Blowing sugar is one of the most demanding skills in the pastry chef's repertoire. The sugar is only workable within a narrow range of temperatures, right at the upper limit of what a gloved hand can tolerate. Several pieces of equipment are required to warm and cool the sugar as needed, and creating attractive pieces of blown sugar requires a high level of skill and an artistic eye. Still, a determined enthusiast who is willing to invest the necessary time and money, and is prepared to live with the inevitable burns, can learn the necessary skills.
Pour the sugar and water into a pot or saucepan, and bring it to a boil over a medium-hot burner. As the sugar boils, various impurities will foam up to the surface. These should be removed with a clean metal spoon or silicon spatula.
Brush the sides of the pot with a wet pastry brush wherever crystals form. If left unchecked they will cause the entire pot of melted sugar to recrystallize.
Check the temperature of the sugar once it is clear and isn't producing any impurities. Once it reaches 110 degrees C, add the corn syrup and cream of tartar. These help convert the sugar to glucose and fructose, which are less prone to crystallising while you work.
Raise the heat and bring the sugar mixture up to 149 degrees C. Then remove the pot from the heat, and immediately set it in a shallow pan of cold water to halt the cooking process.
Pour the prepared sugar onto the silicon mat. Allow it to cool for about 30 seconds, then begin folding the cooled edges back into the middle of the mass of sugar. Use a metal spatula or spoon to do this, or simply fold the silicon mat from each edge to the middle.
Knead the dough through the silicon mat, or with the metal utensil, until it has cooled enough to be handled with a gloved hand. Turn on your heat lamp and position it so it warms the sugar. Stretch the mass of sugar three or four times into a long rope, folding it back on itself each time until it has a glossy, satiny appearance. Proceed to blowing the sugar.
Cut off a piece of sugar slightly larger than a golf ball. Hold it in the palm of one gloved hand, and use the thumb and fingers of your other hand to shape it into a hollow ball.
Heat the edges of the hollow part of the ball with your gas torch briefly. Insert the nozzle of the sugar pump into the hollow, and press the warmed edges firmly around it to make a seal.
Squeeze the pump three or four times to begin blowing air into the sugar. It should start to expand slightly. Holding the sugar close to the heat lamp, gently expand it until it is roughly the size you want.
Stretch and bend the sugar into your desired shape. Keep the sugar warm under the lamp while you work with it, and if necessary soften it with a torch or paint stripping gun. Once each section of the sugar has reached the shape you want, cool it quickly with the hair drying set to cool.
Remove the nozzle of the sugar pump by heating it with the torch and using a pair of pliers to gently pull it out. Soften the edges of the resulting hole with your torch or heat gun, and then seal them together.
Combine blown and pulled pieces of sugar by heating them gently, and securing them in place with a small bead of melted sugar. Continue creating pieces in the same manner until your design is complete.
To make coloured sugar, separate a portion of the hot sugar once it is poured out onto the silicon mat. Brush a small amount of colouring onto the sugar and incorporate it by kneading and stretching. Some pastry chefs prefer to use a warmed, lightly oiled marble slab instead of a silicon mat. Either technique is appropriate, but silicon mats lower the cost of sugar work for a novice. Sugar-blowing pumps can be obtained from speciality suppliers online. Alternatively, the pumps used for blood pressure testing can be easily modified for sugar work. Prepared sugar can be reheated in the microwave. Cut an inexpensive silicon mat to fit the glass tray of your microwave, and heat the sugar on this at 15 second intervals until it returns to a working temperature. Use another piece of silicon mat to knead it until the heat is evenly distributed.
Hot sugar can cause very serious burns. Make sure that children are kept away from the work area at all times. Keep a first-aid kit close to hand, and ensure that there is a sink nearby so that cold water can be applied immediately to any burns.