The Double Luck Brewing Process

The Double Luck Brewing Process:

Boiling

URL: http://www.doubleluck.com/things/brewery/process/boiling.php
Last modified: Wed, 27 May 2009 13:22:58 -0600
Copyright © 1999-2010 Larry Bristol - All rights reserved.

Boiling
Boiling

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The sweet wort is collected into the third 14 gallon stainless steel kettle and quickly brought to a rolling boil. As the wort begins to boil, certain complex chemical reactions occur that cause a great deal of foam to be produced. It is important to use a vessel that will hold a lot more than the volume being boiled, because it has this unfortunate tendancy to boil over! Think about the consequences of spilling hot sugary liquid all over the place, especially if brewing in a location that is the principle domain of a significant other. This foam will soon fall back into the liquid, precipitating into a sludge like material called hot break, that will eventually be left behind. During the boil, other chemical reactions occur that improve the color, clarity, and overall appearence of the brew. The rolling boil is continued for approximately 90 minutes, reducing the volume of liquid to our target batch size.

Hops are added at appropriate times during the boil, changing the sweet wort into what we now call bitter wort. Hops contain complex organic chemicals known as alpha acids that are extracted during the boil. These alpha acids impart a bitterness to the brew, necessary to offset the sweetness that will be left by non-fermentable sugars. Since they are not very soluble, the amount of bitterness extracted from the hops depends on the length of time that they are boiled. On the other hand, prolonged boiling will drive out other organic chemicals that impart hop flavors and aromas. For this reason, most recipes will call for hops to be added in multiple courses during the boil so that we get bitterness, hop flavors, and hop aromas in appropriate amounts.

Hops intended to impart bitterness are boiled the longest (60 to 90 minutes). This maximizes the amount of alpha acids that are extracted, but most of the hop flavor and aroma is lost. Hops intended to impart flavor are boiled for a shorter time (10 to 15 minutes). While there is far less extraction of alpha acids, there is also less loss of the substances that impart hop flavors. After boiling even for this short time, however, most of the substances that provide hop aromas will be lost. Hops intended to impart aroma are boiled the least (less than 5 minutes). In most cases, in fact, aroma hops are added at the very end of the boil so that they merely steep in the hot wort before it is cooled, and are not actually boiled at all. Little or no alpha acid is extracted. Aromatic oils and substances that provide hop aroma and flavor are the only items we get from these hops. Another method to use hops is to add them to the keg of beer after fermentation has occurred. Called dry hopping, this technique adds a dramatic amount of hop flavor and aroma to the finished beer. Dry hopping cannot be done in bottled beer.

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Hops are available to the homebrewer in three forms. Approximately 1 ounce of each form is shown to the right.

Whole hops (sometimes also known as "loose hops") are simply dried hop cones. The cones are likely to break apart into the individual petals when the hops are dried.
Hop plugs are dried hops that have been tightly compressed into a puck. During the boil, the puck will break apart returning to the original form, leaving intact petals. One convenience of this form is that each puck is a premeasured 1/2 ounce.
Hop pellets are dried hops that have been pulverized and then compressed into small pellets. During the boil, the pellets will break down into mush that will settle to the bottom of the kettle. The pellets are easy to measure and have improved storage qualities over the other forms. In addition, while the hop petals remaining from whole hops or plugs must be strained out, it is not technically necessary to strain the residue left from hop pellets after the boil has complete.

While there is a considerable difference among these forms in terms of their storage characteristics and convenience in use, they can otherwise be considered as identical. You can even mix the different forms of hops within the same batch. As will be seen shortly, having intact hop petals after the boil is complete is useful in subsequent steps. For this reason, it is a good idea for half of the hops used in a batch to be in either whole form or plug form.

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