Tempering is the heating-and-cooling process that stabilizes chocolate, making it satiny and snappy when broken. Chocolate can only be tempered once; pour the leftover tempered chocolate from this recipe onto a baking pan to harden, then store and use as baking chocolate.
Instead of melting the chocolate in the microwave, you can alternatively melt it over a water bath. To do so, fill a saucepan with 2 inches of water, and bring to a simmer; turn off heat. Set bowl with two-thirds chopped chocolate over pan, and stir gently with a rubber spatula until chocolate has melted and an instant-read thermometer registers 118 degrees.Remove bowl from pan. Add reserved chopped chocolate. Stir constantly, bringing chocolate up sides and back down into bowl, until temperature cools to about 86 degrees. Drizzle a thin line of chocolate on a stainless-steel surface to see that it is tempered, then return bowl to saucepan; stir occasionally to maintain temperature between 86 degrees and 89 degrees, returning to heat, if necessary.