If you're worried about spending all those hours on Facebook with nothing to show for it, take heart. Now that time can be used to produce something tangible: beer.

Following in the footsteps of Mountain Dew and Coca-Cola, Sam Adams on Thursday released a Facebook app that lets fans crowdsource a brew.

The app allows Facebook members to choose among various beer characteristics, including color, clarity, body, hops and malt. The attributes that get the greatest response will be used to create a "collaborative ale" that will be brewed in February. The as-yet-unnamed beer will then enjoy a limited circulation — it will only be available in select bars in Austin during South by Southwest in March and at the Sam Adams Boston Brewery. The beer will also be launched at a Guy Kawasaki's Girl + Guy party during SXSW on March 10.

Fairly tentative in the first few years of the social media age because of industry scrutiny over marketing to consumers under 21, beer marketers are using Facebook more and more. Budweiser set the tone last February with a campaign that asked fans to go on the social network to choose which commercial would run during the Super Bowl. Heineken also released a Facebook app called BeerFinder last year that paired users with a like-minded Facebook friend and let them buy a $100 BeerTender device under the pretense of buying it for the other person.

Bert Boyce, a brewer with Sam Adams, says the idea behind the latest age-gated venture is to "provide a story" behind the beer. Says Boyce: "We've done stuff in social media before, but now we're taking it to the next level."