To most consumers, the concept of cold coffee isn’t so hot.

But that’s something the biggest food and drink companies in the world are trying to change. PepsiCo Inc., Philip Morris Cos. and Nestle SA are all testing new cold coffee-based drinks.

Pepsi is even risking its brand name on the latest tryout, a coffee-flavored cola being rolled out in Philadelphia as Pepsi Kona.

“It’s sort of like the holy grail of the beverage business,” said industry consultant Tom Pirko of Bevmark Inc. “A lot of people have tried packaged coffee drinks, but they never catch on.”

The biggest failure so far is probably Cappio, the industry’s top seller. Philip Morris’s Kraft Foods recently pulled the canned, lightened and sweetened coffee drink after four years.

“It really wasn’t up to our standards,” said Kraft spokeswoman Patricia Browne.

Kraft is trying again, though, with Maxwell House Coffee House Iced Coffee, which is sweetened but black. It’s being tested in Richmond, Virginia.

Also in test markets are Mazagran, a carbonated coffee, and a new entry, Frappucino, both of which Pepsi makes in conjunction with coffee bar star Starbucks Corp. (Starbucks, for its part, is trying out the coffee craze in other venues, such as coffee-flavored ice creams and beer.)

Beverage companies are looking for the next iced tea. Cans and bottles of that drink went from nowhere to a significant part of the market before growth began slowing a couple of years ago.