Brew Day Part 4 – Boiling
All we’ve done has lead up to this – the boil.
The simple answer is to clean the beer and make it safe to drink. Boiling your wort gets rid of bacteria that would cause your beer to be undrinkable. In addition to that, it will increase the alcohol content of your beer. By boiling your beer for 60-90 minutes, some of the total volume of the wort will decrease through evaporation. That makes the sugars more concentrated and eventually the beer higher in alcohol content. You could, in theory, skip the boil step and go straight to fermentation but you’d likely have a beer that was very watered down and potentially full of bacteria.
Most beers will have you boil for 60 minutes but in some cases, it is better to do a 90 minute boil. One of those cases is when your grain bill includes pilsner malt. Pilsner malt causes a higher frequency of dimethyl sulfide (DMS) which causes one of the most common off-flavors in beer – the creamed corn smell/taste. The longer you boil, the more DMS you boil off.
This is another (mainly) boring parts of the brew days because it takes so long to bring your wort to a boil. Imagine how long it take is boil a few quarts of water. Now increase the size greatly and instead of water, you’re boiling sugar water (wort). That’s why you increase your burner fire power. Once you start making 10 gallon batches, it would take forever to reach boil if you are using weak equipment. Even with a strong burner, it will take awhile for the wort to boil.
That’s when the excitement starts. The ‘hot break’ happens when the wort first starts to boil. The hot break causes the water level rise quickly and to the point where it will boil over. There are ways to fight the hot break but sometimes it is just too much to stop. Decreasing the heat first option but it’s not always a reliable option as you need to keep the heat at a certain level to maintain the boil for this long. Some also use something such as the mash paddle to go over the top of the boil kettle to pop the bubbles as they rise. This again is effective but not always reliable. Another way is to spash cold water on the bubbles to help bring it down. I often use a spray bottle with very cold water. It effectively knocks down the bubbles without adding too much water volume. I use a combination of all three methods when I brew and still have issues with the hot break a lot of the time.
Once the beer starts to boil, it’s time to think about adding in the extra ingredients to will form the taste and characteristics of the beer. Mainly it’s time for the hops to be added.
Hops are very important to final taste, smell and bitterness of your beer. There’s a wide variety of types of hops that have different uses, flavors and aromas. The style of beer you are making often determines what hops that you use. There’s so much to say about hops that I won’t go into it all now, just the basics.
Hops are a main component to the bitterness of a beer. The bitterness is measured in International Bitterness Units or IBUs. The higher the IBUs the more bitterness from the hops. Each type of hop has specific characteristics that determines how many IBUs it will contribute to a beer when used.
The longer a hop is in the boil the more IBUs it contributes to the beer but likewise, the longer the hops are boiled, the less flavor and aroma they contribute. For that reason, hops are split up into three categories – bittering, aroma and both. Bittering hops are typically added early in the boil, usually around 60 minutes. These hops contribute a large part of the total IBU count but little of the aroma. Other hops are added at various times during the boil – sometimes 30, 20 or 15 minutes. These hop additions will also add significant bitterness but also contribute more to the flavor and aroma of the beer. Finally hops are added late in the boil at 10, 5, 3 or every 0 minutes. These hop additions are meant to bring out strong hop flavor and aroma. These are the hop additions that can really make a beer stand out especially in hop heavy styles like IPAs.
For Siska’s Coconut Porter, hops are not a huge part of the flavor profile of the beer. However, hops are needed in this beer to help balance the maltiness of the beer. I added 1.75 oz of Magnum hops for 60 minutes to add 38.5 IBUs. 1 oz of Cascade hops were added at 30 minutes to give more bitterness (7.2 IBU) and some aroma. Finally 1 oz of Hallertauer hops were added at 5 minutes to provide a lot of flavor and aroma but little bitterness (1.8 IBUs)
Hops aren’t the only thing that you add during the boil. Other ingredients can be added as well because, as you know, boiling sanitizes everything. These ingredients can be used to enhance flavors such as the use of peppercorns and coriander in a saison. Or they could be used to enhance the beer making process.
Two things that I add to all my beers now are irish moss and yeast nutrients. I add half a teaspoonful of Irish Moss to the boil with 15 minutes left. Irish Moss is a clarifying agent to help make the beer look clearer. I add 2 teaspoonfuls of yeast nutrients into the boil at 15 minutes. Yeast nutrients are food for the yeast and helps the yeast get off to a quick, vigorous start, another trait that helps make your final product better.
Finishing Up The Boil
So you’ve added all your hops, fought off the hot break and boiled for 60-90 minutes. What’s next? Turn off your burner, it’s time to cool it down. You’re first instinct might be to put out all the hops and goodies (if you’re using hop bags), but you should wait to do that. You might be able to extract some more flavors while you cooling your beer. Which brings me to my next post – cooling your beer and pitching the yeast.