Decorating desserts with shapes made out of chocolate makes them extra special. Make shapes with melted chocolate to give away as sweets, decorate a cake, or add a touch of whimsy to an ice cream sundae. You can use different types of chocolate to make shapes in a range of colours and tastes. There is such a wide range of moulds available, you can make an endless array of different chocolate shapes.
Chop the chocolate and divide the amount in half. Fill the double boiler with water and bring it to a boil, then turn down the temperature to keep the water at a simmer.
Add half of the chocolate to the top of the double boiler and continue to heat the chocolate, at a simmer, until it melts. Stir the chocolate with a silicone spatula to prevent it from burning. Check the temperature of the chocolate with the chocolate thermometer. Heat it until it reaches 46.1 degrees C (115 degrees F), then remove the top of the double boiler from the heat, wiping it dry on the bottom to prevent any moisture from affecting the chocolate.
Mix in the remaining half of the chopped chocolate, stirring constantly with the spatula. Continue to stir the chocolate for about 15 minutes, until all of it has melted and the temperature of the mixture reaches 32.2 degrees C (90 degrees F).
Put a small amount of the chocolate on a spoon and place it in the fridge for one to two minutes. It should come out smooth, not tacky, and a little shiny. If not, continue to stir the melted chocolate for one to two more minutes. At this point, you have tempered your chocolate, which will prevent it from looking greasy, dull or from separating when you pour it into your moulds.
Pour the chocolate into clear chocolate moulds of your choice, using a funnel to prevent spills. Chill the moulds in the refrigerator until the chocolate turns solid. Pop the shapes out of the mould.
Make freehand chocolate shapes using a pastry bag. Fill the bag with the melted chocolate and line a baking tray with an acetate baking tray. Draw shapes of your choice on the sheet by squeezing the chocolate through the tip of the pastry bag. Allow the shapes to harden, on the sheet, in the refrigerator until firm. Remove the shapes with a spatula.
Place biscuit cutters on an acetate-lined baking tray and fill them with 3 to 6 mm (1/8 to 1/4 inch) of chocolate. Put them in the fridge to harden. When hard to the touch, gently remove the biscuit cutters by tapping the chocolate shapes out of them or pressing lightly in the centre of the shape to slide it out of the cutter.
Cut-out shapes of melted chocolate with biscuit cutters or a knife. Line a baking tray with an acetate baking tray. Pour the melted chocolate on the sheet and spread it in a layer about 3 mm (1/8 inch) thick. Allow the chocolate to stiffen, but not completely harden. Dip the biscuit cutter or knife in warm water to easily cut through the chocolate then dry it completely. Cut out shapes with the biscuit cutter from the chocolate or cut out freehand shapes with the knife. Place the shapes on an acetate-lined baking tray and wrap the top tightly with cling film to prevent the shapes from curling when they cool. Chill the shapes until firm in the fridge.
You can substitute milk or white chocolate, for the semi-sweet, initially heating it to 43.3 degrees C (110 degrees F) -- instead of 46.1 degrees C (instead of 115 degrees F) in the double boiler. When stirring in the chopped chocolate, wait until it reaches 31.1 degrees C (88 degrees F) -- not 32 degrees C (90 degrees F) -- before testing the chocolate. Use oil-based food dye to colour white chocolate as water-based dye can turn the chocolate grainy and unusable.
Never heat chocolate over direct heat, which will burn the chocolate. Once burnt, you must throw away the chocolate and start again. Keep water away from chocolate when heating as it can ruin its texture and render it unusable to make shapes with.