After going to beer school at Siebel Institute you learn a few things about brewing that perfect beer. One of the keys to designing that great beer is balance. Without the correct bitterness your beer could be either too sweet or too bitter. Today we will focus on the correct IBUs for the style of beer you want to create. IBU stands for International Bittering Units.
Let’s start with stouts and porters. These styles typically have lower IBUs than your IPAs and pale ales. A stout that is between 5%-7% ABV contains 20-40 IBUs. We get this bitterness by the amount of alpha acids in the hop and how long we choose to boil these hops in the wort. A good bittering hop would be Magnum, Columbus, and Warrior because these hops have over 10% alpha acids in them. If you wanted to brew a higher gravity stout or porter, you would want to increase the IBUs to 60-80. The reason for this is to help balance out the sweetness with more bitterness from the residual sugars left behind after fermentation.
When it comes to IPAs they have higher IBUs than most normal beers. The reason for this dates back to the early 18th century when they were transporting beer from England to India. The hops are a natural preservative that kept the beer from going bad on the long trip across the sea. Naturally the more hops that were added the more bitter the beer was. This is how IPAs came about. IPAs range from 5%-9% ABV and have 40-60 IBUs unless you are making a double IPA, which will contain 60-100 IBUs.
There is, however, a somewhat objective measure we can use to describe at least one aspect of balance, and that is the IBU to gravity unit ratio, or BU:GU, which compares bitterness to malt character. It’s simply the number of IBUs divided by the number of gravity points. Gravity points are, in turn, the fractional part of the original gravity measurement: 1.050 is 50 points, 1.068 is 68 points, 1.112 is 112 gravity points, and so on. A bitter imperial IPA will have a ratio of one or more, while a malty style such as Doppelbock could come in at 0.5 or less. It’s not a perfect idea, but it’s a start.
So what can we do as homebrewers to promote that elusive concept called balance? Here are a few things I would recommend.
- Aim for an appropriate BU to GU ratio. The typical range is 0.5 for very malty styles to 1.0 for very hoppy ones. Depending upon the kind of finish you desire, you can tweak your grain bill and hops to adjust this number.
- Don’t be afraid of simple sugars, but remember that they ferment out almost completely, leaving behind no residual sweetness and creating a dry perception on the palate. Increasing simple sugars may require decreasing hops bitterness to retain balance.
- Similarly, choose a yeast strain that’s up to the task, and make sure to use an appropriately sized pitch of healthy yeast cells. Insufficient attenuation can leave a sweeter than desired finish.
- Watch out with fruit, spices, and flavorings. Unless you’re following an established recipe that you know you like, start with small quantities. These additives can deliver a surprising amount of character that the tongue perceives as completely out of proportion to what you actually added. There’s always the next batch if you want more.