"Fat bloom happens when fat migrates to the surface of chocolate as a result of storing it at high temperatures or exposing it to extreme fluctuations in temperature," lead researcher Nicki Engeseth, a member of the Institute of Food Technologists, says in a statement.
Engeseth and colleagues investigated optimal chocolate storage and they recommend not storing Valentine's chocolate or hiding Easter chocolate from the children in an automobile. An automobile is also a bad place for chocolate in the summer.
To help keep chocolate looking and tasting its best both before and after Valentine's Day or to store for an extended period, Engeseth advises:
-- Purchase high-quality chocolate.
-- Keep chocolate at a constant temperature, close to room temperature 68 to 74 degrees Fahrenheit or slightly cooler.
-- Do not refrigerate or freeze chocolate.
"Even though chocolate has a long shelf life and is safe to eat, it may not taste the same or have the same creamy texture and texture if stored improperly," Engeseth says in a statement.