Some beer styles call for wheat to be mixed with the barley.
This liquid is called wort . The cooking of the malted barley converts the starches in the barley into fermentable sugars, this the wort is very sweet. The wort is then separated from the barley grains and put into the boiling kettle. The wort is boiled for anywhere from one hour to several hours. During the boil, flavoring hops are added to impart some bitterness to balance the swetness of this barley-infused water.