Chocolate ganache is nothing but pure chocolate melted with a generous amount of boiling fresh cream. This smooth airless chocolate cream makes a lot of things possible. A benefit of chocolate ganache is that the high content of chocolate preserves the fresh cream so the final product can last in room temperature for a few days before events are celebrated.
If freshly mixed, while still in a liquid form, it can be used for pouring on cakes for coating or decoration etc. After a few hours of resting it will set in the perfect working condition for masking, sandwiching, piping and decorating cakes. If refrigerated, ganache will set hard like butter. This provides a good condition to coat cakes with rolling fondant.
Chocolate ganache can also be whipped to increase its volume and create milky, lighter color for truffle cream (for example). Whipping ganache can also reduce “heaviness” of a cake.