Why does chocolate need to be tempered?

Most of the chocolate consists of cocoa solids, sugar, and milk solids that are emulsified with cocoa butter—the fat extracted from cocoa beans that, when crystallized, gives the chocolate its physical structure. When melted, these crystals are broken apart, and all those components separate into microscopic clumps. When the chocolate recrystallizes and solidifies once more, it’s nothing more than a shadow of what it once was: grainy, crumbly, discolored, and utterly disappointing. If melted chocolate is going to reset into the gorgeous, glossy dessert covering it was meant to be, it needs to be “tempered.” Tempering chocolate is the process of controlled cooling and agitation that creates teeny, tiny crystals that are evenly sized and arranged in perfect alignment. And the good news is that all this microscopic mumbo jumbo is easy to do at home, even if you’ve never worked with chocolate before.