It wasn't too long ago that a cup of cold coffee wasn't worth beans. But these days iced coffee is one hot brew.
"Iced coffee has completely evolved in the past decade," said Buffy Maguire, who with her husband runs two Java Beach Cafes in San Francisco and is opening a third.
Last year, the restaurant industry served up 500 million orders of iced, frozen or what is categorized as "slushie" coffee drinks, said Bonnie Riggs, restaurant industry analyst for NPD Group, a major market research firm.
That compares with 400 million in 2006, an impressive performance considering there's been an intervening recession, which typically nips at discretionary items like specialty coffee drinks.
Iced coffee drinks on today's menus involve more than just pouring regular coffee over rocks. The beans used are premium, just as with hot coffee, and special preparations are taken to bring out the best flavor.
At Java Beach, coffee is steeped overnight or sometimes longer using a coarse grain and cold water, no heat.
"What that process does is there's virtually no acidic quality to the coffee. It just brings out this really caramel-y, chocolate element of the coffee that's really divine," she said.
Who's selling iced coffee?
Just about everyone, from big-timers like Dunkin' Donuts, Starbucks and McDonald's to most local shops. Even 7-Eleven now offers an iced coffee beverage in two flavors.
Nearly 60 percent of iced coffee is consumed at breakfast, 20 percent is treated as a snack, 13 percent of sales are for lunch and 4 percent for dinner. Consumption is heaviest in the Northeast, and the frosty java is more popular with women than men.
Iced coffee is a caloric chameleon. It can be as Spartan as black coffee on the rocks or as hedonistic as a syrup-flavored, whipped cream-infused dessert-in-a-cup.
At Java Beach, "I do give people a warning," Maguire said. "It's so smooth that you can drink quite a lot of it."