From Chocolatiers Wiki
You can also see the Truffles-Alternate Recipe for a softer ganache that works better for high volumes of truffles.
Makes 3-4 dozen truffles
Ganache - 2 cups chocolate chips - heavy cream: 1 cup for dark chocolate 2/3 cup for milk chocolate 1/2 cup for white chocolate - flavoring options: 2 tea bags 1-2 tsp. extract or spices 2-3 tbs. fruit juice/pulp or liqueur
Dipping - 1 and 1/2 cups additional chocolate chips
Decoration (optional) - different type of chocolate for drizzling - coco powder - minced nuts - sprinkles
1. Set up a double boiler with 2-3 inches of water in the bottom pot. NOTE: the top boiler should never be too hot to touch.
2. Pour the cream in the top pot, and heat until it begins simmering gently.
3. Add your flavoring. Note that the final flavor should be slightly more prominent than desired, since the ganache won't be as strong once you add chocolate. For spice, extract, or zest: add 1-2 tsp. in small intervals, frequently sampling the cream. For liqueur or fresh fruit juice/pulp: start with less cream and slowly add in 2-3 tbs. Be careful when adding citrus, as the cream is likely to curdle. For tea: cut 2 teabags and stir in the contents. Let them steep in the cream for 4-5 minutes. Strain out the tea leaves, then return the cream to your double boiler.
4. Turn the heat to low, then stir in chocolate chips one small handful at a time. Be sure that the existing chocolate is mostly melted before adding another handful.
5. If the top pot becomes too hot to touch or the chocolate takes on a gritty texture, immediately remove it from heat. Stir vigorously to cool the ganache before adding the rest of your chocolate. (Science: chocolate has six crystalline states, so it must be tempered very carefully if you want smooth and velvety truffles. Otherwise the molecules will separate too quickly, leading to easily melting or crumbly chocolate.)
6. Once all chips are melted, your ganache should form smooth, quickly disappearing peaks. Remove the top pot from heat and let sit for 5-10 minutes.
7. Once cool, wipe all the water off the edges of the pot, so it doesn't drip into your chocolate. (Science: when chocolate absorbs moisture, fats and sugar crystals "bloom," or rise to the surface. This leads to a whitish sheen and an oily texture, which you may see on old chocolate bars- it's perfectly safe to eat, though.)
8. Pour the ganache into a ziplock bag. Place in the freezer for 45-60 minutes, or until the ganache is moldable. If the mixture becomes too solid, let it sit at room temperature until it softens.
Balling and Dipping
1. Prepare a baking sheet with wax paper.
2. Cut off a 3/4" triangle in one corner of the bag. Squeeze out truffles one ball at a time onto the wax paper by pinching the edge of the bag with both hands. For perfect spheres, gently roll the balls between fingertips. If the truffles do not hold their shape, return the ganache to the freezer.
3. Put the completed baking sheet in the freezer so the ganache balls can harden.
4. Put aside 5-6 chips from the dipping chocolate. Melt the rest in your double boiler over very low heat. Once the chocolate is mostly melted, remove from heat and stir several minutes until mixture is smooth.
5. Toss in the extra chocolate chips without stirring. (Science: these "seed crystals" act as a template to ensure the melted chocolate cools into the right crystalline state.)
6. Using two forks or a candy-dipper, dip your balls in the pot of melted chocolate and place them on a clean sheet of parchment. Be sure to coat the ganache completely, or the truffles won't harden properly.
7. If you like, you can roll your truffles in cocoa powder, sprinkles, or minced nuts. For an elegant-looking truffle, use a fork to drizzle stripes of melted chocolate on top. Melted white chocolate can easily be dyed with food coloring.
8. Put the completed truffles into the fridge for 10 minutes, or until hard.
9. Pick off the bits around the edges, and store your truffles between sheets of wax paper. Unless they are flavored with fruit, they will last in the freezer for up to several months.