Tips for New Brewers
Boiling the Wort
The kettle may be partially covered while heating the water to attain a boil more quickly. When the water begins to boil, remove the kettle from the heat source and add the malt extract which has been heated in a hot water bath, oven or dishwasher to make the syrup pour more easily. When the malt is thoroughly disbursed in the water return the uncovered kettle to the heat source stirring while bring the wort to a rolling boil. Until the boil is stabilized, it is prone to boil over, so watch it closely. With a really vigorous boil, you may need to spray the foam down with water from a spray bottle. Once the boil is stabilized, it is no longer necessary to stir the boiling wort.
Wort is boiled to: (1) destroy enzymes in the wort; (2) sterilize the wort; (3) remove by evaporation undesirable compounds in the wort; (4) extract bitterness from hops; and (5) to clarify the by coagulation of proteins and tannins (hot break).
Cooling the Wort
After the wort is boiled, it must be cooled to fermentation temperature before the yeast can be pitched (added to the wort). During cooling of twort, the clear wort will once again become cloudy. This is the result of the same protein and tannin interaction which was occurring during the hot break. Some of the compounds formed will remain in solution at high temperatures and only precipitate during cooling (cold break). The faster you can reduce the temperature, the better. A long, slow cooling period does not provide a good cold break which may result in a hazy beer. The wort should be cooled to fermentation temperature within one and one-half hours of the conclusion of the boil. This will provide a better cold break as well as inhibit bacterial growth.
So how does one cool the hot wort so quickly? Well, when doing a partial boil (2-3 gallons), the boiling kettle can be placed in a sink of ice water, changing the water as the ice melts. Then after racking the wort to the bottling bucket adding cold water to reach the 5 ¼ gallon level. Adding ice to the hot wort is not recommended because bacteria can survive in ice and therefore be transferred to the wort.
Wort chillers either immersion or counter-flow can also be used to quickly cool the hot wort to pitching temperature. For more information on wort chillers see Our Article on Wort Chillers.
At the conclusion of the boil, it is important to separate the solids which have broken out of solution and spent hops from the clear wort. The most practical way of doing this is by stirring the hot wort with a long spoon or paddle creating a whirlpool action. Then allow the solids to settle again forming a cone in the bottom of the boiling kettle. The clear wort can then be siphoned from the kettle. Although some brewers pour the wort through a funnel with a screen into the bucket, this practice is not recommended. This is dangerous if the wort is hot since hot wort hitting a cool carboy can cause the carboy to break. Also the hot wort will be aerated thus hastening oxidation of the finished beer.