A tubular heat exchanger that heats wort quickly and efficiently, allowing it to boil vigorously in the kettle.

Calandria can be internal or external. An internal calandria is a bundle of tubes in which convection forces the wort through the tubes, where it is superheated by steam. An external calandria is attached to the kettle and wort is pumped out of the kettle, through the calandria, and then back into the kettle. 

Because a calandria provides a larger surface area for heating wort than other heat sources, such as direct fired kettles or steam jackets, it can reduce boil times up to 30%, which lowers energy costs for breweries.