If university teaches you one thing, it’s that not all beers are created equal. A clear distinction exists between downing lukewarm Pabst in someone's backyard and savouring a hand-crafted brew from the latest hipster start-up.

Besides differences in quality and price, there's a considerable variety in taste across beers. The levels of bitterness, citrus and zest can be higher or lower, but do you know what's actually responsible for altering these flavours in your beer?

You’ve probably heard the term “hops” used to describe beer (and pretended to know what it was, even if you didn't).

The hop plant is vine-like, and interestingly, related to the cannabis plant. Hops are the flowers that the plant produces, which actually look more like green pinecones. These pinecones produce acids, which are used to impart the characteristic acidity, bitterness and/or zest to a particular beer.

Hops are added during the boiling phase of beer-brewing. The grains are heated to release enzymes, which release sugars from within the grain. This occurs before yeast is added, which ferments these sugars and produces alcohol in the process.

The type of flavour that hops provides depends on where and how the hop plant is grown. Generally, beers with a higher level of hops have a much more bitter taste.

The level of hops is classified on a standardized scale. International Bitterness Units (IBU) quantify the level of the breakdown product of the acid from hops that's produced during brewing. Therefore, a higher IBU level indicates greater acidity and a greater influence of hops.

Generally, India Pale Ale (IPA)-style beers have the greatest level of hops (around 60-80 IBUs). Double IPAs have an even higher level, about 80-100 IBUs. 

IPA actually got its name when extra hops were added to beer that was being transported from England to India during the 1800s. It's believed that the hops were able to preserve the beer on the long sea voyage.

Lager and ale-style beers have relatively low hop levels (about 10-20 IBUs). Stouts and porters sit somewhere in the middle, with hop levels around 20-50 IBUs.

The next time “hops” is used to describe a beer, you’ll know exactly what to expect. Go use your newfound wisdom to navigate the craft beer scene with confidence—or at least find a beer you'll actually want to drink sober.