As far as many American Craft Brewers would be concerned, hops are the best thing that has ever happen to beer – they have very notably become brewers of beers with big rich hopy aromas and flavors. Many U.S. Craft Breweries brew with so many varieties of hops in such large quantities that new styles have been created to fit these new hop heavy beers. Double IPAs, Imperial Bitters, and a huge slew of dry hopped styles are among some of the beers you can find all across the United States these days.
But what is a hop in the first place? What types of flavor characteristics does it impart on beer? Why is it necessary? And what is an IBU anyways?
The hop is a type of flower that not only provides natural preservative qualities to finished beer, but also provides bitterness and a wide range of flavors and aromas. From the viewpoint of the brewers, or chef, hops are a spice.
Some people squirm at the idea of a bitter beer, but it is the chemical bitterness in commodity grade beers which is so unappealing. Bitterness in real beers is often the true backbone of the beer’s flavor, and is required to balance out the natural sweetness that comes from the malts. Without hops, we would either have to use another bittering agent to balance our beers (previously brewers has used gruit, which included in it bog myrtle, yarrow, myrrh, rosemary, ginger, licorice, and more), or we would have wildly sweet, less appetizing, and unbalanced brews. Properly coordinated bitterness lends so many unique and amazing qualities to beer.
What’s a Hop?
The hop plant, Humulus Lupulus, is a perennial vine which is in the order Cannabicea; its closest relative is Cannabis Sativa, or Marijuana. While the English used to stuff their pillows with hops noting that they helped them relax, hops do not provide the same affects as does marijuana, but its physical characteristics are very similar.
Hope vines can grow to be twenty feet or taller during the summer, after which it will shrink down to a woody crown under the soil in the fall. By late summer, hope cones, which look like green pine cones begin to flowed from the vines. Inside each cone at the base is a yellow resinous powder called lupulin – this contains all the characteristics which the brewer is looking for.
Just like wine grapes, hops are varietal; there are dozens to choose from, each imparting their own unique flavor, aromatics, spice and bitter characteristics. Over the years, hop growers have been able to customize their crops to yield specific hops to impart specific unique characteristics: American Cascade hops bring a piney grapefruit crisp bite with them; German Tettnag are very floral and earthy; Czech Saaz hops have a very fine bitterness with delicate floral aromas; and Eglish Fuggles have a earthy fennel flavor and aroma. These days, the list really goes on an on.
Why a Hop?
Hops bring a clean sharp bitterness to beer, without them beer would be sweet, cloying and much less satisfying to drink – not to mention would loose almost off of its refreshing and quenching qualities. Hop bitterness is incredibly good a cutting through foods and cleansing your palate of rich flavors. This along with hops powerful aromatic properties makes hops the perfect ingredient to create a beer which dynamically bonds with so many foods.
Many classical beers are brewed with one, or sometimes two specific hop varieties, but more and more these days breweries are using more varieties together to create truly unique beers with complex hop characteristics. One of my favorite tastings to do is a horizontal hop tasting – you would choose a variety of beers which are relatively similar in style (all IPAs, or ESBs, or Stouts, etc) and choose examples which use different hop varieties. This way you can really break down how specific hops impart unique characteristics.
The first hopped beers appeared in North Germany around the year 1000. At the time, brewing laws imposed by the church decreed that beer must use gruit, a mixture of spices and herbs not so often seen anymore. The German city of Bremen was reasonably out of reach of the church, and were thus not obligated to use gruit. Slowly the hopped beers spread across Germany, to Amsterdam, and eventually England with a flood of Flemish immigrants in 1500.
At first the English were not pleased with serving this foreign beer, however its superior shelf life, and crisp clean taste eventually won them over, and by 1600 all English beer and ales were hopped. Soon after that, all of northern Europe was brewing with hops, and it had become the norm among brewers.
How to Hop?
In order to extract the bitterness from hops they must be boiled, driving off the volatile and aromatic oils. This process happens during the mash, when malted barley is boiled to extract their sugars. The longer the hops sit in the boil, the more bitter characteristics are absorbed into the wort (sugary liquid which will eventually become beer), but also the fewer the flavor characteristics remain. So hops are typically used in multiple additions.
Hops are also used after the boil in a process known as dry hopping. Here, after the wort is created and yeast has been pitched into it, hops will be steeped in the fermenting beer for anywhere from an hour, so days or weeks. This imparts a very raw hop flavor to the beer, and has created some of the most quenching and refreshing beers I can think of. Think of it as steeping a tea bag.
Each hop variety will have its own specific unique qualities, so brewers will have to choose which hops to use for the bittering hops (to be in the boil the longest), and which to use for the flavor hops (to be in the boil for the shortest). Beyond that, the brewer must determine how long each of these hops should be in the boil for, and how much should be used. For brewers, hops come in two primary forms, whole dried hops, and pellet hops. Pellet hops are a dried, concentrated hop that pack a strong and supremely pungent punch. For the same weight, a brewer could use much less volume of pellets compared to whole hops to achieve the same bitter characteristics. whole dried hops are exactly that, and some bres even use fresh wet hops, such as the Sierra Nevada Wet Hop.
Whole hops and pellets each have some advantages and disadvantages. Whole hops are of course the freshest and cleanest flavor, but are more difficult to store, are relatively more expensive, can loose their strength over time, and can be very messy in the mash. Pellets are a concentrated flavor which has been perfected over the years, and the majority of breweries across the world will use pellets. They are standardized per batch, last longer in the fridge and are much easier to weigh out, less expensive, however are not as good for dry hopping, and still do not impart the freshness that a whole hop will. The choice is ultimately up to the brewmaster.
How does Hop = Bitter?
There are many tools these days to help brewers with the multitude of choices that they must make. Every hop variety has a specific amount of bittering potential; it is the alpha acid in the lupulin which is extracted to actually create the bitter sensation. So hops these days all come with an AA Rating so that brewers how its bitterness is, and also can brew the same beers consistently time and time again regardless of how that specific crop turned out.
Beyond that, a measurement called an IBU (International Bitter Unit) exists to aid both brewers and beer drinkers. Essentially, it is a numerical measurement of how bitter a beer is, beginning with zero. But without a true reference point IBUs mean nothing to us. If you begin to pay attention to the IBUs listed on the beers you drink, you will be able to go seek out beers with a bitterness level that you enjoy. For example, the Dogfish Head 60 Minute IPA has 60 IBUs, and Rogue’s Old Crustacean Barleywine has 110 IBUs. Modern commodity grade beers usually have less than 10 IBUs.
Commodity beers also do not list their IBUs, they have absolutely no obligation to. But many American and European Craft Breweries are beginning to list it for the drinkers interest. Like everything else about beer, the more you know about it, the better you can enjoy it. So enjoy!