Wort boiling process



It begins to be heated and boiling when wort goes into kettle tun. Generally, the boiling time is calculated when wort temperature rises up to 100 degree C.
The reasonable boiling time is about 70-90 min.
The whole boiling process can be separated into 3 stages:  preheat, initial boiling and boiling.
For preheat, wort is cooled naturally during lautering process. It needs long time if heat the wort after whole lautering process is finished, so preheat has the function of heat preservation, or slow heating.
For initial boiling, it should be no more than 30 minutes. Spraging in lauter tun is still in progress so steam amount is not so big, initial boiling is prepared for next stage.
For boiling, the wort is in drastic boiling because the steam amount is maximum. It is better that boiling intensity is about 8%-12%. It will increase the hops utilization; coagulate proteins, then to make sure the wort is clear and bright. Or it will cause some off-flavor.