The rules of the bar inform the prevailing ideas about what kinds of drinks may be served on the rocks. But judging by city menus, mixologists are increasingly breaking taboos — pouring Champagne, port, and beer over ice, in an effort to serve up refreshing summer drinks.

STK (26 Little West 12th St., between Washington Street and Ninth Avenue, 646-624-2444), for example, will soon offer a “Piper Piscine,” ($18) in which Piper-Heidsieck Cuvée Brut is poured over ice cubes made of the same Champagne. That way, the bubbly drink remains cool, but the flavor isn’t diluted, according to a spokesperson for the Champagne’s manufacturer, Rémy Cointreau USA, Marie Christina Batich. While high-proof spirits, such as vodka, won’t solidify in your freezer, Champagne will form ice cubes when it’s flat.

If putting an ice cube in fortified wine is a faux pas, it doesn’t bother owner and sommelier of Donna da Vine wine bar (378 Atlantic Ave., between Bond and Hoyt streets, Brooklyn, 718-643-2250), Alyssa Becker. She started doing it at home because she wanted a cooling drink, but had nothing in the cupboard except port. She test-marketed the drink by serving it to some of the wine bar’s regulars. “At first they looked at me as if I had two heads, but then they tasted it and really enjoyed it.”

Now the wine bar serves Infantato Late Vintage Port on the rocks ($7) at Sunday barbecues in the restaurant’s garden. “I like to do what I like to do,” Ms. Becker said. “I’m definitely not traditional.”

Another example of that willingness to break the on-the-rock rules is the “shandy,” also on the menu at Donna da Vine. Ms. Becker was looking for an alternative to sangria — itself an exception to the taboo against mixing ice and wine — when a staff member suggested the shandy, a combination of beer and lemonade or lemon-lime soda, popular in Europe. Ms. Becker’s version mixes Magic Hat beer with house-made lemonade and serves it over ice ($6).

At a Spanish restaurant, Suba (109 Ludlow St. at Delancey Street, 212-982-5713), beverage director Roger Kugler was inspired by both sangria and a British guest’s request for a shandy to create a brewski sangria ($11 a glass, and $33 a pitcher), a blend of one half-bottle of Brooklyn Lager with triple sec liqueur, pear purée, and fresh lemon juice, garnished with luscious juicy fresh cherries and an orange wedge, served over ice. Mr. Kugler also likes a sharp-flavored Champagne or Cava wine on the rocks.

Though many beer fanatics would scoff at the idea of diluting a true brew with any additives, there’s also a Mexican cocktail that brings together beer, lime juice and ice. “The Michelada — three parts beer, one part lime juice, with ice and a salt rim — is a very refreshing drink, popular on the beaches of Mexico,” a chef and owner of the Modern Mexican restaurant group, Richard Sandoval, said. “You can drink a lot without getting drunk.”

The “Michelada Clásica” ($7) is on the menu at Modern Mexican restaurants includaing Maya (1191 First Ave., between 64th and 65th streets, 212-585-1818), and Pampano (209 E. 49th St. at Third Avenue, 212-751-4545).

As with many mixed drinks, there’s a lot of dispute about what’s in a “true” Michelada. Variations around town include the Spicy Corona at Ditch Plains (29 Bedford St., 212-633-0202), Corona beer mixed with Tabasco sauce, lime juice, over ice with a salted rim, topped off with a shot of tequila ($9). At Hill Country (30 W. 26th St., between Broadway and Sixth Avenue, 212-255-4544), the Michaelita, named after owner Marc Glosserman’s father, incorporates Tecate beer, tequila, Worcestershire sauce, Tabasco sauce, lime juice and Hill Country’s barbecue dry rub on the rim instead of salt ($7). Hill Country also makes another “beertail,” a growing category of cocktails with a beer base. Like everything in the new barbecue joint, the Lone Star Punch ($7) is a tribute to Texas. It’s made with Tito’s Handmade Vodka from Austin, lemon juice, Lone Star beer and a splash of grenadine. Like the others, it’s served on the rocks.