Editing Brewing (section)

===Brew kettle or copper===
[[File:Brasserie La Choulette 12-11-2006.jpg|thumb|Brew kettles at Brasserie La Choulette in France]]

Copper is the traditional material for the boiling vessel for two main reasons: firstly because copper transfers heat quickly and evenly; secondly because the bubbles produced during boiling, which could act as an insulator against the heat, do not cling to the surface of copper, so the wort is heated in a consistent manner.<ref name="Brew p272">{{cite book |url=https://books.google.com/books?id=cr9Pv0gefCQC&pg=PA272 |title=Brewing |page=272 |author1=Michael Lewis |author2=Tom W. Young |publisher=Springer |year=2002 |isbn=9780306472749 |access-date=19 November 2015 |archive-url=https://web.archive.org/web/20160511062855/https://books.google.com/books?id=cr9Pv0gefCQC&pg=PA272&dq |archive-date=11 May 2016 |url-status=live }}</ref> The simplest boil kettles are direct-fired, with a burner underneath. These can produce a vigorous and favourable boil, but are also apt to scorch the wort where the flame touches the kettle, causing caramelisation and making cleanup difficult. Most breweries use a steam-fired kettle, which uses steam jackets in the kettle to boil the wort.<ref name="Bamforth 2011" /> Breweries usually have a boiling unit either inside or outside of the kettle, usually a tall, thin cylinder with vertical tubes, called a calandria, through which wort is pumped.<ref name="Hampson 2011">{{cite book|url=https://books.google.com/books?id=gYVLHMmplRcC&pg=PA201|title=The Oxford Companion to Beer|page=201|author=Tim Hampson|publisher=Oxford University Press|date=9 September 2011|isbn=9780195367133|archive-url=https://web.archive.org/web/20160502054817/https://books.google.com/books?id=gYVLHMmplRcC&pg=PA201|archive-date=2 May 2016|url-status=live}}</ref>