The glass growler is an economical if imperfect vessel.

As long as you don’t have a case of the dropsies (or are overly obsessive about freshness), it’s a relatively inexpensive and easy way to cart 64 ounces of craft beer home or to a party.

While a number of breweries have shifted to amber glass to better block out light and a few now offer smaller growlers to cater to solo drinkers, the growler has not changed much over the years.

Only now are the seeds of a growler revolution being sown.

A growing number of Colorado breweries — including Great Divide, Oskar Blues and Upslope on the Front Range — are experimenting with stainless-steel growlers produced by companies betting consumers will be willing to pay more for a sturdier container that could, with innovation, eventually keep beer fresher longer.

In early October, Great Divide in Denver received a shipment of 144 stainless-steel growlers from the Portland, Ore.-based Zythos Project.

The company’s cleverly named product, The Brauler, is available at 26-plus breweries and was designed by beer writer Christian DeBenedetti and chemical engineer/entrepreneur Harvey Claussen after input from the craft-beer industry. Claussen said the vessel is twice as thick as it needs to be and designed so even a highly carbonated beer in a hot car won’t become a growler bomb.

Great Divide tap room manager Will Curtin said the brewery is sensitive to staying cost-competitive, so it is continuing to sell glass growlers alongside the stainless-steel ones that go for $35.

“Some of the appeal of glass is, I can roll by a brewery, grab one, leave it at a party and not really worry about it if it’s $5,” Curtin said. “The main drawback (of stainless steel) is the price.”

Claussen said a new carbonation tool, a “FreshCap” system, will ship early next year, giving growler beer a much longer shelf life.

“If someone can figure that out, they will have made themselves at least $1 million,” said Bryan Simpson, spokesman with New Belgium Brewing in Fort Collins. “If you can figure out a way to engineer that, the viability of growlers would grow tenfold.”

Oskar Blues in Longmont is high on its new stainless growlers because it aligns with the brewery’s pro-can gospel of portability and elimination of light damage, said spokesman Chad Melis.

Odell Brewing marketing and branding manager Amanda Johnson-King said the Fort Collins brewery has mixed feelings about stainless.

On the one hand, concerns exist “about any kind of vessel you can’t see through because you can’t tell if it’s clean,” she said. That is one reason Odell’s growlers are clear glass. Another concern is wasting beer if you can’t tell when a stainless growler is full, she said.

Other breweries stubbornly refuse to sell their draft beer to go.

“We don’t do growlers because as soon as the beer goes into the growler, the oxidation process has begun, which has immediate big effects on the flavors and aromas we worked so hard to achieve,” said Joe Osborne, marketing director for Boulder-based Avery Brewing. “If someone takes home a growler and tosses it in the fridge, the beer is not the same beer anymore within about two hours — especially IPAs and hop-forward beers.”

Osborne said Avery will watch growler developments that might prompt a change in direction.

All beer, no beefcake: The words “pinup calendar” probably conjure images of bare-chested firefighters. Or something like that.

If there are any beer bellies lurking in a new 2013 calendar spotlighting a dozen Colorado craft breweries, they are tucked safely away (or being sucked in) by fully clothed models.

The Fort Collins-based Pitchfork Pinups Calendar Company put together the project as a sequel to its similarly tasteful Farmers of Colorado calendar, which debuted in 2012 and is returning for 2013.

“We had so many people who like craft beer ask us to make a craft beer calendar, which we thought was a great idea because there are so many great breweries in our state,” said company co-founder Kelsi Nagy. “The aim is to connect people with their local food producers.”

The calendar is on sale for $14.95 plus $4.95 shipping and handling, at pitchforkpinups.com. Proceeds go to Save the Colorado River Foundation.

Golden stout: Left Hand Brewing introduced its Milk Stout about a dozen years ago after co-founder Dick Doore was inspired by Castle Milk Stout he encountered on a trip to Africa in 1998.

Back then, sweet stouts were a largely untapped market in the U.S. — save for a certain well-known Irish brand that starts with a “G.”

“While the rest of the (U.S.) craft-beer industry was pushing their IPA and competing for handles and shelf space, we faced few competitors,” said Left Hand spokeswoman Emily Armstrong.

Now, Milk Stout is Left Hand’s biggest seller. The creamy concoction was the only Colorado brew to take gold at this month’s European Beer Star awards in Nuremberg, Germany, a competition that is limited to beer categories with origins in Europe.

Eric Gorski: 303-954-1971, egorski@denverpost.com or twitter.com/egorski

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