Melting Chocolate

Directions for melting chocolate generally say something like "in a bowl over barely simmering water." The problem is that chocolate scorches (its flavor changes and degrades) at a relatively low temperature, like between 110° and° 120 F. Water is seen to begin to simmer at around 150°F, which is when steam begins to become visible coming off the surface.

Unfortunately, not only is this situation difficult to use, but the detection of it is unreliable. If the water comes near or to a boil, the temperature at the condensation interface - the bowl with the chocolate - will approach the boiling point of water, 212° F. Whether there is visible steam rising from a pot of water depends upon the temperature of the surrounding air: if a pot is surrounded by very hot air, by virtue of being on a hot stove or just over a hot fire, the steam will not be visible.

Furthermore, because the heat transfer to the bowl of chocolate is only accomplished with steam, which cannot be permitted to be efficient so as to not scorch the chocolate, it is simply not possible to melt chocolate with any rapidity.

Therefore, we find that it is best to melt chocolate in a double-boiler arrangement where the bowl containing the chocolate rests in the water. The water in the pot is never allowed to exceed about 120°F - you should always be able to hold your hand against the outside pot. The direct contact with water allows a more efficient heat transfer, so the chocolate can melt more rapidly, but the chocolate is safe from scorching if the water isn't hot enough to do so.

For white chocolate, the water temperature should be slightly lower, about 110°F.