In years gone by, scalding milk was critical because heating the milk nearly to the boiling point kills dangerous bacteria. Although today's milk is pasteurized and requires no heating to ensure safety, scalding is still useful because hot milk dissolves sugar, melts butter and improves the flavor of many dishes while cutting down the cooking time. Scalding milk, easily done using one of three simple methods, is especially helpful in breadmaking because it dissolves yeast and distributes the fats evenly throughout the dough, creating lightweight, flavorful bread.
Pour the milk in a heavy-bottomed saucepan to scald the milk. Avoid lightweight pans because they scorch easily. Turn the burner to medium. Heat the milk, stirring often, until the milk begins to steam and tiny bubbles appear around the inside edge of the pan.
Measure the milk into the top of a double boiler, which heats the milk gently and helps prevent scorching. If you don't have a double boiler, you can measure the milk into a heat-proof glass bowl, then place the bowl inside a large saucepan filled with simmering water. Heat the milk until steam develops and bubbles form around the edges. Stir frequently.
Place the milk in a microwave-safe cup or bowl to scald it in the microwave. Heat the milk on high power until bubbles form at the edge of the cup. Stir the milk once or twice during the cooking time to prevent a skin from forming on the surface of the milk. Heating time varies depending on the amount of milk and the wattage of the microwave, but scalding 1/2 cup of milk takes approximately 60 to 90 seconds.
Cool scalded milk to 105 degrees Fahrenheit or lower before adding yeast. Otherwise, the hot milk may kill the yeast and prevent the bread from rising properly. If you don't have a thermometer, cool the milk until it is approximately body temperature -- neither too hot or too cold. Always cool scalded milk before adding it to eggs because the hot milk may cook the eggs.