It would be so handy if chocolate were like wax: You could melt it and cool it, and it would always have that same texture and appearance when it resolidified. Sadly, it’s not that forgiving. Good chocolate right out of the package has a nice snap and sheen. But when you melt it to use as a coating or for drizzling and leave it to resolidify, it can take on a dull, dusty appearance and soft texture. This is because the crystal structure of the cocoa butter in the chocolate has changed. Cocoa butter can solidify into any of six different crystal formations, but only one—beta crystals—sets up firm and shiny.