f fried candy bars: physical.

Forget funnel cake and corn dogs, the latest fairground fare is the flied candy bar. "They're better than a regular candy bar--frying totally changes the taste," says Tina Catron, who sells the calorie-packed confection at state fairs. But how do you fry chocolate in a 177[degrees]C (350[degrees]F) vat of off without making a melted mess?

Like all compounds, chocolate's melting point (temperature at which a solid becomes a liquid) is determined by its chemical ingredients. "Most candy bars have a chocolate coating that's about 30 percent fat (oily molecule used for energy in the body)," says candy expert Mel Warnecke. Fat in chocolate melts at about 30[degrees] (86[degrees]F), or just below body temperature--perfect to melt in your mouth. But in boiling oil, a candy bar disintegrates.

The trick: Concession stands first refrigerate the bars. Then they dip them in a batter of flour, water, eggs, and sugar. The batter's proteins (chains of molecules formed by instructions from DNA) come apart in the heat. Then they quickly link up again to form a protective crispy coating before the chocolate's fat completely melts. The barrier holds any gooey chocolate inside. When the fried treat cools, the candy bar firms up again.