




The hop plant, Humulus Lupulus, is a perennial, dioecious bine (the real geeks amongst you know those last two words) that grows in temperate zones all over the world. The part of the plant desired by brewers is properly called an infloresence, but is more commonly referred to as a flower or cone. These flowers resemble soft, green pine cones (see the photo below). At the base of the bracts (the leaves on the cone), near the strig (the central stem of the cone), one will find sticky yellow stuff called lupulin glands. These contain all of the bitter and aromatic substances important to the brewer.

Hops growing wild in Verden, Germany

Hops have been an essential ingredient in beer since the 14th century. Prior to that, spice blends, called gruits, were added to wort to balance malt’s sweetness. The people in those ancient times didn’t understand scientific method very well and often got causality wrong; they spiced their beers with just about anything that didn’t kill them immediately. Illness was more likely to be associated with a black cat or a witch rather than a lifetime of quaffing wormwood-laced beer from a pewter tankard.

Hopped beers gained favor over gruits largely because of their unique, and some would say superior, flavor. Hop plants are also very easy to grow and yield a pretty large crop compared to the amount of effort required of the farmer. They also have very mild antimicrobial properties that help preserve beer (this effect is overstated in most non-professional brewing texts; plenty of wort and beer spoilers laugh in the face of hops).

Bitterness is the primary characteristic brewers want from their hops. Without bitterness, beer would have cloying sweetness. While there are tannins in beer, especially dark styles, their astringency is not usually adequate to give beer a balanced profile. Despite the obvious success of Pepsi, many adults prefer their alcoholic libations to be less cloying.

The bitterness in hops comes from a substance called alpha acid. This stuff is not terribly soluble in wort (unfermented beer), but if it is boiled for 45-60 minutes it undergoes a chemical change (isomerization) that makes it much more useful. Various hop varieties contain different amounts of alpha acid, and this is also variable dependent upon the farm and the growing season. Hop processors analyze each crop for its bitterness potential and report that value to brewers. In this way, brewers are able to adjust the quantities used to obtain consistent bitterness in their beers.

Hops also contain oils that give them a unique aroma best described as “hoppy.” (If only we could transmit odors over the internet.) Some varieties display citrus-like character (Cascade, Amarillo) while others are more peppery (Saaz, Hallertuaer). Some are earthy (Goldings) and others are fruity (Crystal). The list could go on for quite a long time.

The fact that the hop’s bitterness and aromatic properties are derived from different chemicals enables the brewer to control these characteristics independently. It has already been mentioned that hops need to be boiled for a while to yield their bitterness, but this boiling drives off the oils the give aromatic properties to the flowers.

If hops are added to the brew kettle near the end of the boil, the brewer will get little bitterness but preserve some of the aromatic properties. Hops can be added after the boil, just before the wort is chilled, to introduce even more hop aroma to a beer.

Adding hops to the young beer after fermentation will preserve all of the oils but yield no bitterness. This technique is called dry hopping. The aroma thus given to the beer is very much like that of fresh hop flowers. Any beer displaying such a resiny, farm-fresh hop character has most likely been dry-hopped.

Freshness is paramount to hop quality. One can often find hop flowers for sale as herbal supplements at natural foods stores. Stored at room temperature in contact with air, these brownish cones are always wretchedly spoiled, smelling of cheese and easily shattered. Fresh hop flowers are bright green (perhaps with a yellow tint) and smell resiny and sharp when crushed in the hand.

In their natural state hop flowers are highly perishable. After harvest they must be dried quickly, but at low temperature, or they will soon grow moldy. Further, they must be tightly baled, packed in mylar to exclude air and refrigerated. Brewers can buy them in this form, but many of us prefer to use hop pellets.

Hop pellets are nothing more – or less – than hops that have been dried, ground into powder and then compressed into pellets resembling commercial rabbit food. Their low surface area to volume ratio means that they are well protected from air. Their dense structure makes it much easier to vacuum pack and refrigerate  them than whole flowers (they take up less space). This means that they stay fresh much longer than unprocessed flowers.

