop. Adobe Pale Ale will feature Amarillo hops, Pagoda Pale will be made with Sorachi Ace, Cathedral will offer the taste of Mosaic, and Citadel will be a high gravity pale ale with Citra hops. Buchanan is also hoping to grow his contract brewing business, and expand his taproom with a limited food menu.

Hydro Street Brewing of Columbus

Hydro Street will continue to emphasize production of its 22-ounce bomber bottles. Owners Aaron and Sandye Adams make everything happen at the brewpub with the help of a small staff, so keeping up with the demands of local beer enthusiasts can be a challenge. Releasing bombers over the last year with an emphasis on the Madison market is impressive from such a small operation. In early 2015, look for at least one addition to the bomber line with a big, dark, and full-bodied winter beer.

Karben4 Brewing of Madison

New fermenters and a bright tank will be delivered any day to Karben4 to help it keep up with the demands for Fantasy Factory IPA. Brewmaster Ryan Koga says that tank expansion will triple the brewery's potential production volume, which that ended up around 2,000 barrels in 2014. With the brewery's bottling line up-and-running, he explains this growing capacity means Block Party Amber Ale and Lady Luck Irish Red Ale are on deck. Among its seasonal brews, Silk Scorpion Black IPA is currently on tap in the tasting room, Deep Winter Coffee Stout will return in February, Idiot Farm Double IPA will come back by August, and Oaktober Ale will be out next autumn. Karben4 will also once again be involved in several collaborative brews in the works for this year’s Madison Craft Beer Week.

Lake Louie Brewing of Arena

Building on the expansion and realignment of the Lake Louie beer portfolio last spring, brewmaster Tom Porter has three new beers planned in 2015. In March, he'll release a maibock called The Twins in four-packs; its name is a reference to the astrological sign for Gemini. Come April, the brewery's Dark Shadows series will expanded with Nudge Nudge, an English-style brown ale that's named for an a Monty Python sketch. And in May, a hoppy Dortmunder lager called Blue Peter will join the Hop-A-Louie line of brews. Based on intense interest from local hopheads, Bunny Green Toe (a double IPA) will be back on shelves in January, with the lighter but still hoppy 10-81 session IPA scheduled for May.

MobCraft Beer of Madison

Everyone expects the unexpected from MobCraft, and 2015 looks to be a fun year for this creative brewery. Beers already in the works for the New Year include Dubbel Czech (a new collaborative creation with Badger State Brewing of Green Bay), Night & Day (a porter and IPA hybrid named by Draft Magazine as a notable vanilla brew), and Don Durio's Filthy Mustachio (a pale pilsner). Fans of sours should be excited about MobCraft's new Sour Stash series, which will be released in four-packs of 12-ounce bottles. The first beer in this lineup will be Sour Safari, a bottle-conditioned red ale aged in oak and fermented with Lactobacillus. MobCraft will continue using crowdsourced recipes and monthly votes to develop new beers, but it also intends to build out its portfolio of standard releases in 2015, possibly with a Juniper IPA or a Belgian-style ale. Fans should also look out for limited releases of barrel-aged brews.

New Glarus Brewing of New Glarus

After a two-year hiatus, Road Slush Stout is coming back and should be out in January. That month will also see the release of the perennial favorite Cabin Fever Honey Bock. In its Thumbprint line, brewmaster Dan Carey is bringing back his Enigma, a sour brown. The biggest news, though, is that wildly popular Scream IIPA will be joining the brewery's year-round lineup, much to the delight of hopheads around Wisconsin.

Next Door Brewing Company of Madison

Brewmaster Bryan Kreiter is jumping into sour beers, with his plans still in the development phase. Kreiter is also hinting at several collaborative beers that he is planning with other Madison businesses, to be released over the next few months. These will include take-offs on such styles as an American wheat, rye IPA, and the brewpub's Sevex stock ale. Next Door is also planning one of the more unique, if not unusual beer and food experiences of 2015, with a beer and donut pairing in the works for February.

