Immersion Chiller

A metallic coil (typically copper but occasionally stainless steel) which is used to rapidly reduce the temperature of the hot wort at the end of the boil to quickly achieve the desired temperature for pitching the yeast.  It is typically made from copper but stainless steel versions exist.  It is typically fitted with water inlet and outlet ports.  It permits cold or pre-chilled water to be circulated through the coil while it is immersed in the hot wort contained in the brew kettle.  The high specific heat of water and the high heat conductivity of the metal used, allow for the rapid removal of heat energy from the brew kettle while preserving the sterility of the boiled wort.  It can be used in conjunction with a whirlpool attachment to increase the efficiency of the heat transfer.