Chocolate is one of the world’s most popular foods, but when a whitish coating called a bloom appears on the confection’s surface, it can make consumers think twice about eating it. The coating is made up of fats and is edible, but it changes the chocolate’s appearance and texture – and not for the better. Now scientists report in ACS Applied Materials & Interfaces (doi: 10.1021/acsami.5b02092) new information that could help chocolatiers prevent blooms from forming. Svenja K. Reinke and colleagues explain that baked goods and confectionery products, including chocolate, contain a mix of components that don’t always stay in place. Fat blooms, for instance, occur when lipids from within a chocolate product wander to the surface. They’ve long been a scourge of chocolatiers, but no one fully understood what caused them. Reinke’s team wanted to find out what factors were contributing to their formation. The researchers investigated the microscopic structural changes that occur when chocolate blooms. They found that the lipids that are responsible move through pores and cracks in the chocolate. Along the way, they soften and dissolve solid cocoa butter into a liquid form. The researchers say reducing the number of pores and the liquid cocoa butter content of chocolate could help minimise blooms.