In rare cases, when chocolate melts, it becomes a dry and rough mass instead of a smooth and shiny mixture. To prevent this issue, use clean and dry bowls and metal utensils since chocolate seizes once it comes into contact with water. Also, melt chocolate in a double boiler over simmering water, but not boiling. Do not cover the saucepan with a lid. It prevents any condensation of water on the inside of the lid and bowl.