Editing Brewing (section)

===Wort cooling===
After the whirlpool, the wort must be brought down to fermentation temperatures {{convert|20|-|26|C|F}}<ref name="Van den Steen" /> before yeast is added. In modern breweries this is achieved through a plate [[heat exchanger]].<ref name=Plate>{{cite book |url=https://books.google.com/books?id=0os_gIvG_ccC&pg=PA312|page=312|title=Handbook of Brewing|editor=William Hardwick|publisher=CRC Press|date= 15 Nov 1994|isbn=978-0-8493-9035-7 }}</ref> A plate heat exchanger has sereral ridged plates, which form two separate paths. The wort is pumped into the heat exchanger, and goes through every other gap between the plates.<ref name=Plate/> The cooling medium, usually water from a [[cold liquor tank]], goes through the other gaps. The ridges in the plates ensure turbulent flow.<ref>{{cite web|url=https://theengineeringmindset.com/how-plate-heat-exchangers-work/|work=theengineeringmindset.com|title=How Plate Heat Exchangers Work|author=Paul Evans|date=5 July 2019}}</ref>  A good heat exchanger can drop {{Convert|95|°C}} wort to {{Convert|20|°C}} while warming the cooling medium from about {{Convert|10|°C}} to {{Convert|80|°C}}. The last few plates often use a cooling medium which can be cooled to below the [[freezing point]], which allows a finer control over the wort-out temperature, and also enables cooling to around {{Convert|10|°C}}. After cooling, oxygen is often dissolved into the wort to revitalize the yeast and aid its reproduction.<ref>{{cite web|url= https://byo.com/article/aerating-wort-techniques/|work=byo.com|title=Aerating Wort Techniques|author=Jon Stika|year=2009}}</ref> 

While boiling, it is useful to recover some of the energy used to boil the wort. On its way out of the brewery, the steam created during the boil is passed over a coil through which unheated water flows. By adjusting the rate of flow, the output temperature of the water can be controlled. This is also often done using a plate heat exchanger. The water is then stored for later use in the next mash, in equipment cleaning, or wherever necessary.<ref name="Kunze 2004">{{cite book|author=Wolfgang Kunze |date=2004 |title=Technology Brewing and Malting|url=https://archive.org/details/technologybrewin00kunz |url-access=limited |publisher=VLB Berlin|isbn=3-921690-49-8|page=[https://archive.org/details/technologybrewin00kunz/page/n299 302]}}</ref> Another common method of energy recovery takes place during the wort cooling. When cold water is used to cool the wort in a heat exchanger, the water is significantly warmed. In an efficient brewery, cold water is passed through the heat exchanger at a rate set to maximize the water's temperature upon exiting. This now-hot water is then stored in a hot water tank.<ref name="Kunze 2004" />