Two melting techniques we've found to be foolproof.
Melting chocolate can be a dangerous game—let it get too hot and it will break, becoming irretrievably grainy. A heavy-bottomed skillet over a very low flame does the trick, but not every burner is capable of maintaining a low enough heat. Here are two melting techniques we’ve tested again and again and found to be foolproof.
1. Bring a pot of water to a near simmer over low heat; set a large heatproof bowl (the edges should overhang the pot for easier removal) over it, making sure that the water does not touch the bottom of the bowl (to avoid overheating the chocolate).
2. Add 8 ounces chocolate chips (or bar chocolate chopped into ½-inch pieces) and heat, stirring occasionally with a rubber spatula, until uniformly smooth and glossy, about 10 minutes (adjust the cooking time as necessary for larger or smaller amounts of chocolate). If the recipe calls for melting the chocolate with butter, add both to the bowl at the same time.
1. Put 8 ounces chocolate chips (or bar chocolate chopped into ½-inch pieces) in a large microwave-safe bowl. Microwave at high power for 45 seconds.
2. Stir with a rubber spatula, scraping down the sides of the bowl, then heat 30 seconds more. Continue heating and stirring for 15-second intervals until the chocolate is uniformly smooth and glossy. (To melt smaller or larger amounts, decrease or increase the initial microwaving time by 10 seconds for every 2 ounces of chocolate.) If the recipe calls for melting the chocolate with butter, do not add the butter until the chocolate is almost completely melted. (Adding the butter earlier will cause it to splatter.)