Understanding Hop Bitterness and IBUs
The main ingredients in beer are water, grain (wheat, barley, corn, oats, etc.), yeast, and hops. The hop flower (cone) is taken only from the female plant (humulus lupulus). Hops have a female and male component that allows for the creation of new hops without disturbing mother nature through genetic manipulation. Much of the funding for public hop-breeding programs comes from an organization called the Hop Research Council. It consists of six very large brewing companies: Anheuser-Busch, Adolph Coors, The Stroh Brewery Co., Suntory (Japan), Heineken (The Netherlands), and Labatt (Canada). Although hops are now used in almost every beer produced commercially, they were not the first ingredient used to produce bitterness and spicy flavors in beer. Hops were eventually settled on as a major ingredient in beer because of their bittering qualities, the variety of other flavors, and their antimicrobial qualities that favor brewers yeast but not the less desirable organisms.
Hops are used in beer to produce a bitterness that will adjust the final flavor profile on the drinker’s (you) palette. A beer without hops would be very sweet and cloying. It is important to realize that the amount of bitterness measured in the beer is not the same as the perceived bitterness as the beer is consumed. The way a beer is brewed has an impact on the flavor profile because the brewer can intentionally leave sweetness in the final beer that will compete with bitterness. A beer that was brewed to be sweet/malty will take more hop bitterness before the drinker can perceive/taste the bitterness; sweetness and bitterness compete with each other. Sweetness can be left in beer during the mash, or added with the choice of yeast and with hops. Hops that are used late in the boil process can produce other flavors like citrus, spice, earth, melon, etc., which will offset bitterness.
The brewer has many options in the brewing process that effect the final bitterness of the beer. The mash schedule used and choice of yeast have an impact on the final perceived bitterness of the beer just as the variety of hops used, and how they are introduced to the boil effect the bitterness profile. Brewers use a calculation to determine the bitterness of beer known as International Bittering Units (IBU). There are other calculations (scales), but IBU is the most widely used scale. Not all beers with 60 IBUs will have the same amount of perceived bitterness. The DuVig IPA, which was released a couple weeks ago, has a measured IBU of 85, but the beer has very little bitterness bite, and lots of hop flavors. If the beer was brewed to be drier, or if late addition hops had not been used, the perceived bitterness bite would be much stronger. This does not mean the bitterness is not there, it just means your palette perceives the flavors in a balanced way. When you hear a beer drinker state, ‘this is a well balanced beer’, they are usually talking about the balance between sweetness and bitterness (and to some extent, ABV).