ClubHooligan.com - Burning it up at both ends

Web posted August 9, 2007

'Why does my beer smell like weed?'

By Rachael Juzeler
Bending the Elbow

Rachael Juzeler

Growing hop vines are a sight to behold. When I was a child, my family would drive through Yakima, Wash., past fields of vines climbing on 18-foot trellises of guide wires strung between poles. Two or three of the most vigorous shoots are trained up the wires through the growing season, spinning clockwise. Near harvest, the vines hang heavy and green with the hop cones of the female plant. (Not like the ones in my yard, which are prolific growers but not prolific producers, needing a good, dry harvest season.)

I've had a request to write a column on hops. Specifically to answer the question, "Why does my beer smell like weed?"

The hop plant Humulus lupulus is a relative of the cannabis plant. And like the cannabis plant, the essential ingredients are concentrated in the lupulin glands, found at the base of the bracteoles of the hop cone.

The soft resins in the hop lupulin glands provide bitterness in beer. Alpha acids provide the bulk of the bittering properties as well as help in the formation of foam bubbles, contributing to the stability of the beer head. The acids also inhibit the formation of bacteria in the finished beverage.

Hops were introduced in beer brewing as early as the year 600 and came into widespread use in the 16th century. Hops provide the spicy and bitter qualities to balance out the sweetness of malt and are essential to beer as we know it. Prior to hops, mixtures of spices and herbs called gruit were used to add bitterness to beer.

Hops are added to beer during the boil. If you add the hops at the beginning of the boil, you will extract more of the bittering compounds, or alpha acids, from the hops.

Hops added near the end of the boil will cause the wort to retain more hop aroma and flavor over bittering qualities.

Adding hops after fermentation, referred to as "dry-hopping," will retain the most volatile compounds and can create a very heady, floral, spicy or pungent aroma, depending on the variety of hops used.

There are many varieties of hops, though most are divided into two sub-sets: aroma and bittering hops. Aroma hops generally have a lower alpha acid content, but are highly prized for their aroma and subtle bittering qualities, especially the four European varieties of noble hops. Bittering hops have a higher alpha acid content and generally are considered to be "less refined" in their flavor and aroma characteristics.

Flavor and aroma are attributed to the essential oils of the hop cone. More than 250 chemical compounds appearing in beer have been traced to hop essential oils. Hydrocarbons are a group that accounts for up to 80 percent of hop oil and include myrcene. These compounds are highly volatile and contribute to the fresh hop flavor associated with dry hopping.

Myrcene is one of the major components in the cannabis aroma. The compound myrcene is described as having greater flavor intensity than humulene (the spicy flavor in hops) and is frequently characterized as "pungent." When describing hop flavors, myrcene is described as citrus and piney, and when slightly oxidized as floral.

Sound familiar? Does that answer your question?