TEPHRA AND PYROCLASTIC ROCKS. The rapid eruption of expanding gases results in the obliteration and fragmentation of magma and rock. The greater the explosivity, the greater the amount of fragmentation. Individual eruptive fragments are called pyroclasts (fire fragments).Tephra (Greek, for ash) is a generic term for any airborne pyroclastic accumulation.Whereas tephra is unconsolidated, a pyroclastic rock is produced from the consolidation of pyroclastic accumulations into a coherent rock type.he greater the explosivity, the greater the amount of fragmentation. Individual eruptive fragments are called pyroclasts (fire fragments). Tephra (Greek, for ash) is a generic term for any airborne pyroclastic accumulation.
Test the temperature of the milk with an instant-read thermometer once the milk has begun to steam and show small bubbles. Milk is considered to be scalded once it exceeds a temperature of 180 degrees F. Select a heat-proof measuring cup that is capable of holding at least twice as much milk as you wish to heat.
How to Scald Milk. Some baking recipes call for scalded milk; that is, milk brought nearly to a boil and then cooled down. Scalded milk makes yeast breads lighter and sponge cakes springier. It also helps dissolve sugar and melt butter, and extracts the most flavor from vanilla beans, cinnamon, citrus peels, and other flavor agents.