Hops can also be processed into bittering extracts and essential oils. Larger breweries often use such products (especially the bittering extracts) in order to achieve precise consistency and save money. The monetary savings are not direct; hop extracts are expensive, but leave no trub in the kettle at the end of the boil, so less wort is wasted.

The fact that hops need to be transformed extensively after harvest limits their production to areas that also possess hop processing facilities. The United States and Germany vie for the title of top hop-growing nation, but Germany wins by a lot on a per capita basis. Other notable hop growers are China (they grow more and more as their country gains wealth and a taste for beer) and the Czech Republic.

Here in the U.S. hops are grown in the Pacific Northwest. New York was once the hop growing center of the country, but that changed back at the turn of the 20th century. A combination of drought and disease wiped out most of the state’s hop crop. Farmers fortunate enough to have any crop to sell fetched $5/pound. To put this in perspective, a few years ago I was paying $5/pound to a hop dealer!

Hop farmers found conditions in the Pacific Northwest much more favorable than here in New York. The longer growing season, dry air and plentiful irrigation enabled them to grow plants with much higher yields than ever. Disease was virtually unknown until just this past decade. By the time hop pathogens finally made it out west, effective sprays and modern hop varieties (bred for disease resistance) prevented the catastrophe that destroyed New York’s hop industry a century earlier.

Three years ago there was a modern hop crisis. Hop prices had been  low for many years; so low that many farmers decided that they couldn’t afford to grow them anymore. This most affected American craft brewers, due to the small size of many breweries and the relatively high usage of aroma hops compared to the mega brewers. It didn’t help that the two hop dealers serving craft brewers merged into one entity. Monopolies are never good, and some brewers I’ve spoken with have wondered if the hop crisis of 2007 wasn’t more about price gouging or incompetence than an actual lack of hops.

Most small breweries didn’t contract for hops; who would think they would need to contract for 200 pounds of one variety for a year? Instead, most just bought hops as they needed them on the spot market. Prices were never too high and aside from a couple of varieties (notably Amarillo and Crystal), you could always get what you wanted.

Buying on the spot market was also conducive to experimentation. One could buy quantities as small as 11 pounds, making it easy to try a new hop or a new style of beer. Forward contracting makes this much harder; one must predict their precise hop usage a year in advance, and contracting for 11 pounds of any hop is just silly. It also locks the buyer into this year’s prices. This could be good or very, very bad.

In the panic that ensued after the hop shortage, brewers raced to fill out contracts for the next year’s – or more – hop supply. Prices were very high at the time ($28/pound), but reality was that there was no spot market at all. Many hop varieties could not be had for any price. Many brewers feared that the market would not recover for years and signed contracts at high prices.

At the moment, spot market prices have come back down to about $10/pound, and most varieties can be bought on a whim. This is certainly more reasonable for brewers and, hopefully, sustainable for farmers. Crop reports show acreage continuing to decline world wide, so I fear all is not quite settled.

Another part of the issue is that global demand for hops is dictated by the world’s largest breweries. The American craft beer market, so dependent upon specific aroma hops, is virtually invisible when measured against global beer production. The vast majority of the world’s beers have very little hop flavor or aroma; their brewers care only about bitterness.

Hops that are high in bitterness are what they want farmers to grow, leaving those wanting aroma-quality hops looking at another shortage. A very popular aroma hop, Amarillo, is grown on only 19 acres (the farmer who first bred it is very protective of his stock). Perhaps today’s prices will keep enough farmers in the game, serving the craft brewing community.

If you’ve made it this far, congratulations! You now have more hoppy knowledge than you probably will ever need. In case you really want to know more, here’s some homework:

To experience dry-hopped beers, try any of the following: Southern Tier IPA, Sierra Nevada Torpedo, or my own pale ale or Kick-Ass Brown. Samuel Adams Boston Lager exhibits a very nice Hallertau hop aroma when it is fresh. You will smell that it is not nearly as bold, citrusy and resinous as the aforementioned dry-hopped beers.

By contrast, beer styles with hardly any hop character at all include Hefeweizen, Belgian-style wheats (wit) and Belgian-style dark strong ales.

Have a fun weekend!

George de Piro

One Response

  1. Brendan says:

    What are your thoughts on Albany Ale? This should be your next brewing project: