Result: Instead of having a smooth, creamy, luxurious consistency, your chocolate is grainy, separated, or scorched.
The best way to melt chocolate is to go slowly, heat gently, remove from the heat before it’s fully melted, and stir until smooth. If using the microwave, proceed cautiously, stopping every 20 to 30 seconds to stir. If using a double boiler, make sure the water is simmering, not boiling. It’s very easy to ruin chocolate, and there is no road back.
Associate Food Editor Julianna Grimes recently made a cake but didn’t pay close enough attention while microwaving the chocolate. It curdled. "It was all the chocolate I had on hand, so I had to dump it and change my plans."