Some call them “refreshment beers.” Others go with “lower strength beers.” Whatever the term, the beer/lemonade mix known as the shandy and similar citrus-flavored brews hold so much seasonal potential the world’s largest brewing companies have rolled out new products for, and pumped serious marketing dollars into, this emerging category. And casual dining chain Red Robin has even come up with a clever way to offer beer-based cocktails that feed off this trend.

"With governments reducing allowable blood alcohol contents for driving under the influence, lower alcohol drinks seem destined to receive more attention," Datamonitor’s Tom Vierhile tells CNBC. "2013 is shaping up as the 'summer of shandy'...while beer and lemon have been dance partners for decades, they have never had the marketing push and attention that they are currently enjoying."

Diluting beer with lemonade seems like a sacrilegious idea that would be a huge turn-off for beer purists. Or at least it did until craft brewers started churning out tasty fruit and vegetable beers by the dozens and major brewers like Budweiser, Michelob and Miller began to offer lime-flavored beers. Now the shandy looks like it could become a summertime staple restaurant operators will want to keep in stock.

Shandies have been popular in Europe for decades. Leinenkugel’s Summer Shandy is billed as the first shandy-style brew to be made in the U.S. It’s only available in the spring and summer. When sales of this item grew 80 percent in 2011, other brewers took notice, the idea being that the U.S. seemed to be virgin territory for shandy consumption.

Recently, global brewing giant AB InBev came out with Shock Top Shandy. Molson Coors now offers Rickard’s Shandy to its Canadian customers. Also, Australian brewing powerhouse Foster’s sells Foster’s Radler, “radler” being a frequently used alternative term for shandy. Heineken owns Foster’s.

Offering a slightly different flavor note, Swedish brewer Carlsberg Group has added Carlsberg Citrus, a pale lager beer with flavor notes of lime.

Craft brewers are getting on the shandy bandwagon, too. In Cleveland, much-honored Great Lakes Brewing recently offered a one-day-only shandy special to reward drivers dealing with epic traffic jams caused by movie-related road closures. A glass of Shoreway Shutdown Shandy, made of equal parts The Wright Pils and lemonade, cost $5.

Having shandies available on tap or in bottles is one way restaurants can participate in this trend. But Red Robin is using a little mixology to make its offerings stand out.

The 475-unit chain has come up with a pair of beer-based cocktails served in limited edition, reusable beer cans.

The two “Can-Crafted” drinks are:

Coors Light Can-Crafted Cocktail: Coors Light, ginger liqueur and lemonade topped with fresh squeezed lemon

Blue Moon Can-Crafted Cocktail: Blue Moon Belgian White, SVEDKA Clementine vodka, orange juice and fresh lime juice

The drinks sound good, but what’s up with the can?

"Souvenir glassware is a big part of Red Robin's heritage, and it was important to me to create something unique that could only be found at our restaurants," says Donna Ruch, Red Robin's master mixologist. "My vision for the ‘Can-Crafted Cocktails’ was to craft a craveable adult beverage in a one-of-a-kind glass that would catch the eye and act as a conversation piece for our guests. The ‘Can-Crafted Cocktails’ definitely have that wow factor." Red Robin with sell its signature beer cans for $5.

The upshot here: be aware that beer-based cocktails, beer with fruit and citrus flavors, and especially shandy-style half-beer, half-lemonade mixes can give your bar program a boost this summer. The hottest part of the season is coming up; be ready.