popping sugar is no longer just a candy in the form of Pop Rocks; it is also an ingredient with which chefs, particularly those with modernist inclinations, are experimenting to add unexpected texture and sensation to their food. The company Molecule-R, which sells popping sugar, describes the chemical process by which carbon dioxide is added to melted, cooled sugars (sucrose, lactose, and glucose; some manufacturers use corn syrup as well). As the mixture hardens, the carbon dioxide becomes trapped in the sugar, releasing with a pop when it encounters moisture, as in one’s mouth. Most pastry chefs purchase unflavored versions of popping sugar from companies like Molecule-R and WillPowder and add their own flavorings. Popping sugar’s surprising effect on unsuspecting diners makes it popular with pastry chefs who like to experiment with physical and molecular gastronomy.