Many recipes have you temper the chocolate—our way calls for barely melting the chocolate and then rapidly cooling it.
Dipping cookies like biscotti in chocolate adds a new spin to the confection. But to avoid a coating that turns streaky or matte instead of staying glossy, it’s important to melt the chocolate properly. That’s because when melted chocolate resolidifies, the fat can recrystallize into any one of six different forms, only one of which (called the beta crystal) hardens up shiny. The key to preserving the shiny beta crystal is keeping the temperature of the chocolate below 88 degrees. At higher temperatures, the beta crystals are destroyed, paving the way for the undesirable matte crystals to set up. Many recipes have you temper the chocolate—a painstaking process that involves repeatedly taking the chocolate’s temperature. Our way calls for barely melting the chocolate (so it doesn’t overheat) and then rapidly cooling it by adding more chopped chocolate.