This chapter is about boiling the wort.
Boiling with Malt Extract
Heat the wort to boiling uncovered, adding any brewing salts (gypsum, et al.) at this point. Remove from the heat source and add 1 or 2 cups of malt extract, stir until completely dissolved and return the wort to a boil. The boil does not need to be too aggressive. The hot break usually occurs during the first 5 to 15 minutes of the boil.
After 10 minutes, make the first ("bittering" or "boiling") hop addition. Begin timing your hour boil at this time. Continue to add hops at the intervals specified in your recipe. Be sure to remove your hops from the refrigerator several hours before brewing so that they may come up to room temperature before adding to the kettle.
Boil for 45 minutes and add 1/2 teaspoon of Irish moss. If using a immersion wort chiller, place the unit in the kettle now to allow 15 minutes of boiling for sterilization.
Continue to boil for 15 minutes.
Once again remove the kettle from the heat source, and add the remaining extract and adjunct sugars (if any) to the wort and stir to dissolve thoroughly and completely. The temperature should drop to about 170°F.
Allow the hot wort to remain at this temperature for about 10 minutes to sanitize the extract and sugars.
Cool the wort by any or all of the following methods:
- Begin the flow of cold water through an immersion chiller
- Add ice which was previously made by filling sterilized 1- or 2-litre PET (soda) bottles with water that had been boiled, allowed to freeze, and the plastic bottle cut off
- Place the brew kettle in a sink filled with ice water.
Siphon the wort into your fermenter, leaving the hot break, cold break, hops and other sediment in the kettle. Top up to the volume desired for fermentation. Aerate the wort well for 5 minutes.
Pitch the yeast when the temperature of the wort has dropped below 80°F (ideally around 76°F).
If dry hopping, wet the hops with a small amount of hot water (in effect making a quarter cup of "hop tea") before adding them to the cold fermenter. This will allow the aromatic oils to more easily dissolve out of the hops.
Hops are added into the wort during the boil to extract the bitterness from the hops.
Bittering hops Adding the hops at the start of the boil maximises the amount of bitterness extracted from the hops. The hops added at the start of boil contribute mainly to the bitterness of the beer, however the aromatic compounds are very soon boiled off and so these hops do not contribute much to the hop aroma of the beer.
Aroma hops The hops added towards the end of the boil retain more of the volatile aromatic compounds and this results in a beer with more hop aroma. But because of the short time the hops are boiled - not much bitterness is extracted.
During wort boiling sugar or syrup adjuncts may be added. The adjunct needs to be added so that enough time is given for the adjunct to be dissolved and sterilised.