One Barrel Brewing of Madison

Early 2015 releases from One Barrel will include Clemens Scotch Ale in mid-January and Seek and Destroy IPA in February. Both are beers that recently won local home brewning competitions. Madison's smallest brewery will also again host its celebration of barrel-aged beers over January 22-23, and its annual barley wine festival on February 19-20. Also, brewer Dan Sherman is continuing to develop his basement sour program.

Octopi Brewing of Waunakee

This new contract brewery in the works for Waunakee could be open by summer. The facility is planned for 1220 Uniek Dr. on the east end of the village. The 16,000-square-foot facility is slated to have a 50-barrel brew house with an initial production capacity of 10,000 barrels per year. Octopi will combine a contract brewing model with a selection of in-house brews.

Parched Eagle Brewpub of Westport

This brewpub on the far north side of Madison is scheduled to open in February. The Parched Eagle will be located at 5440 Willow Rd. in the town of Westport, and will encompass about 1,500 square feet of space with its own brew house, kitchen, bar and dining room. A 12-foot serving bar will be made from reclaimed local wood, and will seat about seven patrons. Once open, brewpub's capacity will be about 45 people.

Tyranena Brewing of Lake Mills

Tyranena celebrated its 15th anniversary in 2014. To mark the occasion, owner and brewmaster Rob Larson created Carnal Knowledge in the Wood, a double stout aged in rye whiskey barrels, which was my favorite barrel-aged brew of 2014. Among the beers to watch for in 2015 is the wintertime favorite, The Devil Made Me Do It, an imperial coffee oatmeal porter that's recently been re-released in the Brewers Gone Wild! series of four-packs. Among the other releases to watch out for are this year's edition of Scurvy IPA, due out in spring, and the draught-only Fargo Brothers Hefeweizen, which usually appears only for a limited time in May.

Wisconsin Brewing Company of Verona

The last year has proven to be a great time to get acquainted with the new Wisconsin Brewing Company. Its inaugural year saw the release of 13 different beers, and in 2015, brewmaster Kirby Nelson has a lengthy list of new brews he's developing. A few of those include a barley wine, doppelbock, Grissette, Bohemian pilsner, Märzen, and a black bock. Already in the works is Blister in the Sun, a beer with the hops and yeast of an IPA and the grain bill and spices of a Belgian wit -- a six-pack release is planned for summer. Nelson is also tweaking the recipes for a few of his first-year releases, including Big Sweet Life Maibock and the amber saison Bleeding Heart, which was one of my top brews of 2014.

Viking Brewpub of Stoughton

Viking opened over the summer in downtown Stoughton, and has quickly become a destination for craft beer fans from around Dane County. Since launching, its beers have been made in collaboration with House of Brews brewmaster Page Buchanan. However, the brewpub will soon start making its beer in-house. Viking owner Vik Malling expects his own 3.5 barrel system to be installed and functional by late February, and his beers to be on tap by spring. The brewpub currently offers a trio of house beers, one of which is the popular Soot in My Eye, a black IPA that should be a hit at this year's Syttende Mai festivities. On deck is a fourth brew, a strong Belgian dubbel named Chaos. Viking is also hosting a homebrewing competition on February 21, and at least one winning contestant will get to brew their recipe in the new brew house.

Vintage Brewing Company of Madison

The creations of Vintage brewmaster Scott Manning are something to look forward to every year. Toy Boat, a double IPA, will appear in January, followed in February by a dark weizenbock infused with cocoa nibs and vanilla beans. Manning is also working on a special "pink" IPA for Mother's Day that's called Bouquet. It's a white IPA that incorporates hops, citrus, hibiscus and blood orange in its recipe, and is made in collaboration with Tex Tubb's Taco Palace and the Food Fight Restaurant Group as part of a project to raise awareness and proceeds in support of breast cancer charities. Other beers to watch for from Vintage in 2015 include an IPA featuring Australian Galaxy hops, more sours and more barrel-aged brews. Manning says he has more than two dozen oak barrels. Some of these were once used for wine and others for spirits, while a few others will be inoculated for sour beer production.