After the barley has sprouted, then halted of sprouting further and has finally become malt, adjuncts are added and it is then ground to grist. The grist is then mashed, that is, mixed with hot water and steeped, a complex and slow heating process that enables enzymes to convert the starch in the malt into sugars. Temperature of the mixture is usually increased to 78°Celsius. At set intervals (notably when the mixture has reached a temperature of 45°C, 62°C and 73°C), the heating is briefly halted.
At set times, hop is also usually added to the mixture. Hops are generally added to a wort in two parts: the bittering hops are boiled for around an hour to an hour and a half, and the finishing hops are added toward, or after, the end of the boil. Hop cones contain resins, which provide the bittering and take a long boil to extract, and oils, which provide flavor and aroma, but evaporate quickly. Generally speaking, hops provide the most flavoring when boiled for around 15 minutes, and the most aroma when not boiled at all (i.e., added after the boil, a process called dry hopping.) At the end of the mashing, the hot wort is decanted or filtered, boiled, cooled, and the yeast is added to start the fermentation.
The grains known as adjuncts which may be added to the malted barley include wheat, corn, and rice. They are used to create varietal beers such as wheat beer and oatmeal stout, to create grain whisky, or to lighten the body (and cut costs) as in American-style lagers.