To some this article is trivial because you already boil your wort. But there may be some things that you did not know about the boiling process. There are some small kits out there that actually do not require you to boil the wort. I highly recommend you don’t use these because of the huge contamination risk they present. But why do we boil the wort? The thing that most brewers will answer that question with is, “to boil the hops and extract the hop flavor”. While that is one of the main reasons we boil our wort there are many more just as important effects that the boil has on the quality of our finished beers.
First of all, since most people who have brewed have added hops to a boil they at least know that something is happening in the boil that is important to adding hop flavor to your beer. To be more specific, the boil is extracting the Alpha acids and other oils out of the hops. The alpha acids are what bitters you beer and the oils aid in the hope flavor in the beer. Along with the bitterness, the boil also extracts flavor and aroma from the hops. The reason the hops are boiled for different lengths is that you can lose hop flavor and aroma the longer you boil the hops. So some are added at the beginning middle and end of the boil to achieve a rounded out hop profile.
As well as releasing the hop characteristics into the beer the boil also helps release the flavors of any special ingredients into your brew. Ingredients like fruit, wood chips, sugars, and spices are boiled to help get the flavor to permeate the beer. some special ingredients like fruit are sensitive to boiling and should only be added in the last fifteen minutes of the boil.
Another very important reason that you boil the wort is because to boiling process helps coagulate different proteins and tannins that can be bad for the flavor in your beer. When these are coagulated in the hot wort it makes them larger and heavier. When you cool the wart rapidly it’s much easier for them do drop out of the solution into the bottom of your fermentation bucket.
There are also some chemicals that boiling can aid in vaporizing and removing from your beer. Standard tap water contains chlorine that when heated will vaporize and leave your beer. Make sure that you don’t cover your beer during the boil. So that you allow anything that is getting boiled off to escape your brew.
The most important reason that we boil our beer is to sterilize the beer for fermentation. The easiest way to add special ingredients, especially fruit, is to add them in the last fifteen minutes of the boil to ensure they are sanitized. You don’t want to boil fruit too long or you can begin to lose some of the flavors the fruits have to offer. Any specialty ingredient can be added in the end of the boil so that you don’t have to find some clever way to sanitize them later.
60 min boils are not always long enough for your beers. Sometimes lighter beer could actually benefit from a 90 min boil. Because the flavor profiles are so delicate in lighter beers the removal of the proteins and tannins is that much more important as where they could be hidden in heavier beers. Sometimes more hop bitterness is wanted in a beer so boiling an extra thirty minutes can get more alpha acids out of the hops Making your beer that much more bitter. Some high gravity beers like the Dogfish head 120 min IPA are boiled for, you guessed it, 120 minutes. However long you boil for think about the affects the boil will have on the final product and have fun.