Hops are undeniably the most hip ingredient used by brewers in crafting tasty beverages these days. Unless you’ve been living under a rock for the last 20 years, you’ve certainly heard of the hop heavy IPA and probably encountered the term dry-hopped, maybe even double dry-hopped. But what exactly are hops, why are they so hip and what does it mean to dry-hop a wet beverage like beer?
Humulus Lupulus (aka hops) is a flowering bine native to North America and Europe. Quick horticultural aside, a bine is a plant that looks like a vine but has tiny hooks on its stalk that allow the plant to climb. But it’s not the stalk or the leaves that we’re interested in from a beer perspective; flower power reigns supreme. The hop flower contains tiny packets of magic called lupulin glands from which we get taste, flavor and aroma. Check out the anatomy of a hop below.
Taste is the perception of certain specific components (bitter, sweet, salty, sour & savory) by the receptors on our tongues. With regards to how hops contribute in this area we focus on bitterness. When hops are boiled in the making of beer, we extract the bittering compounds from the lupulin glands. Brewers measure the amount of these compounds as IBU’s (International Bittering Units). You will frequently find this number referenced on beer labels and it can give you an indication of how bitter the beer will taste.
What we call flavor is actually a combination of the senses of taste and aroma. It is in this area that different varieties of hops begin to show their individuality. Like any plant, the flavors and aromas that we can get from the hop flowers are driven by the plant variety and its growing conditions. For example, think about apples and how the flavors of Golden vs a Red Delicious apples differ; the same is true for hops. The diagram below depicts the various flavors/aromas that can be found in different hop varieties.
However, for most of recent history, that is until the early 1990’s, most hop cultivation was geared towards the demands of macro brewers who desired a maximization of bittering capacity and a minimization of the flavor/aroma components. With the growth of the craft beer industry, hop growers have embraced the pursuit of exotic flavor/aroma compounds that have resulted in new varieties such as Citra, Mosaic and Galaxy, from which brewers are able to coax intense tropical, citrus and stone fruit characters that were previously unknown in beer. It turns out that many beer drinkers very much like the character of these new hops and brewers are constantly pursuing new flavors/aromas in their beers through combinations of new hop varieties and unique methods of incorporating the hops into the beer making process. And that is what makes hops hip and why beers with the letters IPA (as short hand for hoppy beer) are ubiquitous in the beer aisle and at your local watering hole.
Now what about this dry hopping business? There’s certainly nothing dry about it unless we point out hops are (generally, but not always) dried after harvest for storage before being delivered to the brewers, but that doesn’t explain why brewers call the process of adding hops during or after fermentation dry hopping. Leaving the nomenclature behind, its important for beer consumers to understand when a brewer tells us a beer has been dry hopped we should expect an intense hop aroma and an amplified hop flavor in the beer we are about to drink.
One final note to guide you in exploring hop forward beers. The intense fruit flavor/aroma of hops in beer is fleeting so it is important to look for a “packaged on” or “best by” date on IPA’s or other dry hopped beers. The beers do not go bad per se, but over the course of a couple months, the hop character will change, sometimes dramatically, to something different than what the brewer intended. You may still enjoy an IPA that is 6 months old, but it will most certainly taste different than it did when it was packaged. So its best to sip sooner than later!
Happy hop hunting!