Some general rules about melting chocolate :
– Take your time. Dark chocolate can withstand high temperature than milk or white chocolate, but it’s always best to heat chocolate gently.
– Chopping chocolate before melting means the heat will be evenly distributed, and the chocolate will melt quickly with little fuss.
– Be very careful liquid away from melting chocolate. Chocolate is composed of solids suspended in cocoa butter. Melting the chocolate transforms the cocoa butter into liquid, and the solid particles glide easily through this cocoa butter base. But just a few drops of water, or any liquid, will be absorbed by the solids and cause them to cling to each other. When this happens, the chocolate seizes, or becomes stiff and difficult to stir. Once chocolate has seized, your only option is to add more liquid and make Chocolate sauce.
3 different methods for melting chocolate :
Method 1 – Water Bath
Set a metal bowl in the center of a wide deep skillet half full of simmering water. With this arrangement, you can easily see if the water is becoming too hot and turn down the heat as necessary. However, you do need to be cautious that no water splashes into the chocolate.
Method 2 – Double Boiler
Simply set a metal bowl over a saucepan, as long as there’s no gap (such as pour spout on the pan) for steam to escape through. (Steam can cause condensation on the bowl, so that water runs into chocolate). Many cooks believe that the bowl holding the chocolate should not touch the water, but that’s a myth: It’s fine for the bowl to touch the hot water beneath. The steam rising under the bowl is actually hotter than boiling water. But the water doesn’t have to reach a boil; the bowl just needs to be warm to melth the chocolate. To avoid being burned by trapped steam, be careful when you remove the bowl or the top of a double boiler.
Method 3 – Microwave
The microwave works wonderfully for melting chocolate as long as you heat it for very short periods of time and stir well after each one. The problem with microwaving is that the chocolate will retain its shape when melted. This means you can’t determine whether or not the chocolate is melted by how it looks. Microwave in short bursts of 10 to 30 seconds (depending on the wattage of your microwave) and stir the chocolate after each burst until just melted.
Method 4 – Heated Cream
When you’re working with chocolate and cream – making a ganache, for example – most recipes tell you to put the chopped chocolate in a bowl, heat the cream, and pour it over the chocolate. But if the cream isn’t hot enough or the chocolate isn’t finely chopped, the chocolate may not melt completely. Pastry chef, Jim Dodge uses this foolproof method: Finely chop the chocolate and have it in a bowl next to the stove. Heat the cream in a saucepan. When the cream comes to a simmer, remove the pan from the heat. Add the chocolate to the pan, let stand, then stir until melted and smooth. The residual heat fromm the pan keeps the cream at the right temperature while the chocolate melts.
Source : The Essence of Chocolate – John Scharffenberger and Robert Steinberg